Science.gov

Sample records for jupiter mass planets

  1. Constraining the mass of a rotating extrasolar Jupiter-like planet from its shape

    NASA Astrophysics Data System (ADS)

    Zhang, Keke; Kong, Dali; Schubert, Gerald

    2015-08-01

    We discuss, via an example of the planet beta Pictoris b, a theoretical method for constraining the mass of a rapidly rotating extrasolar Jupiter-like planet from its shape. This young extrasolar gaseous planet recently discovered in the beta Pictoris system spins substantially faster than the gas giant planets Jupiter and Saturn, but its mass remains highly uncertain. Based on the measured parameters (such as the rotation speed and the radius) of the planet, we are able to compute, via a hybrid inverse method, its non-spherical shape, internal density/pressure distribution and gravitational zonal coefficients. We show that, if the shape of an extrasolar gaseous planet can be measured or constrained like that of the exoplanet HD 189733b, the mass of the planet can be inferred through a theoretical relationship between the shape and the mass.

  2. Final Masses of Giant Planets II: Jupiter Formation in a Gas-Depleted Disk

    NASA Astrophysics Data System (ADS)

    Tanigawa, Takayuki; Tanaka, Hidekazu

    2015-12-01

    Firstly, we study the final masses of giant planets growing in protoplanetary disks through capture of disk gas, by employing an empirical formula for the gas capture rate and a shallow disk gap model, which are both based on hydrodynamical simulations. The shallow disk gaps cannot terminate growth of giant planets. For planets less massive than 10 Jupiter masses, their growth rates are mainly controlled by the gas supply through the global disk accretion, rather than their gaps. The insufficient gas supply compared with the rapid gas capture causes a depletion of the gas surface density even at the outside of the gap, which can create an inner hole in the protoplanetary disk. Our model can also predict how deep the inner hole is for a given planet mass. Secondly, our findings are applied to the formation of our solar system. For the formation of Jupiter, a very low-mass gas disk with a few or several Jupiter masses is required at the beginning of its gas capture because of the non-stopping capture. Such a low-mass gas disk with sufficient solid material can be formed through viscous evolution from an initially ˜10AU-sized compact disk with the solar composition. By the viscous evolution with a moderate viscosity of ?˜10-3, most of disk gas accretes onto the sun and a widely spread low-mass gas disk remains when the solid core of Jupiter starts gas capture at t˜107 yrs. The depletion of the disk gas is suitable for explaining the high metallicity in giant planets of our solar system. A very low-mass gas disk also provides a plausible path where type I and II planetary migrations are both suppressed significantly. In particular, we also show that the type II migration of Jupiter-size planets becomes inefficient because of the additional gas depletion due to the rapid gas capture by themselves.

  3. Accretion of Jupiter-mass planets in the limit of vanishing viscosity

    SciTech Connect

    Szulágyi, J.; Morbidelli, A.; Crida, A.; Masset, F.

    2014-02-20

    In the core-accretion model, the nominal runaway gas-accretion phase brings most planets to multiple Jupiter masses. However, known giant planets are predominantly Jupiter mass bodies. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in the low-viscosity regime, or both. Here we explore the second way by using global, three-dimensional isothermal hydrodynamical simulations with eight levels of nested grids around the planet. In our simulations, the vertical inflow from the circumstellar disk (CSD) to the CPD determines the shape of the CPD and its accretion rate. Even without a prescribed viscosity, Jupiter's mass-doubling time is ?10{sup 4} yr, assuming the planet at 5.2 AU and a Minimum Mass Solar Nebula. However, we show that this high accretion rate is due to resolution-dependent numerical viscosity. Furthermore, we consider the scenario of a layered CSD, viscous only in its surface layer, and an inviscid CPD. We identify two planet-accretion mechanisms that are independent of the viscosity in the CPD: (1) the polar inflow—defined as a part of the vertical inflow with a centrifugal radius smaller than two Jupiter radii and (2) the torque exerted by the star on the CPD. In the limit of zero effective viscosity, these two mechanisms would produce an accretion rate 40 times smaller than in the simulation.

  4. Final Masses of Giant Planets II: Jupiter Formation in a Gas-Depleted Disk

    E-print Network

    Tanigawa, Takayuki

    2015-01-01

    Firstly, we study the final masses of giant planets growing in protoplanetary disks through capture of disk gas, by employing an empirical formula for the gas capture rate and a shallow disk gap model, which are both based on hydrodynamical simulations. The shallow disk gaps cannot terminate growth of giant planets. For planets less massive than 10 Jupiter masses, their growth rates are mainly controlled by the gas supply through the global disk accretion, rather than their gaps. The insufficient gas supply compared with the rapid gas capture causes a depletion of the gas surface density even at the outside of the gap, which can create an inner hole in the protoplanetary disk. Our model can also predict the depleted gas surface density in the inner hole for a given planet mass. Secondly, our findings are applied to the formation of our solar system. For the formation of Jupiter, a very low-mass gas disk with a few or several Jupiter masses is required at the beginning of its gas capture because of the non-sto...

  5. Jupiter: As a planet. [its physical characteristics and radio waves emitted from Jupiter

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The planet Jupiter, its planetary mass and atmosphere, radio waves emitted from Jupiter, thermal radiation, internal structure of Jupiter, and the possibility of life on Jupiter are discussed. Educational study projects are included.

  6. Formation of Jupiter-mass planets from hydrodynamic simulations -- the role of the circumplanetary disk in the accretion process

    NASA Astrophysics Data System (ADS)

    Szulagyi, Judit; Morbidelli, Alessandro; Masset, Frederic; Lega, Elena; Crida, Aurelien; Guillot, Tristan

    2015-12-01

    In the era of observing young planetary systems with growing planets, it is necessary to study planet formation with numerical simulations to provide predictions for observations and also to update planet formation models. In this talk we are going to summarize a PhD thesis on the topic of accretion of giant planets with hydrodynamic simulations.One of the main problems with the core accretion formation model is that it predicts a runaway growth phase for the giant planets at the last stages of the formation process, which would indicate a presence of an unseen population of super-giants. We performed isothermal and radiative hydrodynamic simulations in 3D on a Jupiter-mass planet in an MMSN disk to simulate the fastest part of the runaway growth for our Jupiter. This massive planet can form a circumplanetary disk around it, which can limit the accretion in this late stage of planet formation, and is the focus point of our study. We have found that the 90% of the accreted gas by the planet is coming from the vertical direction, from the top layers of the circumstellar disk falling through the planetary gap, in an inflow hitting the circumplanetary disk and directly the planet as well. We will show that this vertical influx is part of a feedback loop -- a meridional circulation -- between the circumstellar and circumplanetary disks.We have also revisited the question of circumplanetary disk formation. Planets which are massive enough to open gaps (above ~Saturn's mass) were believed to form circumplanetary disk, while planets below this mass threshold were only capable to form an envelope. We will prove that the planetary surface temperature is also playing a large role in this question. We carried out a series of simulations with various planetary surface temperatures, and found that in the hottest case even a Jupiter-mass planet, which was capable to open a planetary gap, cannot form a circumplanetary disk, only an envelope, similarly to small mass planets. We will show the quantitative differences between the envelope and disk cases which have implications on the satellite formation and for the future observations of circumplanetary disks/envelopes around giant planets as well.

  7. Dust Coagulation in the Vicinity of a Gap-Opening Jupiter-Mass Planet

    E-print Network

    Carballido, Augusto; Hyde, Truell W

    2015-01-01

    We analyze the coagulation of dust in and around a gap opened by a Jupiter-mass planet. To this end, we carry out a high-resolution magnetohydrodynamic (MHD) simulation of the gap environment, which is turbulent due to the magnetorotational instability. From the MHD simulation, we obtain values of the gas velocities, densities and turbulent stresses a) close to the gap edge, b) in one of the two gas streams that accrete onto the planet, c) inside the low-density gap, and d) outside the gap. The MHD values are then supplied to a Monte Carlo dust coagulation algorithm, which models grain sticking and compaction. We consider two dust populations for each region: one whose initial size distribution is monodisperse, with monomer radius equal to 1 $\\mu$m, and another one whose initial size distribution follows the Mathis-Rumpl-Nordsieck distribution for interstellar dust grains, with an initial range of monomer radii between 0.5 and 10 $\\mu$m. Our Monte Carlo calculations show initial growth of dust aggregates foll...

  8. Jupiter: Lord of the Planets.

    ERIC Educational Resources Information Center

    Kaufmann, William

    1984-01-01

    Presents a chapter from an introductory college-level astronomy textbook in which full-color photographs and numerous diagrams highlight an extensive description of the planet Jupiter. Topics include Jupiter's geology, rotation, magnetic field, atmosphere (including clouds and winds), and the Great Red Spot. (DH)

  9. ACCRETION OF ROCKY PLANETS BY HOT JUPITERS

    SciTech Connect

    Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M.

    2011-11-01

    The observed population of Hot Jupiters displays a stunning variety of physical properties, including a wide range of densities and core sizes for a given planetary mass. Motivated by the observational sample, this Letter studies the accretion of rocky planets by Hot Jupiters, after the Jovian planets have finished their principal migration epoch and become parked in {approx}4 day orbits. In this scenario, rocky planets form later and then migrate inward due to torques from the remaining circumstellar disk, which also damps the orbital eccentricity. This mechanism thus represents one possible channel for increasing the core masses and metallicities of Hot Jupiters. This Letter determines probabilities for the possible end states for the rocky planet: collisions with the Jovian planets, accretion onto the star, ejection from the system, and long-term survival of both planets. These probabilities depend on the mass of the Jovian planet and its starting orbital eccentricity, as well as the eccentricity damping rate for the rocky planet. Since these systems are highly chaotic, a large ensemble (N {approx} 10{sup 3}) of simulations with effectively equivalent starting conditions is required. Planetary collisions are common when the eccentricity damping rate is sufficiently low, but are rare otherwise. For systems that experience planetary collisions, this work determines the distributions of impact velocities-both speeds and impact parameters-for the collisions. These velocity distributions help determine the consequences of the impacts, e.g., where energy and heavy elements are deposited within the giant planets.

  10. The planet Jupiter (1970)

    NASA Technical Reports Server (NTRS)

    Divine, N.

    1971-01-01

    Data obtained through 1970, some materials published during the first half of 1971, and conclusions of the Jupiter Radiation Belt Workshop held in July 1971 are presented. All the information on Jupiter was derived from data obtained at angular and spectral resolutions possible with Earth-based instrumentation or with sensors on aircraft, rockets, and balloons. The observations were made primarily in the visible, near visible, infrared, and radio portions of the electromagnetic spectrum. The information was assessed for the potential effects of the Jovian environment on spacecraft performance. The assessment was done independently for the three types of missions under consideration and formulated for overall spacecraft as well as for subsystem design.

  11. Atmospheric mass loss from Hot Jupiters: chemical reactions and a new hypothesis for the origin of water in habitable planets

    NASA Astrophysics Data System (ADS)

    Pinotti, Rafael; Boechat-Roberty, Heloisa M.

    2015-08-01

    The chemistry along the mass loss of Hot Jupiters is generally considered to be simple, consisting mainly of atoms, prevented from forming more complex species by the intense radiation field from their host stars. However, the results of our chemical reaction simulations, involving 56 species and 566 reactions, indicate that many simple molecules, including H2O+ and OH+, are formed along the mass loss of HD 209458 b and analogs, in a region farther away from the planet, where the temperature is lower (T < 2000 K). Our simulations included benzene formation reactions; the results indicate that carbon chain species are not formed in the mass loss of HD 209458 b. We also formulate a new hypothesis for the origin of water on the surface of habitable planets in general: chemical interaction of their primordial atmospheres with hydrogen and oxygen ions from the atmospheric mass loss of primordial, low density Hot Jupiters. This mechanism could have possibly operated in the Solar System and accounted for the formation of the oceans of the Earth.

  12. Accretion of Rocky Planets By Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Ketchum, Jake; Adams, F.; Bloch, A.

    2012-05-01

    The observed population of Hot Jupiters displays a stunning variety of physical properties, including a wide range of densities and core sizes for a given planetary mass. Motivated by the observational sample, this work studies the accretion of rocky planets by Hot Jupiters, after the Jovian planets have finished their principal migration epoch and become parked in 4 day orbits. In this scenario, rocky planets form later and then migrate inward due to torques from the remaining circumstellar disk, which also damps the orbital eccentricity. This mechanism thus represents one possible channel for increasing the core masses and metallicities of Hot Jupiters. This work determines probabilities for the possible end states for the rocky planet: collisions with the Jovian planets, accretion onto the star, ejection from the system, and long-term survival of both planet. These probabilities depend on the mass of the Jovian planet and its starting orbital eccentricity, as well as the eccentricity damping rate for the rocky planet. Since these systems are highly chaotic, a large ensemble (N 1000) of simulations with effectively equivalent starting conditions is required. Planetary collisions are common when the eccentricity damping rate is sufficiently low, but are rare otherwise. For systems that experience planetary collisions, this work determines the distributions of impact velocities -- both speeds and impact parameters -- for the collisions. These velocity distributions help determine the consequences of the impacts, e.g.,where energy and heavy elements are deposited within the giant planets. This work was supported by NSF grant DMS-0806756 from the Division of Applied Mathematics, NASA grant NNX11AK87G, and NSF grant DMS-0907949.

  13. Eccentric Jupiters via Disk-Planet Interactions

    NASA Astrophysics Data System (ADS)

    Duffell, Paul C.; Chiang, Eugene

    2015-10-01

    Numerical hydrodynamics calculations are performed to determine the conditions under which giant planet eccentricities can be excited by parent gas disks. Unlike in other studies, Jupiter-mass planets are found to have their eccentricities amplified—provided their orbits start off as eccentric. We disentangle the web of co-rotation, co-orbital, and external resonances to show that this finite-amplitude instability is consistent with that predicted analytically. Ellipticities can grow until they reach of order of the disk's aspect ratio, beyond which the external Lindblad resonances that excite eccentricity are weakened by the planet's increasingly supersonic epicyclic motion. Forcing the planet to still larger eccentricities causes catastrophic eccentricity damping as the planet collides into gap walls. For standard parameters, the range of eccentricities for instability is modest; the threshold eccentricity for growth (˜0.04) is not much smaller than the final eccentricity to which orbits grow (˜0.07). If this threshold eccentricity can be lowered (perhaps by non-barotropic effects), and if the eccentricity driving documented here survives in 3D, it may robustly explain the low-to-moderate eccentricities ?0.1 exhibited by many giant planets (including Jupiter and Saturn), especially those without planetary or stellar companions.

  14. Evaporation rate of hot Jupiters and formation of Chthonian planets

    E-print Network

    G. Hébrard; A. Lecavelier des Étangs; A. Vidal-Madjar; J. -M. Désert; R. Ferlet

    2003-12-15

    Among the hundred of known extrasolar planets, about 15% are closer than 0.1 AU from their parent stars. But there are extremely few detections of planets orbiting in less than 3 days. At this limit the planet HD209458b has been found to have an extended upper atmosphere of escaping hydrogen. This suggests that the so-called hot Jupiters which are close to their parent stars could evaporate. Here we estimate the evaporation rate of hydrogen from extrasolar planets in the star vicinity. With high exospheric temperatures, and owing to the tidal forces, planets evaporate through a geometrical blow-off. This may explain the absence of Jupiter mass planets below a critical distance from the stars. Below this critical distance, we infer the existence of a new class of planets made of the residual central core of former hot Jupiters, which we propose to call the ``Chthonian'' planets.

  15. KELT-10b and KELT-11b: Two Sub-Jupiter Mass Planets well-Suited for Atmospheric Characterization in the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Rodriguez, Joseph E.

    2015-12-01

    The Kilodegree Extremely Little Telescope (KELT) project is a photometric survey in both the northern and southern hemispheres for transiting planets around bright stars (8 < V < 11), and has discovered 15 planets to date. Of these, several possess unique characteristics that make them especially well suited for study of planet atmospheres. Here, I present the first two discoveries from the KELT-South survey. KELT-10b is an inflated transiting sub-Jupiter mass planet (0.68 MJ) around a V=10.7 early G-star. It has the 3rd deepest transit (1.4%) in the southern hemisphere for a star V < 12.5, making it a great target for transmission spectroscopy. KELT-11b is a highly inflated transiting Saturn mass planet (0.22 MJ) orbiting one of the brightest planet-hosting stars in the southern hemisphere. Interestingly, KELT-11b's host star is a clear sub-giant star (log(g) ~ 3.7). I will discuss their impact for atmospheric characterization. For example, the highly inflated nature of the KELT-11b planet provides the ability to study a sub-Jupiter atmosphere at very low planetary gravity, while the sub-giant nature of its host star allows us to study the effects of post main sequence evolution of a host star on a hot Jupiter.

  16. Hot Jupiters from secular planet-planet interactions.

    PubMed

    Naoz, Smadar; Farr, Will M; Lithwick, Yoram; Rasio, Frederic A; Teyssandier, Jean

    2011-05-12

    About 25 per cent of 'hot Jupiters' (extrasolar Jovian-mass planets with close-in orbits) are actually orbiting counter to the spin direction of the star. Perturbations from a distant binary star companion can produce high inclinations, but cannot explain orbits that are retrograde with respect to the total angular momentum of the system. Such orbits in a stellar context can be produced through secular (that is, long term) perturbations in hierarchical triple-star systems. Here we report a similar analysis of planetary bodies, including both octupole-order effects and tidal friction, and find that we can produce hot Jupiters in orbits that are retrograde with respect to the total angular momentum. With distant stellar mass perturbers, such an outcome is not possible. With planetary perturbers, the inner orbit's angular momentum component parallel to the total angular momentum need not be constant. In fact, as we show here, it can even change sign, leading to a retrograde orbit. A brief excursion to very high eccentricity during the chaotic evolution of the inner orbit allows planet-star tidal interactions to rapidly circularize that orbit, decoupling the planets and forming a retrograde hot Jupiter. PMID:21562558

  17. Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

    NASA Astrophysics Data System (ADS)

    Gillon, M.; Anderson, D. R.; Triaud, A. H. M. J.; Hellier, C.; Maxted, P. F. L.; Pollaco, D.; Queloz, D.; Smalley, B.; West, R. G.; Wilson, D. M.; Bentley, S. J.; Collier Cameron, A.; Enoch, B.; Hebb, L.; Horne, K.; Irwin, J.; Joshi, Y. C.; Lister, T. A.; Mayor, M.; Pepe, F.; Parley, N.; Segransan, D.; Udry, S.; Wheatley, P. J.

    2009-07-01

    We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060+ 0.0000022 - 0.0000035 days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass Mp = 0.503+0.019-0.038 MJ and radius Rp = 1.224+0.051-0.052 R_J, resulting in a density ?p = 0.27 ± 0.05 ?_J. The mass and radius for the host star are M_ast = 0.88+0.05-0.08 M_? and R_ast = 0.870+0.025-0.036 R_?. The non-zero orbital eccentricity e = 0.054^+0.018-0.015 that we measure suggests that the planet underwent a massive tidal heating 1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis ? = 11+14-18 deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk. Based on data collected with the HARPS spectrograph at ESO La Silla Observatory in the programs 082.C-0040(E) and 082.C-0608. The photometric time-series and radial velocities (Tables 4, 5) used in this work are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/501/785

  18. Kepler constraints on planets near hot Jupiters

    SciTech Connect

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2:1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  19. Kepler constraints on planets near hot Jupiters.

    PubMed

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  20. Kepler constraints on planets near hot Jupiters

    PubMed Central

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

    2012-01-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2?1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  1. Exploring the diversity of Jupiter-class planets.

    PubMed

    Fletcher, Leigh N; Irwin, Patrick G J; Barstow, Joanna K; de Kok, Remco J; Lee, Jae-Min; Aigrain, Suzanne

    2014-04-28

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1?AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term 'hot Jupiter' fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the available data, and the requirements for future spectroscopic characterization of a set of Jupiter-class objects to test our physical and chemical understanding of these planets. PMID:24664910

  2. Exploring the diversity of Jupiter-class planets

    PubMed Central

    Fletcher, Leigh N.; Irwin, Patrick G. J.; Barstow, Joanna K.; de Kok, Remco J.; Lee, Jae-Min; Aigrain, Suzanne

    2014-01-01

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1?AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term ‘hot Jupiter’ fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the available data, and the requirements for future spectroscopic characterization of a set of Jupiter-class objects to test our physical and chemical understanding of these planets. PMID:24664910

  3. There might be giants: unseen Jupiter-mass planets as sculptors of tightly-packed planetary systems

    E-print Network

    Hands, T O

    2015-01-01

    The limited completeness of the Kepler sample for planets with orbital periods $\\gtrsim$ 1 yr leaves open the possibility that exoplanetary systems may host undetected giant planets. Should such planets exist, their dynamical interactions with the inner planets may prove vital in sculpting the final orbital configurations of these systems. Using an $N$-body code with additional forces to emulate the effects of a protoplanetary disc, we perform simulations of the assembly of compact systems of super-Earth-mass planets with unseen giant companions. The simulated systems are analogous to Kepler-11 or Kepler-32 in that they contain 4 or 5 inner super-Earths, but our systems also contain longer-period giant companions which are unlikely to have been detected by Kepler. We find that giant companions tend to break widely-spaced, first-order mean-motion resonances, allowing the inner planets to migrate into tighter resonances. This leads to more compact architectures and increases the occurrence rate of Laplace reson...

  4. The Observational Case for Jupiter Being a Typical Massive Planet

    E-print Network

    Lineweaver, Charles H.

    The Observational Case for Jupiter Being a Typical Massive Planet CHARLES H. LINEWEAVER and DANIEL in the period-M sin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus indicating that Jupiter is a typical massive planet rather than

  5. Can Terrestrial Planets Form in Hot-Jupiter Systems?

    E-print Network

    Martyn J. Fogg; Richard P. Nelson

    2007-10-19

    Models of terrestrial planet formation in the presence of a migrating giant planet have challenged the notion that hot-Jupiter systems lack terrestrial planets. We briefly review this issue and suggest that hot-Jupiter systems should be prime targets for future observational missions designed to detect Earth-sized and potentially habitable worlds.

  6. HAT-P-28b AND HAT-P-29b: TWO SUB-JUPITER MASS TRANSITING PLANETS

    SciTech Connect

    Buchhave, L. A.; Bakos, G. A.; Hartman, J. D.; Torres, G.; Latham, D. W.; Noyes, R. W.; Esquerdo, G. A.; Beky, B.; Sasselov, D. D.; Furesz, G.; Quinn, S. N.; Stefanik, R. P.; Szklenar, T.; Andersen, J.; Kovacs, G.; Shporer, A.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.

    2011-06-01

    We present the discovery of two transiting exoplanets. HAT-P-28b orbits a V = 13.03 G3 dwarf star with a period P = 3.2572 days and has a mass of 0.63 {+-} 0.04 M{sub J} and a radius of 1.21{sup +0.11}{sub -0.08} R{sub J} yielding a mean density of 0.44 {+-} 0.09 g cm{sup -3}. HAT-P-29b orbits a V = 11.90 F8 dwarf star with a period P = 5.7232 days and has a mass of 0.78{sup +0.08}{sub -0.04} M{sub J} and a radius of 1.11{sup +0.14}{sub -0.08} R{sub J} yielding a mean density of 0.71 {+-} 0.18 g cm{sup -3}. We discuss the properties of these planets in the context of other known transiting planets.

  7. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    NASA Astrophysics Data System (ADS)

    Cloutier, Ryan; Tamayo, Daniel; Valencia, Diana

    2015-11-01

    Models of the dynamical evolution of the early solar system that follow the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant (IG) mass, which gets ejected by a gas giant during the early solar system’s proposed instability phase. We investigate the likelihood of an IG ejection (IGE) event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus, respectively. We show that planetary encounters that are sufficient to eject an IG often provide excessive perturbations to the orbits of Callisto and Iapetus, making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite orbit with the current orbit of Callisto following an IGE by Jupiter of ?42%, and conclude that such a large likelihood supports the hypothesis of a fifth giant planet’s existence. A similar calculation for Iapetus reveals that it is much more difficult for Saturn to have ejected an IG and reconciled a Kronian satellite orbit with that of Iapetus (likelihood ?1%), although uncertainties regarding the formation of Iapetus, with its unusual orbit, complicates the interpretation of this result.

  8. A Hot Jupiter for Breakfast? Early Stellar Ingestion of Planets May Be Common

    NASA Astrophysics Data System (ADS)

    Matsakos, Titos; Königl, Arieh

    2015-08-01

    Models of planet formation and evolution predict that giant planets form efficiently in protoplanetary disks, that most of these migrate rapidly to the disk’s inner edge, and that, if the arriving planet’s mass is ? Jupiter’s mass, then it could remain stranded near that radius. We argue that such planets would be ingested by tidal interaction with the host star on a timescale ? 1 Gyr, and that, in the case of a solar-type host, this would cause the stellar spin to approach the direction of the ingested planet’s orbital axis even if the two were initially highly misaligned. Primordially misaligned stars whose effective temperatures are ? 6250 K cannot be realigned in this way because, in contrast with solar-type hosts, their angular momenta are typically higher than the orbital angular momentum of the ingested planet as a result of inefficient magnetic braking and of a comparatively large moment of inertia. Hot Jupiters located farther out from the star can contribute to this process, but their effect is weaker because the tidal interaction strength decreases rapidly with increasing semimajor axis. We demonstrate that, if ? 50% of planetary systems harbored a stranded hot Jupiter, this scenario can in principle account for (1) the good alignment exhibited by planets around cool stars irrespective of the planet’s mass or orbital period, (2) the prevalence of misaligned planets around hot stars, (3) the apparent upper bound on the mass of hot Jupiters on retrograde orbits, and (4) the inverse correlation between stellar spin periods and hot-Jupiter masses.

  9. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    E-print Network

    Cloutier, Ryan; Valencia, Diana

    2015-01-01

    Models of the dynamical evolution of the early solar system following the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant mass, which gets ejected by a gas giant during the early solar system's proposed instability phase. We investigate the likelihood of an ice giant ejection event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus respectively. We show that planetary encounters that are sufficient to eject an ice giant, often provide excessive perturbations to the orbits of Callisto and Iapetus making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite ...

  10. JUPITER WILL BECOME A HOT JUPITER: CONSEQUENCES OF POST-MAIN-SEQUENCE STELLAR EVOLUTION ON GAS GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Madhusudhan, Nikku E-mail: Nikku.Madhusudhan@yale.edu

    2012-09-10

    When the Sun ascends the red giant branch (RGB), its luminosity will increase and all the planets will receive much greater irradiation than they do now. Jupiter, in particular, might end up more highly irradiated than the hot Neptune GJ 436b and, hence, could appropriately be termed a 'hot Jupiter'. When their stars go through the RGB or asymptotic giant branch stages, many of the currently known Jupiter-mass planets in several-AU orbits will receive levels of irradiation comparable to the hot Jupiters, which will transiently increase their atmospheric temperatures to {approx}1000 K or more. Furthermore, massive planets around post-main-sequence stars could accrete a non-negligible amount of material from the enhanced stellar winds, thereby significantly altering their atmospheric chemistry as well as causing a significant accretion luminosity during the epochs of most intense stellar mass loss. Future generations of infrared observatories might be able to probe the thermal and chemical structure of such hot Jupiters' atmospheres. Finally, we argue that, unlike their main-sequence analogs (whose zonal winds are thought to be organized in only a few broad, planetary-scale jets), red-giant hot Jupiters should have multiple, narrow jets of zonal winds and efficient day-night redistribution.

  11. On the origin of the Trojan asteroids: Effects of Jupiter's mass accretion and radial migration

    E-print Network

    Hamilton, Douglas P.

    On the origin of the Trojan asteroids: Effects of Jupiter's mass accretion and radial migration illustrate the effects of Jupiter's accretion of nebular gas and the planet's radial migration on its Trojan that Jupiter's thirty­fold growth from a 10M \\Phi core to its present mass causes the libration amplitudes

  12. Scientists Revise Thinking on Comets, Planet Jupiter

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses scientific information obtained from Pioneer 10's Jupiter flyby and the comet Kohoutek's first trip around the sun, including the high hydrogen emission of Jupiter's principal moon, Io. (CC)

  13. MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS

    SciTech Connect

    Beauge, C.; Nesvorny, D.

    2012-06-01

    Doppler and transit observations of exoplanets show a pile-up of Jupiter-size planets in orbits with a 3 day period. A fraction of these hot Jupiters have retrograde orbits with respect to the parent star's rotation, as evidenced by the measurements of the Rossiter-McLaughlin effect. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization and migration of planets that evolved into highly eccentric orbits. We considered planetary systems having three and four planets initially placed in successive mean-motion resonances, although the angles were taken randomly to ensure orbital instability in short timescales. The simulations included the tidal and relativistic effects, and precession due to stellar oblateness. Our results show the formation of two distinct populations of hot Jupiters. The inner population (Population I) is characterized by semimajor axis a < 0.03 AU and mainly formed in the systems where no planetary ejections occurred. Our follow-up integrations showed that this population was transient, with most planets falling inside the Roche radius of the star in <1 Gyr. The outer population of hot Jupiters (Population II) formed in systems where at least one planet was ejected into interstellar space. This population survives the effects of tides over >1 Gyr and fits nicely the observed 3 day pile-up. A comparison between our three-planet and four-planet runs shows that the formation of hot Jupiters is more likely in systems with more initial planets. Due to the large-scale chaoticity that dominates the evolution, high eccentricities and/or high inclinations are generated mainly by close encounters between the planets and not by secular perturbations (Kozai or otherwise). The relative proportion of retrograde planets seems of be dependent on the stellar age. Both the distribution of almost aligned systems and the simulated 3 day pile-up also fit observations better in our four-planet simulations. This may suggest that the planetary systems with observed hot Jupiters were originally rich in the number of planets, some of which were ejected. In a broad perspective, our work therefore hints on an unexpected link between the hot Jupiters and recently discovered free floating planets.

  14. Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary

    NASA Astrophysics Data System (ADS)

    Anderson, D. R.; Collier Cameron, A.; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Gómez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G.

    2014-12-01

    We report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V ˜ 10). WASP-69b is a bloated Saturn-mass planet (0.26 MJup, 1.06 RJup) in a 3.868-d period around an active, ˜1-Gyr, mid-K dwarf. ROSAT detected X-rays 60±27 arcsec from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ˜1012 g s-1. This is one to two orders of magnitude higher than the evaporation rate estimated for HD 209458b and HD 189733b, both of which have exhibited anomalously large Lyman ? absorption during transit. WASP-70Ab is a sub-Jupiter-mass planet (0.59 MJup, 1.16 RJup) in a 3.713-d orbit around the primary of a spatially resolved, 9-10-Gyr, G4+K3 binary, with a separation of 3.3 arcsec (?800 au). WASP-84b is a sub-Jupiter-mass planet (0.69 MJup, 0.94 RJup) in an 8.523-d orbit around an active, ˜1-Gyr, early-K dwarf. Of the transiting planets discovered from the ground to date, WASP-84b has the third-longest period. For the active stars WASP-69 and WASP-84, we pre-whitened the radial velocities using a low-order harmonic series. We found that this reduced the residual scatter more than did the oft-used method of pre-whitening with a fit between residual radial velocity and bisector span. The system parameters were essentially unaffected by pre-whitening.

  15. The Mass Distribution Function of Planets

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu

    2015-07-01

    The distribution of orbital period ratios of adjacent planets in extrasolar planetary systems discovered by the Kepler space telescope exhibits a peak near ˜1.5-2, a long tail of larger period ratios, and a steep drop-off in the number of systems with period ratios below ˜1.5. We find from these data that the dimensionless orbital separations have an approximately log-normal distribution. Using Hill’s criterion for the dynamical stability of two planets, we find an upper bound on planet masses such that the most common planet mass does not exceed {10}-3.2{m}*, or about two-thirds of Jupiter’s mass for solar-mass stars. Assuming that the mass ratio and the dynamical separation (orbital spacings in units of mutual Hill radius) of adjacent planets are independent random variates, and adopting empirical distributions for these, we use Hill’s criterion in a statistical way to estimate the planet mass distribution function from the observed distribution of orbital separations. We find that the planet mass function is peaked in logarithm of mass, with a peak value and standard deviation of {log}m/{M}\\oplus of ˜ (0.6-1.0) and ˜ (1.1-1.2), respectively.

  16. Properties of the short period CoRoT-planet population II: The impact of loss processes on planet masses from Neptunes to Jupiters

    E-print Network

    Helmut Lammer; T. Penz; G. Wuchterl; H. I. M. Lichtenegger; M. L. Khodachenko; Yu. N. Kulikov; G. Micela

    2007-01-19

    The orbital distance at which close-in exoplanets maintain their initial mass is investigated by modelling the maximum expected thermal and nonthermal mass loss rates over several Gyr. Depending on an exosphere formation time and the evolution of the stellar X-ray and EUV flux we expect that thermal evaporation at orbital distances less than 0.05 AU may be an efficient loss process for hydrogen-rich exoplanets with masses less than 0.25 MJup. Our results indicate that nonthermal mass loss induced by Coronal Mass Ejections of the host star can significantly erode weakly magnetized short periodic gas giants. The observed exoplanets Gliese 876d at 0.0208 AU with a mass of about 0.033 MJup and 55 Cnc e at 0.045 AU with a mass of about 0.038 MJup could be strongly eroded gas giants, while HD69830b, at 0.078 AU, HD160691d at 0.09 AU and HD69830c at 0.18 AU belonged most likely since their origin to the Neptune-mass domain. The consequences for the planetary population predicted in paper I (Wuchterl et al. 2006) for CoRoTs first field are: (1) for orbital distances less than 0.05 AU (orbital periods less than days) weakly magnetized or highly irradiated gas giants may loose a large fraction of their initial mass and completely loose their gas envelopes. (2) Observed planetary mass spectra at these periods that resemble the initial ones would indicate a major effect of magnetic field protection and so far unknown thermospheric cooling processes. (3) At distances larger than 0.05 AU the impact of loss processes is minor and the observed mass spectra should be close to the initial ones.

  17. Planet Masses from Disk Spirals

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Young, forming planets can generate immense spiral structures within their protoplanetary disks. A recent study has shown that observations of these spiral structures may allow astronomers to measure the mass of the planets that create them.Spirals From WavesSnapshots of the surface density of a protoplanetary disk in a 2D simulation, 3D simulation, and synthesized scattered-light image. Click for a closer look! [Fung Dong, 2015]Recent studies have shown that a single planet, if it is massive enough, can excite multiple density waves within a protoplanetary disk as it orbits. These density waves can then interfere to produce a multiple-armed spiral structure in the disk inside of the planets orbit a structure which can potentially be observed in scattered-light images of the disk.But what do these arms look like, and what factors determine their structure? In a recently published study, Jeffrey Fung and Ruobing Dong, two researchers at the University of California at Berkeley, have modeled the spiral arms in an effort to answer these questions.Arms Provide AnswersA useful parameter for describing the structure is the azimuthal separation (sep) between the primary and secondary spiral arms. If you draw a circle within the disk and measure the angle between the two points where the primary and secondary arms cross it, thats sep.Azimuthal separation of the primary and secondary spiral arms, as a function of the planet-to-star mass ratio q. The different curves represent different disk aspect ratios. [Fung Dong, 2015]The authors find thatsep stays roughly constant for different radii, but its strongly dependent on the planets mass: for larger planets, sep increases. They discover that sep scales as a power of the planet mass for companions between Neptune mass and 16 Jupiter masses, orbiting around a solar-mass star. For larger, brown-dwarf-size companions, sep is a constant 180.If this new theory is confirmed, it could have very interesting implications for observations of protoplanetary disks: this would give us the ability to measure the mass of a planet in a disk without ever needing to directly observe the planet itself!Modeling ObservationsFung and Dong confirm their models by additionally running 3D simulations, which yield very similar outcomes. From these simulation results, they then synthesize scattered-light images similar to what we would expect to be able to observe with telescopes like the VLT, Gemini, or Subaru. The authors demonstrate that from these scattered-light images, they can correctly retrieve the planets mass to within 30%.Finally, as a proof-of-concept, the authors apply this modeling to an actual system: SAO 206462, a nearly face-on protoplanetary disk with an observed two-armed spiral within it. From the measured azimuthal separation of the two arms, the authors estimate that it contains a planet of about 6 Jupiter masses.CitationJeffrey Fung () and Ruobing Dong () 2015 ApJ 815 L21. doi:10.1088/2041-8205/815/2/L21

  18. Planet Masses from Disk Spirals

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-12-01

    Young, forming planets can generate immense spiral structures within their protoplanetary disks. A recent study has shown that observations of these spiral structures may allow astronomers to measure the mass of the planets that create them.Spirals From WavesSnapshots of the surface density of a protoplanetary disk in a 2D simulation, 3D simulation, and synthesized scattered-light image. Click for a closer look! [Fung Dong, 2015]Recent studies have shown that a single planet, if it is massive enough, can excite multiple density waves within a protoplanetary disk as it orbits. These density waves can then interfere to produce a multiple-armed spiral structure in the disk inside of the planets orbit a structure which can potentially be observed in scattered-light images of the disk.But what do these arms look like, and what factors determine their structure? In a recently published study, Jeffrey Fung and Ruobing Dong, two researchers at the University of California at Berkeley, have modeled the spiral arms in an effort to answer these questions.Arms Provide AnswersA useful parameter for describing the structure is the azimuthal separation (sep) between the primary and secondary spiral arms. If you draw a circle within the disk and measure the angle between the two points where the primary and secondary arms cross it, thats sep.Azimuthal separation of the primary and secondary spiral arms, as a function of the planet-to-star mass ratio q. The different curves represent different disk aspect ratios. [Fung Dong, 2015]The authors find thatsep stays roughly constant for different radii, but its strongly dependent on the planets mass: for larger planets, sep increases. They discover that sep scales as a power of the planet mass for companions between Neptune mass and 16 Jupiter masses, orbiting around a solar-mass star. For larger, brown-dwarf-size companions, sep is a constant 180.If this new theory is confirmed, it could have very interesting implications for observations of protoplanetary disks: this would give us the ability to measure the mass of a planet in a disk without ever needing to directly observe the planet itself!Modeling ObservationsFung and Dong confirm their models by additionally running 3D simulations, which yield very similar outcomes. From these simulation results, they then synthesize scattered-light images similar to what we would expect to be able to observe with telescopes like the VLT, Gemini, or Subaru. The authors demonstrate that from these scattered-light images, they can correctly retrieve the planets mass to within 30%.Finally, as a proof-of-concept, the authors apply this modeling to an actual system: SAO 206462, a nearly face-on protoplanetary disk with an observed two-armed spiral within it. From the measured azimuthal separation of the two arms, the authors estimate that it contains a planet of about 6 Jupiter masses.CitationJeffrey Fung () and Ruobing Dong () 2015 ApJ 815 L21. doi:10.1088/2041-8205/815/2/L21

  19. Tilting Saturn without tilting Jupiter: Constraints on giant planet migration

    E-print Network

    Brasser, R

    2015-01-01

    The migration and encounter histories of the giant planets in our Solar System can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin-orbit resonance mechanism can tilt Saturn's spin axis to the current obliquity if the product of the migration time scale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today's obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin-orbit resonance...

  20. DISCOVERING HABITABLE EARTHS, HOT JUPITERS, AND OTHER CLOSE PLANETS WITH MICROLENSING

    SciTech Connect

    Di Stefano, R.

    2012-06-20

    Searches for planets via gravitational lensing have focused on cases in which the projected separation, a, between planet and star is comparable to the Einstein radius, R{sub E} . This paper considers smaller orbital separations and demonstrates that evidence of close-orbit planets can be found in the low-magnification portion of the light curves generated by the central star. We develop a protocol for discovering hot Jupiters as well as Neptune-mass and Earth-mass planets in the stellar habitable zone. When planets are not discovered, our method can be used to quantify the probability that the lens star does not have planets within specified ranges of the orbital separation and mass ratio. Nearby close-orbit planets discovered by lensing can be subject to follow-up observations to study the newly discovered planets or to discover other planets orbiting the same star. Careful study of the low-magnification portions of lensing light curves should produce, in addition to the discoveries of close-orbit planets, definite detections of wide-orbit planets through the discovery of 'repeating' lensing events. We show that events exhibiting extremely high magnification can effectively be probed for planets in close, intermediate, and wide distance regimes simply by adding several-time-per-night monitoring in the low-magnification wings, possibly leading to gravitational lensing discoveries of multiple planets occupying a broad range of orbits, from close to wide, in a single planetary system.

  1. THE MASS OF KOI-94d AND A RELATION FOR PLANET RADIUS, MASS, AND INCIDENT FLUX

    E-print Network

    Weiss, Lauren M.

    We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or ...

  2. Tilting Saturn without Tilting Jupiter: Constraints on Giant Planet Migration

    NASA Astrophysics Data System (ADS)

    Brasser, R.; Lee, Man Hoi

    2015-11-01

    The migration and encounter histories of the giant planets in our solar system can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin–orbit resonance mechanism can tilt Saturn’s spin axis to the current obliquity if the product of the migration timescale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today’s obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin–orbit resonance crossing. Migration timescales sufficiently long to tilt Saturn generally suffice to tilt Jupiter more than is observed. The full N-body simulations tell a somewhat different story, with Jupiter generally being tilted as often as Saturn, but on average having a higher obliquity. The main obstacle is the final orbital spacing of the giant planets, coupled with the tail of Neptune’s migration. The resonant Nice case is barely able to simultaneously reproduce the orbital and spin properties of the giant planets, with a probability ? 0.15%. The loose five planet model is unable to match all our constraints (probability <0.08%). The compact five planet model has the highest chance of matching the orbital and obliquity constraints simultaneously (probability ?0.3%).

  3. The Solar Twin Planet Search. II. A Jupiter twin around a solar twin

    NASA Astrophysics Data System (ADS)

    Bedell, M.; Meléndez, J.; Bean, J. L.; Ramírez, I.; Asplund, M.; Alves-Brito, A.; Casagrande, L.; Dreizler, S.; Monroe, T.; Spina, L.; Tucci Maia, M.

    2015-09-01

    Context. With high-precision radial velocity surveys reaching a sufficiently long time baseline, the domain of long-period planet detections has recently opened up. The search for Jupiter-like planets is especially important if we wish to investigate the prevalence of solar system analogs, but their detection is complicated by the existence of stellar activity cycles on similar timescales. Radial velocity data with sufficiently long-term instrumental precision and robust methods of diagnosing activity are crucial to the detection of extrasolar Jupiters. Aims: Through our HARPS survey for planets around solar twin stars, we have identified a promising Jupiter twin candidate around the star HIP11915. We characterize this Keplerian signal and investigate its potential origins in stellar activity. Methods: We carry out a Markov chain Monte Carlo (MCMC) analysis of the radial velocity data. To examine the signal's origin, we employ a variety of statistical tests using activity diagnostics such as the Ca II H and K lines and line asymmetry tracers. Results: Our analysis indicates that HIP11915 hosts a Jupiter-mass planet with a 3800-day orbital period and low eccentricity. Although we cannot definitively rule out an activity cycle interpretation, we find that a planet interpretation is more likely based on a joint analysis of radial velocity and activity index data. Conclusions: The challenges of long-period radial velocity signals addressed in this paper are critical for the ongoing discovery of Jupiter-like exoplanets. If planetary in nature, the signal investigated here represents a very close analog to the solar system in terms of both Sun-like host star and Jupiter-like planet. Table 3 and Fig. 5 are available in electronic form at http://www.aanda.org

  4. The Mass Distribution Function of Planets

    E-print Network

    Malhotra, Renu

    2015-01-01

    The distribution of orbital period ratios of adjacent planets in extra-solar planetary systems discovered by the {\\it Kepler} space telescope exhibits a peak near $\\sim1.5$--$2$, a long tail of larger period ratios, and a steep drop-off in the number of systems with period ratios below $\\sim1.5$. We find from this data that the dimensionless orbital separations have an approximately log-normal distribution. The paucity of small orbital separations implies that the population of planets does not increase monotonically as planet mass decreases. Using Hill's criterion for the dynamical stability of two planets, we find an upper bound on planet masses such that the most common planet mass does not exceed $10^{-3.2}m_*$, or about two-thirds Jupiter mass for solar mass stars. We generalized Hill's criterion in a statistical way to estimate the planet mass distribution function from the distribution of orbital separations. We suggest that the planet mass function is peaked in logarithm of mass, and we estimate that ...

  5. Discovery of Low Mass Binary with Super Jupiter Companion

    NASA Astrophysics Data System (ADS)

    Anthes Rich, Evan; Wisniewski, John P.; Hashimoto, Jun; Brandt, Timothy; Kuzuhara, Masayuki; Tamura, Motohide

    2015-12-01

    Transit and radial velocity surveys have been prolific in detecting ~2000 confirmed planets to date. While few directly imaged planets have detected, such systems provide a unique scientific opportunity to probe exoplanets at larger angular separation, younger ages, and study their atmospheres. We present new L- and M-band AO observations, obtained with IRCS on Subaru, of a super Jupiter companion orbiting a cool dwarf. We show that the central object is likely a binary, thereby making this system the first likely directly imaged planetary mass companion surrounding a low mass binary system.

  6. I0-Jupiter system: A unique case of Moon-Planet interaction

    E-print Network

    A. Bhardwaj; M. Michael

    2002-09-04

    Io and Jupiter constitute a moon-planet system that is unique in our solar system. Io is the most volcanically active planetary body, while Jupiter is the first among the planets in terms of size, mass, magnetic field strength, spin rate, and volume of the magnetosphere. That Io is electrodynamically linked to Jupiter is known for nearly four decades from the radio emissions. Io influences Jupiter by supplying heavy ions to its magnetosphere, which dominates its energetic and dynamics. Jupiter influences Io by tidally heating its interior, which in turn drives the volcanic activity on Io. The role of Io and Jupiter in their mutual interaction and the nature of their coupling were first elaborated in greater detail by the two Voyagers flybys in 1979. Subsequent exploration of this system by ground-based and Earth-satellite-borne observatories and by the Galileo orbiter mission has improved our understanding of the highly complex electrodynamical interaction between Io and Jupiter many fold. A distinct feature of this interaction has been discovered in Jupiter's atmosphere as a auroral-like bright emission spot along with a comet-like tail in infrared (IR), ultraviolet (UV), and visible wavelengths at the foot of Io flux tube (IFT). The HST and Galileo and Cassini imagining experiments have observed emissions from the Io's atmosphere at UV and visible wavelengths, which could be produced by energetic electrons in IFT. In this paper an overview on these aspects of the Io-Jupiter system is presented, which by virtue of its electrodynamical coupling, has implications for the extra-solar planetary system and binary stars.

  7. Study of the Universe via Planets Phenomena: Jupiter contribution

    NASA Astrophysics Data System (ADS)

    Cocchiara, C. M.

    2011-10-01

    Since the beginning of the studies regarding Space, astronomers have been interested not only in what happens in the surroundings of our Planet, but they wanted to look further in order to understand the "reasons of the Universe". As such, the European Mars Express and Venus Express are still working giving back interesting results regarding Mars and Venus, and in the same way, Cassini is giving us results regarding Saturn. Of greatest importance is the study of Jupiter, and scientists are pushing towards a deeper knowledge of this planet. Jupiter and his system can give a large contribution to the study of our Solar System, especially because of its difference comparing to the other planets. As a matter of fact, contrary of what is always though, Jupiter teaches that not only the Sun is the key of our System, instead, many factors can be determined by different bodies, such as its moons. Moreover, the idea of moons, regarding Jupiter, should be considered under a different point of view.

  8. Simulated Photoevaporative Mass Loss from Hot Jupiters in 3D

    NASA Astrophysics Data System (ADS)

    Tripathi, Anjali; Kratter, Kaitlin M.; Murray-Clay, Ruth A.; Krumholz, Mark R.

    2015-08-01

    Ionizing stellar photons heat the upper regions of planetary atmospheres, driving atmospheric mass loss. Gas escaping from several hot, hydrogen-rich planets has been detected using UV and X-ray transmission spectroscopy. Because these planets are tidally locked, and thus asymmetrically irradiated, escaping gas is unlikely to be spherically symmetric. In this paper, we focus on the effects of asymmetric heating on local outflow structure. We use the Athena code for hydrodynamics to produce 3D simulations of hot Jupiter mass loss that jointly model wind launching and stellar heating via photoionization. Our fiducial planet is an inflated, hot Jupiter with radius {R}{{p}}=2.14{R}{Jup} and mass {M}{{p}}=0.53{M}{Jup}. We irradiate the initially neutral, atomic hydrogen atmosphere with 13.6 eV photons and compute the outflow’s ionization structure. There are clear asymmetries in the atmospheric outflow, including a neutral shadow on the planet’s nightside. Given an incident ionizing UV flux comparable to that of the Sun, we find a steady-state mass loss rate of ˜ 2× {10}10 g s-1. The total mass loss rate and the outflow substructure along the substellar ray show good agreement with earlier 1D models, for two different fluxes. Our 3D data cube can be used to generate the outflow’s extinction spectrum during transit. As a proof of concept, we find absorption of stellar Ly? at Doppler-shifted velocities of up to ±50 km s-1. Our work provides a starting point for further 3D models that can be used to predict observable signatures of hot Jupiter mass loss.

  9. Planet Masses And Radii - Theory Versus Transits

    NASA Astrophysics Data System (ADS)

    Wuchterl, Gunther

    2010-10-01

    Masses and radii are the primary observables to characterise exoplanets today. A self-consistent theoretical approach is presented that allows to calculate mass- and radii-distributions of exoplanet populations from basic physical principles and avoids the usual parametrisation of a multitude of processes. The theoretical strategy has two steps: 1) Calculate all planetary equilibria that satisfy hydrostatic and thermal equilibria with planetesimal accretion as energy source in arbitrary but gravitationally stable protoplanetary nebulae and 2) Calculate the quasi-hydrostatic evolution of the ensemble of planets found in step one, to the ages that are relevant for observations. The resulting theoretical distributions of planetary masses and radii are presented for stars of 0.4-2 MSun and orbital periods from 1-128 days. (1) Mass distributions are bi-modal with peaks near Jupiter's and Neptune's mass; the later usually containing more planets. The location of the peaks depends on host star mass and orbital radius. (2) The bi-modality of the mass-distributions is enhanced in the radii-distributions by the planetary evolution from the formation era into the present. (3) We discuss whether the observed planetary radii can be explained without the assumption of extra, non-standard energy sources. (4) A wide gap is found in the distribution of the transit signals between those of Pegasi-planets (Hot Jupiters) and the next population towards smaller radii: the Hot Neptunes and Super-Earths. A comparison with CoRoT, Kepler and ground-based results gives a first hint that the approach is useful to understand the observed planets and provides a concept for a basic-physics explanation of planetary mass. The approach does not a-priori assume a core and whether planets migrate or not and thus provides a general framework to discuss planet formation. It does allow to test the respective hypothesis of core-instability and a possible dominating role of orbital migration by comparison with observations.

  10. On the formation of terrestrial planets in hot-Jupiter systems

    E-print Network

    Martyn J. Fogg; Richard P. Nelson

    2006-10-11

    We present a series of calculations aimed at examining how an inner system of planetesimals/protoplanets, undergoing terrestrial planet formation, evolves under the influence of a giant planet undergoing inward type II migration through the region bounded between 5 - 0.1 AU. We find that > 60% of the solids disk survives by being scattered by the giant planet into external orbits. Planetesimals are scattered outward almost as efficiently as protoplanets, resulting in the regeneration of a solids disk where dynamical friction is strong and terrestrial planet formation is able to resume. A simulation extended for a few Myr after the migration of the giant planet halted at 0.1 AU, resulted in an apparently stable planet of ~ 2 Earth masses forming in the habitable zone. Migration-induced mixing of volatile-rich material from beyond the `snowline' into the inner disk regions means that terrestrial planets that form there are likely to be water-rich. We predict that hot--Jupiter systems are likely to harbor water-rich terrestrial planets in their habitable zones. These planets may be detected by future planet search missions.

  11. WASP-47: A Hot Jupiter System with Two Additional Planets Discovered by K2

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Vanderburg, Andrew; Adams, Fred C.; Rappaport, Saul A.; Schwengeler, Hans Martin

    2015-10-01

    Using new data from the K2 mission, we show that WASP-47, a previously known hot Jupiter host, also hosts two additional transiting planets: a Neptune-sized outer planet and a super-Earth inner companion. We measure planetary properties from the K2 light curve and detect transit timing variations (TTVs), confirming the planetary nature of the outer planet. We performed a large number of numerical simulations to study the dynamical stability of the system and to find the theoretically expected TTVs. The theoretically predicted TTVs are in good agreement with those observed, and we use the TTVs to determine the masses of two planets, and place a limit on the third. The WASP-47 planetary system is important because companion planets can both be inferred by TTVs and are also detected directly through transit observations. The depth of the hot Jupiter's transits make ground-based TTV measurements possible, and the brightness of the host star makes it amenable for precise radial velocity measurements. The system serves as a Rosetta Stone for understanding TTVs as a planet detection technique.

  12. Hot Jupiters with relatives: discovery of additional planets in orbit around WASP-41 and WASP-47

    E-print Network

    Neveu-VanMalle, M; Anderson, D R; Brown, D J A; Cameron, A Collier; Delrez, L; Díaz, R F; Gillon, M; Hellier, C; Jehin, E; Lister, T; Pepe, F; Rojo, P; Ségransan, D; Triaud, A H M J; Turner, O D; Udry, S

    2015-01-01

    We report the discovery of two additional planetary companions to WASP-41 and WASP-47. WASP-41 c is a planet of minimum mass 3.18 $\\pm$ 0.20 M$_{\\rm Jup}$, eccentricity 0.29 $\\pm$ 0.02 and orbiting in 421 $\\pm$ 2 days. WASP-47 c is a planet of minimum mass 1.24 $\\pm$ 0.22 M$_{\\rm Jup}$, eccentricity 0.13 $\\pm$ 0.10 and orbiting in 572 $\\pm$ 7 days. Unlike most of the planetary systems including a hot Jupiter, these two systems with a hot Jupiter have a long period planet located at only $\\sim$1 AU from their host star. WASP-41 is a rather young star known to be chromospherically active. To differentiate its magnetic cycle from the radial velocity effect due the second planet, we use the emission in the H$\\alpha$ line and find this indicator well suited to detect the stellar activity pattern and the magnetic cycle. The analysis of the Rossiter-McLaughlin effect induced by WASP-41 b suggests that the planet could be misaligned, though an aligned orbit cannot be excluded. WASP-47 has recently been found to host ...

  13. Alternate multiple-outer-planet missions using a Saturn-Jupiter flyby sequence

    NASA Technical Reports Server (NTRS)

    Young, J. W.; Hannah, M. E.

    1973-01-01

    A study has been made of a method for providing more frequent launch opportunities for multiple-planet Grand Tour type missions to the outer solar system. A Saturn-Jupiter flyby sequence was used in the analysis to initiate the mission instead of the normal Jupiter-Saturn sequence. The Saturn-first approach is shown to yield several new launch opportunities following the 1980 cutoff date for Jupiter-first missions. Results are given for various two-planet, three-planet, and four-planet Jupiter-first and Saturn-first missions. A unique five-planet Saturn-first mission and a Saturn-Jupiter flyby which returns to earth are also discussed. Mission performance is evaluated for each flyby technique by comparing Saturn-first and Jupiter-first missions with respect to launch energy requirements, available launch windows, planetary encounter conditions, and total mission times.

  14. N-body simulations of terrestrial planet formation under the influence of a hot Jupiter

    SciTech Connect

    Ogihara, Masahiro; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro E-mail: ogihara@nagoya-u.jp

    2014-06-01

    We investigate the formation of multiple-planet systems in the presence of a hot Jupiter (HJ) using extended N-body simulations that are performed simultaneously with semianalytic calculations. Our primary aims are to describe the planet formation process starting from planetesimals using high-resolution simulations, and to examine the dependences of the architecture of planetary systems on input parameters (e.g., disk mass, disk viscosity). We observe that protoplanets that arise from oligarchic growth and undergo type I migration stop migrating when they join a chain of resonant planets outside the orbit of an HJ. The formation of a resonant chain is almost independent of our model parameters, and is thus a robust process. At the end of our simulations, several terrestrial planets remain at around 0.1 AU. The formed planets are not equal mass; the largest planet constitutes more than 50% of the total mass in the close-in region, which is also less dependent on parameters. In the previous work of this paper, we have found a new physical mechanism of induced migration of the HJ, which is called a crowding-out. If the HJ opens up a wide gap in the disk (e.g., owing to low disk viscosity), crowding-out becomes less efficient and the HJ remains. We also discuss angular momentum transfer between the planets and disk.

  15. An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b.

    PubMed

    Hellier, Coel; Anderson, D R; Cameron, A Collier; Gillon, M; Hebb, L; Maxted, P F L; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Wilson, D M; Bentley, S J; Enoch, B; Horne, K; Irwin, J; Lister, T A; Mayor, M; Parley, N; Pepe, F; Pollacco, D L; Segransan, D; Udry, S; Wheatley, P J

    2009-08-27

    The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M(Jup)), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10(6), as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System. PMID:19713926

  16. WASP-47: A Hot Jupiter System with Two Additional Planets Discovered by K2

    E-print Network

    Becker, Juliette C; Adams, Fred C; Rappaport, Saul A; Schwengeler, Hans Martin

    2015-01-01

    Using new data from the K2 mission, we show that WASP-47, a previously known hot Jupiter host, also hosts two additional transiting planets: a Neptune-sized outer planet and a super-Earth inner companion. We measure planetary properties from the K2 light curve and detect transit timing variations, confirming the planetary nature of the outer planet. We performed a large number of numerical simulations to study the dynamical stability of the system and to find the theoretically expected transit timing variations (TTVs). The theoretically predicted TTVs are in good agreement with those observed, and we use the TTVs to determine the masses of two planets, and place a limit on the third. The WASP-47 planetary system is important because companion planets can both be inferred by TTVs and are also detected directly through transit observations. The depth of the hot Jupiter's transits make ground-based TTV measurements possible, and the brightness of the host star makes it amenable for precise radial velocity measur...

  17. The Dynamics of the WASP-47 Planetary System: A Hot Jupiter, Two Additional Planets, and Observable Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.; Becker, Juliette C.; Vanderburg, Andrew; Rappaport, Saul; Schwengeler, Hans Martin

    2015-12-01

    New data from the K2 mission indicate that WASP-47, a previously known Hot Jupiter host, also hosts two additional transiting planets: a Neptune-sized outer planet and a super-Earth inner companion. The measured period ratios and size ratios for these planets are unusual (extreme) for Hot Jupiter systems. We measure the planetary properties from the K2 light curve and detect transit timing variations, thereby confirming the planetary nature of the outer planet. We performed a large ensemble of numerical simulations to study the dynamical stability of the system and to find the theoretically expected transit timing variations (TTVs). The system is stable provided that the orbital eccentricities are small. The theoretically predicted TTVs are in good agreement with those observed, and we use the TTVs to determine the masses of two planets, and place a limit on the third. The WASP-47 planetary system is important because the companion planets can both be inferred by TTVs and are also detected directly through transit observations. The depth of the Hot Jupiter’s transits make ground-based TTV measurements possible, and the brightness of the host star makes it amenable for precise radial velocity measurements. The system thus serves as a Rosetta Stone for understanding TTVs as a planet detection technique. Moreover, this compact set of planets in nearly circular, coplanar orbits demonstrates that at least a subset of Jupiter-size planets can migrate in close to their host star in a dynamically quiet manner. As final curiosity, WASP-47 hosts one of few extrasolar planetary systems that can observe Earth in transit.

  18. Inferring Planet Mass from Spiral Structures in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Fung, Jeffrey; Dong, Ruobing

    2015-12-01

    Recent observations of protoplanetary disk have reported spiral structures that are potential signatures of embedded planets, and modeling efforts have shown that a single planet can excite multiple spiral arms, in contrast to conventional disk–planet interaction theory. Using two and three-dimensional hydrodynamics simulations to perform a systematic parameter survey, we confirm the existence of multiple spiral arms in disks with a single planet, and discover a scaling relation between the azimuthal separation of the primary and secondary arm, {? }{{sep}}, and the planet-to-star mass ratio q: {? }{{sep}}=102^\\circ {(q/0.001)}0.2 for companions between Neptune mass and 16 Jupiter masses around a 1 solar mass star, and {? }{{sep}}=180^\\circ for brown dwarf mass companions. This relation is independent of the disk’s temperature, and can be used to infer a planet’s mass to within an accuracy of about 30% given only the morphology of a face-on disk. Combining hydrodynamics and Monte-Carlo radiative transfer calculations, we verify that our numerical measurements of {? }{{sep}} are accurate representations of what would be measured in near-infrared scattered light images, such as those expected to be taken by Gemini/GPI, Very Large Telescope/SPHERE, or Subaru/SCExAO in the future. Finally, we are able to infer, using our scaling relation, that the planet responsible for the spiral structure in SAO 206462 has a mass of about 6 Jupiter masses.

  19. THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED

    SciTech Connect

    Miller, Neil; Fortney, Jonathan J.

    2011-08-01

    We investigate a population of transiting planets that receive relatively modest stellar insolation, indicating equilibrium temperatures <1000 K, and for which the heating mechanism that inflates hot Jupiters does not appear to be significantly active. We use structural evolution models to infer the amount of heavy elements within each of these planets. There is a correlation between the stellar metallicity and the mass of heavy elements in its transiting planet(s). It appears that all giant planets possess a minimum of {approx}10-15 Earth masses of heavy elements, with planets around metal-rich stars having larger heavy-element masses. There is also an inverse relationship between the mass of the planet and the metal enrichment (Z{sub pl}/Z{sub star}), which appears to have little dependency on the metallicity of the star. Saturn- and Jupiter-like enrichments above solar composition are a hallmark of all the gas giants in the sample, even planets of several Jupiter masses. These relationships provide an important constraint on planet formation and suggest large amounts of heavy elements within planetary H/He envelopes. We suggest that the observed correlation can soon also be applied to inflated planets, such that the interior heavy-element abundance of these planets could be estimated, yielding better constraints on their interior energy sources. We point to future directions for planetary population synthesis models and suggest future correlations. This appears to be the first evidence that extrasolar giant planets, as a class, are enhanced in heavy elements.

  20. Nonuniform viscosity in the solar nebula and large masses of Jupiter and Saturn

    E-print Network

    Liping Jin

    2008-05-06

    I report a novel theory that nonuniform viscous frictional force in the solar nebula accounts for the largest mass of Jupiter and Saturn and their largest amount of H and He among the planets, two outstanding facts that are unsolved puzzles in our understanding of origin of the Solar System. It is shown that the nebula model of uniform viscosity does not match the present planet masses. By studying current known viscosity mechanisms, I show that viscosity is more efficient in the inner region inside Mercury and the outer region outside Jupiter-Saturn than the intermediate region. The more efficient viscosity drives faster radial inflow of material during the nebula evolution. Because the inflow in the outer region is faster than the intermediate region, the material tends to accumulate in Jupiter-Saturn region which is between the outer and intermediate region. It is demonstrated that the gas trapping time of Jovian planets is longer than the inflow time in the outer region. Therefore the gas already flows to Jupiter-Saturn region before Uranus and Neptune can capture significant gas. But the inflow in the Jupiter-Saturn region is so slow that they can capture large amount of gas before the gas can flow further inward. Hence they have larger masses with larger H and He content than Uranus and Neptune. I also extend the discussion to the masses of the terrestrial planets, especially low mass of Mercury. The advantages of this theory are discussed.

  1. XO-5b: A Transiting Jupiter-sized Planet with a 4 day Period

    NASA Astrophysics Data System (ADS)

    Burke, Christopher J.; McCullough, P. R.; Valenti, Jeff A.; Long, Doug; Johns-Krull, Christopher M.; Machalek, P.; Janes, Kenneth A.; Taylor, B.; Fleenor, Michael L.; Foote, C. N.; Gary, Bruce L.; García-Melendo, Enrique; Gregorio, J.; Vanmunster, T.

    2008-10-01

    The star XO-5 (GSC 02959-00729, V=12.1, G8 V) hosts a Jupiter-sized, Rp=1.15+/-0.12 RJ, transiting extrasolar planet, XO-5b, with an orbital period of 4.2 days. The planet's mass, Mp=1.15+/-0.08 MJ, and surface gravity, gp=22+/-5 m s-2, are large for its orbital period compared to most other transiting planets. However, the deviation from the Mp-P relationship for XO-5b is not as large as for GJ 436b, HAT-P-2b, and XO-3b. By coincidence, XO-5 overlies the extreme H I plume that emanates from the interacting galaxy pair NGC 2444/NGC 2445 (Arp 143).

  2. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. II. A SATURN-JUPITER CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-08-10

    We carry out a series of high-resolution (1024 x 1024) hydrodynamic simulations to investigate the orbital evolution of a Saturn-Jupiter pair embedded in a gaseous disk. This work extends the results of our previous work by exploring a different orbital configuration-Jupiter lies outside Saturn (q < 1, where q {identical_to} M{sub i} /M{sub o} is the mass ratio of the inner planet and the outer one). We focus on the effects of different initial separations (d) between the two planets and the various surface density profiles of the disk, where {sigma} {proportional_to} r {sup -}{alpha}. We also compare the results of different orbital configurations of the planet pair. Our results show that (1) when the initial separation is relatively large (d>d {sub iLr}, where d {sub iLr} is the distance between Jupiter and its first inner Lindblad resonance), the two planets undergo divergent migration. However, the inward migration of Saturn could be halted when Jupiter compresses the inner disk in which Saturn is embedded. (2) Convergent migration occurs when the initial separation is smaller (d < d {sub iLr}) and the density slope of the disk is nearly flat ({alpha} < 1/2). Saturn is then forced by Jupiter to migrate inward where the two planets are trapped into mean motion resonances (MMRs), and Saturn may get very close to the central star. (3) In the case of q < 1, the eccentricity of Saturn could be excited to a very high value (e{sub S} {approx} 0.4-0.5) by the MMRs and the system could maintain stability. These results explain the formation of MMRs in the exoplanet systems where the outer planet is more massive than the inner one. It also helps us to understand the origin of the 'hot Jupiter/Saturn' with a highly eccentric orbit.

  3. Exploring the Relationship Between Planet Mass and Atmospheric Metallicity

    NASA Astrophysics Data System (ADS)

    Knutson, Heather; Deming, Drake; Desert, Jean-Michel; Fortney, Jonathan; Morley, Caroline; Moses, Julianne; Kammer, Joshua; Line, Michael

    2013-10-01

    Observations of transiting planets provide an invaluable window into the processes of planet formation and evolution. By measuring the masses and radii of these planets, we can calculate their average densities and constrain their bulk compositions, which presumably vary depending on their formation locations and accretionary histories. Results from large surveys such as Kepler indicate that the average densities of planets tend to increase with decreasing mass, suggesting that low-mass planets have comparatively large rocky or icy cores. In this proposal we will test a fundamental finding of planetary science over the past few decades: the correlation between core mass fraction and atmospheric metallicity. In our own solar system, Neptune and Uranus have both a larger percentage of their masses tied up in solid cores and more metal-rich atmospheres as compared to Jupiter and Saturn. However, with a sample size of just four planets it is difficult to know whether or not this relation holds for all exoplanets, or just for systems that meet particular conditions. Our program focuses on secondary eclipse observations of cool planets, where the relative abundances of methane and CO provide a sensitive tracer of atmospheric metallicity. We select a sample of planets with masses ranging from sub-Neptune to super-Jupiter sizes and temperatures cooler than 1100 K; these systems offer the first opportunity to confront this fundamental question prior to the launch of JWST.

  4. Giant Planets on Resonant Orbits: The Effect of Mass Growth

    NASA Astrophysics Data System (ADS)

    Marzari, Francesco; D'Angelo, Gennaro

    Two giant planets that undergo convergent migration, driven by tidal interactions with their gaseous disk, may become locked into a mean motion resonance (MMR). For planet masses similar to those of Jupiter (the internal planet) and Saturn and for typical post-formation (i.e., after planets have formed) disk conditions, capture occurs in the 2:1 MMR (D'Angelo and Marzari 2012). Capture in the 3:2 MMR may occur if the post-formation gas density around the planet locations is large enough (e.g., > ~2000 g/cm2 at ~1AU). This scenario, however, neglects the effects of ongoing gas accretion on the planets, which may be significant especially at large disk gas densities. In fact, recent work (Gressel et al. 2013; Keith and Wardle 2014), suggests that even if turbulence in the proximity of the planets is caused by MRI, gas accretion may still be vigorous. In particular, the MHD calculations of Gressel et al. (2013) resulted in accretion rates compatible to those derived from hydrodynamical calculations (D'Angelo et al. 2003; Bate et al. 2003). In order to address this issue, we perform hydrodynamical models of the evolution of a pair of planets that interact with each other and with the disk. The planets are initially locked in the 2:1 or 3:2 MMR. Gas accretion depends on the local disk mass. The large gas densities required for capture in the 3:2 MMR rapidly change the planet masses and mass ratio. Ensuing planet-planet interactions affect orbital eccentricities, leading to scattering and ejection episodes. The conditions required by 2:1 MMR locking can also produce a significant mass growth, if the local disk is sufficiently massive. For planets orbiting in the 1 AU region, however, the resonant configuration appears stable up to several Jupiter's masses.

  5. The formation and habitability of terrestrial planets in the presence of hot jupiters

    E-print Network

    Sean N. Raymond; Thomas Quinn; Jonathan I. Lunine

    2004-07-29

    `Hot jupiters,' giant planets with orbits very close to their parent stars, are thought to form farther away and migrate inward via interactions with a massive gas disk. If a giant planet forms and migrates quickly, the planetesimal population has time to re-generate in the lifetime of the disk and terrestrial planets may form (Armitage 2003). We present results of simulations of terrestrial planet formation in the presence of hot jupiters, broadly defined as having orbital radii planets similar to those in the Solar System can form around stars with hot jupiters, and can have water contents equal to or higher than the Earth's. For small orbital radii of hot jupiters (e.g. 0.15, 0.25 AU) potentially habitable planets can form, but for semi-major axes of 0.5 AU or greater their formation is suppressed. We show that the presence of an outer giant planet such as Jupiter does not enhance the water content of the terrestrial planets, but rather decreases their formation and water delivery timescales. We speculate that asteroid belts may exist interior to the terrestrial planets in systems with hot jupiters.

  6. AN INTERPRETATION OF THE ORBITAL PERIOD DIFFERENCE BETWEEN HOT JUPITERS AND GIANT PLANETS ON LONG-PERIOD ORBITS

    SciTech Connect

    Jin Liping

    2010-09-10

    It is believed that a hot Jupiter (giant planet with a short period less than 10 days) forms in the outer region of a protoplanetary disk, then migrates inward to an orbit with a short period around 3 days, and stops there by a final stopping mechanism. The prominent problem is why hot Jupiters migrate inward to short-period orbits, while other extrasolar giant planets and Jovian planets in our solar system exist on long-period orbits. Here we show that this difference in orbital periods is caused by two populations of protoplanetary disks. One population experiences gravitational instability during some periods of their lifetime (GI disks), while the other does not (No-GI disks). In GI disks, planets can quickly migrate inward to short-period orbits to become hot Jupiters. In No-GI disks, the migration is so slow that planets can exist on long-period orbits. Protoplanetary disks are classified into the two populations because of the differences in properties of molecular cloud cores, from which disks from. We specifically compare our theory with observations. Our theory is supported by observations of extrasolar planets. We analyze the current status of our solar system and find that our solar nebula belongs to the population with a low migration rate. This is consistent with the observation that Jupiter and Saturn are indeed on long-period orbits. Our results further suggest that, in the future observations, a hot Jupiter cannot be found around a star with mass below a critical mass (0.14-0.28 M {sub sun}).

  7. Helping students understand planet categories using "sensing" personification: Jupiter as want-to-be star, Earth as want-to-be Jupiter, etc.

    NASA Astrophysics Data System (ADS)

    Tabor-Morris, Anne

    2015-11-01

    Students often, in learning about the classification of planets, consider the planets to be in strict categories (such as gas giants and terrestrial planets) and assume that these categories are drastically different in nature. This is not the case. Small objects such as asteroids have a weak gravitational pull such that they cannot hold an atmosphere, while terrestrial planets are capable of holding a gaseous (often transparent) atmosphere according to their larger mass. However, asteroids and terrestrial planets are very similar in composition (though not necessarily in homogeneity due to varying presence of collisional heating during formation). Meanwhile, gas giant planets (also often referred to as Jovian planets) such as Jupiter have been theorized to contain super-sized rocky terrestrial-like planets interior to their dense cloud covering. Hence, due then to their similar natures, the categorization of the terrestrial and gas giant planets is made not due to fundamental differences in the nature of the planets, a concept often ill-understood by students. Examining this further, the gas giants are planets whose masses, and hence gravitational ability to condense their gases, especially those close to their core, is less than those of stars wherein thermonuclear fusion initiates. This implies that stars also have terrestrial cores (albeit likely extremely densely packed), but the gaseous environments of hydrogen are dense enough to start and sustain this process of thermonuclear fusion. It is proposed here that seeing planets as fundamentally related to each other in composition though differing in size allows students to better understand the variety of planet types AND describing these as want-to-be (or wanna-be) in terms of ranking and according to a “sensing” personification that eschews anthropomorphism, animism, or teleology [see A. E. Tabor-Morris, “Thinking in terms of sensors: personification of self as an object in physics problem solving” Physics Education, 50.2 (Feb 2015) 203-209] to assist in putting this into perspective for students.

  8. A Low Mass for Mars from Jupiter's Early Gas-Driven Migration

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin J.; Morbidelli, Alessandro; Raymond, Sean N.; O'Brien, David P.; Mandell, Avi M.

    2011-01-01

    Jupiter and Saturn formed in a few million years from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only approximately 100,000 years. Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 AU is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 AU, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 AU; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 AU and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.

  9. A low mass for Mars from Jupiter's early gas-driven migration.

    PubMed

    Walsh, Kevin J; Morbidelli, Alessandro; Raymond, Sean N; O'Brien, David P; Mandell, Avi M

    2011-07-14

    Jupiter and Saturn formed in a few million years (ref. 1) from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only ?100,000 years (ref. 2). Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later, and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 au is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 au, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 au; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 au and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought. PMID:21642961

  10. ON THE FUNDAMENTAL MASS-PERIOD FUNCTIONS OF EXTRASOLAR PLANETS

    SciTech Connect

    Jiang, I.-G.; Yeh, L.-C.; Chang, Y.-C.; Hung, W.-L.

    2010-01-01

    Employing a catalog of 175 extrasolar planets (exoplanets) detected by the Doppler-shift method, we constructed the independent and coupled mass-period functions. It is the first time in this field that the selection effect is considered in the coupled mass-period functions. Our results are consistent with those of Tabachnik and Tremaine in 2002, with the major difference that we obtain a flatter mass function but a steeper period function. Moreover, our coupled mass-period functions show that about 2.5% of stars would have a planet with mass between Earth Mass and Neptune Mass, and about 3% of stars would have a planet with mass between Neptune Mass and Jupiter Mass.

  11. Jupiter and Planet Earth. [planetary and biological evolution and natural satellites

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included.

  12. Orbital Stability of Multi-Planet Systems: Behavior at High Masses

    NASA Astrophysics Data System (ADS)

    Morrison, Sarah J.; Kratter, Kaitlin M.

    2015-12-01

    We explore the relationships between planet separation, mass, and stability timescale in high mass multi-planet systems containing planet masses and multiplicities relevant for planetary systems detectable via direct imaging. Extrapolating empirically derived relationships between planet mass, separation, and stability timescale derived from lower mass planetary systems misestimate the stability timescales for higher mass planetary systems by more than an order of magnitude at close separations near the two body Hill stability limit. We also find that characterizing critical separations in terms of period ratio produces a linear relationship between log-timescale and separation with the same slope for planet-star mass ratios comparable to or exceeding Jupiter’s, but this slope steepens for lower mass planetary systems. We discuss possible mechanisms for instability that result in this behavior including perturbing adjacent planet pairs into an overlap regime between 1st and sometimes 2nd order mean motion resonances.

  13. Comparison Between Extrasolar Planets and Low-Mass Secondaries

    E-print Network

    T. Mazeh; S. Zucker

    2000-08-04

    This paper compares the statistical features of the sample of discovered extrasolar planets with those of the secondaries in nearby spectroscopic binaries, in order to enable us to distinguish between the two populations. Based on 32 planet candidates discovered until March 2000, we find that their eccentricity and period distribution are surprisingly similar to those of the binary population, while their mass distribution is remarkably different. The mass distributions definitely support the idea of two distinct populations, suggesting the planet candidates are indeed extrasolar planets. The transition between the two populations probably occurs at 10--30 Jupiter masses. We point out a possible negative correlation between the orbital period of the planets and the metallicity of their parent stars, which holds only for periods less than about 100 days. These short-period systems are characterized by circular or almost circular orbits.

  14. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (mass) using a combination of analytic and numerical calculations, and I will show that all low-mass planets obey a kind of universal mass-radius relationship: an expansion whose first term is M approx. R(sup 3).

  15. A common mass scaling for satellite systems of gaseous planets.

    PubMed

    Canup, Robin M; Ward, William R

    2006-06-15

    The Solar System's outer planets that contain hydrogen gas all host systems of multiple moons, which notably each contain a similar fraction of their respective planet's mass (approximately 10(-4)). This mass fraction is two to three orders of magnitude smaller than that of the largest satellites of the solid planets (such as the Earth's Moon), and its common value for gas planets has been puzzling. Here we model satellite growth and loss as a forming giant planet accumulates gas and rock-ice solids from solar orbit. We find that the mass fraction of its satellite system is regulated to approximately 10(-4) by a balance of two competing processes: the supply of inflowing material to the satellites, and satellite loss through orbital decay driven by the gas. We show that the overall properties of the satellite systems of Jupiter, Saturn and Uranus arise naturally, and suggest that similar processes could limit the largest moons of extrasolar Jupiter-mass planets to Moon-to-Mars size. PMID:16778883

  16. The anglo-australian planet search. XXIII. Two new Jupiter analogs

    SciTech Connect

    Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.; Salter, G. S.; Bailey, J.; Wright, D.; Butler, R. P.; Jones, H. R. A.; Tuomi, Mikko; Carter, B. D.; Koch, F. Elliott; O'Toole, S. J.

    2014-03-10

    We report the discovery of two long-period giant planets from the Anglo-Australian Planet Search. HD 154857c is in a multiple-planet system, while HD 114613b appears to be solitary. HD 114613b has an orbital period P = 10.5 yr, and a minimum mass msin i of 0.48 M {sub Jup}; HD 154857c has P = 9.5 yr and msin i = 2.6 M {sub Jup}. These new data confirm the planetary nature of the previously unconstrained long-period object in the HD 154857 system. We have performed detailed dynamical stability simulations which show that the HD 154857 two-planet system is stable on timescales of at least 10{sup 8} yr. These results highlight the continued importance of 'legacy' surveys with long observational baselines; these ongoing campaigns are critical for determining the population of Jupiter analogs, and hence of those planetary systems with architectures most like our own solar system.

  17. The Now Frontier. Pioneer to Jupiter. Man Links Earth and Planets. Issue No. 1-5.

    ERIC Educational Resources Information Center

    1973

    This packet of space science instructional materials includes five issues related to the planet Jupiter. Each issue presents factual material about the planet, diagramatic representations of its movements and positions relative to bright stars or the earth, actual photographs and/or tables of data collected relevant to Pioneer 10, the spacecraft…

  18. A SHORT-PERIOD CENSOR OF SUB-JUPITER MASS EXOPLANETS WITH LOW DENSITY

    SciTech Connect

    Szabo, Gy. M.; Kiss, L. L.

    2011-02-01

    Despite the existence of many short-period hot Jupiters, there is not one hot Neptune with an orbital period less than 2.5 days. Here, we discuss a cluster analysis of the currently known 106 transiting exoplanets to investigate a possible explanation for this observation. We find two distinct clusters in the mass-density space, one with hot Jupiters with a wide range of orbital periods (0.8-114 days) and a narrow range of planet radii (1.2 {+-} 0.2 R{sub J} ) and another one with a mixture of super-Earths, hot Neptunes, and hot Jupiters, exhibiting a surprisingly narrow period distribution (3.7 {+-} 0.8 days). These two clusters follow strikingly different distributions in the period-radius parameter plane. The branch of sub-Jupiter mass exoplanets is censored by the orbital period at the large-radius end: no planets with mass between 0.02 and 0.8 M{sub J} or with radius between 0.25 and 1.0 R{sub J} are known with P{sub orb} < 2.5 days. This clustering is not predicted by current theories of planet formation and evolution, which we also review briefly.

  19. Direct Exoplanet Imaging with JWST NIRCam: Low-Mass Stars, Low-Mass Planets, and Critical Constraints on Planet Formation

    NASA Astrophysics Data System (ADS)

    Schlieder, Joshua E.; Meyer, Michael; Reggiani, Maddalena; Quanz, Sascha; Beichman, Charles A.; Greene, Thomas P.; Burrows, Adam Seth

    2016-01-01

    As next generation exoplanet imagers are making their first discoveries, the largest population of stars in the Galaxy, the M dwarfs, are largely unaccounted for in their surveys. However, RV trends and micro lensing have revealed that M dwarfs host a substantial population of Neptune to Jupiter mass planets between ~1-10 AU. The unprecedented sensitivity of NIRCam on the JWST provides direct access to this population of gas-giants. A NIRCam 3 - 5 ?m survey for such planets will place critical constraints on planet formation by: 1) measuring the luminosities of young, sub-Jupiter mass planets, 2) providing constraints on the peak in the companion surface density vs. separation distribution, and 3) measuring the frequency of ?Jupiter mass giants in the outskirts of these systems (>10 AU). We have carefully constructed a sample of nearby, young, late-type stars, performed NIRCam survey simulations, and will report on the expected yield and advantages of JWST compared to current ground based capabilities.

  20. Total mass of the Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Vinogradova, T. A.; Chernetenko, Yu. A.

    2015-12-01

    The total mass of the Jupiter Trojans is estimated at (0.30 ± 0.19) × 10-10 M Sun using all available physical characteristics of these asteroids. The mass of asteroids in the L4 swarm ((0.19 ± 0.11) × 10-10 M Sun) is higher than that in the L5 swarm ((0.11 ± 0.07) × 10-10 M Sun) by a factor of 1.7. The obtained estimates include the hidden mass of asteroids that are not discovered yet. This hidden component constitutes 7% of the total mass. The number of Trojans with diameters larger than 1 km is estimated at 6 × 105. The number of such asteroids at the L4 Lagrangian point ( N L4 = 4 × 105) is two times higher than that at the L5 Lagrangian point ( N L5 = 2 × 105). It is found that the N L4/ N L5 ratio is increased at smaller asteroid sizes or higher absolute magnitudes H. This ratio equals just 1.3 for asteroids with H <11m (i.e., asteroids with diameters D > 30 km). The effect of gravitational perturbations from Trojans on the motion of Hildian asteroids and centaurs is evaluated. This effect turned out to be at the limit of accuracy of modern observations.

  1. Mass-loss evolution of close-in exoplanets: Evaporation of hot Jupiters and the effect on population

    SciTech Connect

    Kurokawa, H.; Nakamoto, T.

    2014-03-01

    During their evolution, short-period exoplanets may lose envelope mass through atmospheric escape owing to intense X-ray and extreme ultraviolet (XUV) radiation from their host stars. Roche-lobe overflow induced by orbital evolution or intense atmospheric escape can also contribute to mass loss. To study the effects of mass loss on inner planet populations, we calculate the evolution of hot Jupiters considering mass loss of their envelopes and thermal contraction. Mass loss is assumed to occur through XUV-driven atmospheric escape and the following Roche-lobe overflow. The runaway effect of mass loss results in a dichotomy of populations: hot Jupiters that retain their envelopes and super Earths whose envelopes are completely lost. Evolution primarily depends on the core masses of planets and only slightly on migration history. In hot Jupiters with small cores (? 10 Earth masses), runaway atmospheric escape followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in both mass and radius distributions of planetary populations. Comparing our results with formation scenarios and observed exoplanets populations, we propose that populations of closely orbiting exoplanets are formed by capturing planets at/inside the inner edges of protoplanetary disks and subsequent evaporation of sub-Jupiters.

  2. WASP-41b: A Transiting Hot Jupiter Planet Orbiting a Magnetically Active G8V Star

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A.; Hellier, C.; Queloz, D.; Smalley, B.; Street, R. A.; Triaud, A. H. M. J.; West, R. G.; Gillon, M.; Lister, T. A.; Pepe, F.; Pollacco, D.; Ségransan, D.; Smith, A. M. S.; Udry, S.

    2011-05-01

    We report the discovery of a transiting planet with an orbital period of 3.05 days orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8 V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08±0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the Ca ii H and K ines and photometric variability with a period of 18.4 days and an amplitude of about 1%. We use a new method to show quantitatively that this periodic signal has a low false-alarm probability. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8 Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.92±0.06 M, 1.20±0.06 R). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars.

  3. Hot Jupiter Breezes: Time-dependent Outflows from Extrasolar Planets

    E-print Network

    Owen, James E

    2015-01-01

    We explore the dynamics of magnetically controlled outflows from Hot Jupiters, where these flows are driven by UV heating from the central star. In these systems, some of the open field lines do not allow the flow to pass smoothly through the sonic point, so that steady-state solutions do not exist in general. This paper focuses on this type of magnetic field configuration, where the resulting flow becomes manifestly time-dependent. We consider the case of both steady heating and time-variable heating, and find the time scales for the corresponding time variations of the outflow. Because the flow cannot pass through the sonic transition, it remains subsonic and leads to so-called breeze solutions. One manifestation of the time variability is that the flow samples a collection of different breeze solutions over time, and the mass outflow rate varies in quasi-periodic fashion. Because the flow is subsonic, information can propagate inward from the outer boundary, which determines, in part, the time scale of the...

  4. CROWDING-OUT OF GIANTS BY DWARFS: AN ORIGIN FOR THE LACK OF COMPANION PLANETS IN HOT JUPITER SYSTEMS

    SciTech Connect

    Ogihara, Masahiro; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi

    2013-11-20

    We investigate the formation of close-in terrestrial planets from planetary embryos under the influence of a hot Jupiter (HJ) using gravitational N-body simulations that include gravitational interactions between the gas disk and the terrestrial planet (e.g., type I migration). Our simulations show that several terrestrial planets efficiently form outside the orbit of the HJ, making a chain of planets, and all of them gravitationally interact directly or indirectly with the HJ through resonance, which leads to inward migration of the HJ. We call this mechanism of induced migration of the HJ ''crowding-out''. The HJ is eventually lost through collision with the central star, and only several terrestrial planets remain. We also find that the efficiency of the crowding-out effect depends on the model parameters; for example, the heavier the disk is, the more efficient the crowding-out is. When planet formation occurs in a massive disk, the HJ can be lost to the central star and is never observed. On the other hand, for a less massive disk, the HJ and terrestrial planets can coexist; however, the companion planets may be below the detection limit of current observations. In both cases, systems with a HJ and terrestrial planets have little chance of detection. Therefore, our model naturally explains the lack of companion planets in HJ systems regardless of the disk mass. In effect, our model provides a theoretical prediction for future observations; additional planets can be discovered just outside the HJ, and their masses should generally be small.

  5. Jupiter Observation Campaign - Citizen Science At The Outer Planets: A Progress Report

    NASA Astrophysics Data System (ADS)

    Houston Jones, J.; Dyches, P.

    2012-12-01

    Amateur astronomers and astrophotographers diligently image Mars, Saturn and Jupiter in amazing detail. They often capture first views of storms on Saturn, impacts on Jupiter and changes in the planet's atmospheres. Many of the worldwide cadre of imagers share their images with each other and with planetary scientists. This new Jupiter focused citizen science program seeks to collect images and sort them into categories useful to scientists. In doing so, it provides a larger population of amateur astronomers with the opportunity to contribute their observations to NASA's JUNO Mission.

  6. New Concept for Internal Heat Production in Hot Jupiter Exo-Planets

    E-print Network

    J. Marvin Herndon

    2006-12-20

    Discovery of hot Jupiter exo-planets, those with anomalously inflated size and low density relative to Jupiter, has evoked much discussion as to possible sources of internal heat production. But to date, no explanations have come forth that are generally applicable. The explanations advanced typically involve presumed tidal dissipation and/or converted incident stellar radiation. The present, brief communication suggests a novel interfacial nuclear fission-fusion source of internal heat production for hot Jupiters that has been overlooked by theoreticians and which has potentially general applicability.

  7. Study of spin-scan imaging for outer planets missions. [imaging techniques for Jupiter orbiter missions

    NASA Technical Reports Server (NTRS)

    Russell, E. E.; Chandos, R. A.; Kodak, J. C.; Pellicori, S. F.; Tomasko, M. G.

    1974-01-01

    The constraints that are imposed on the Outer Planet Missions (OPM) imager design are of critical importance. Imager system modeling analyses define important parameters and systematic means for trade-offs applied to specific Jupiter orbiter missions. Possible image sequence plans for Jupiter missions are discussed in detail. Considered is a series of orbits that allow repeated near encounters with three of the Jovian satellites. The data handling involved in the image processing is discussed, and it is shown that only minimal processing is required for the majority of images for a Jupiter orbiter mission.

  8. Scorched Planets: Understanding the Structure and Climate of Hot Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Colón, Knicole; Martioli, Eder; Angerhausen, Daniel; Rodriguez, Joseph E.; Zhou, George; Pepper, Joshua; Stassun, Keivan; Gaudi, B. Scott; James, David; Eastman, Jason; Beatty, Thomas G.; Bayliss, Daniel

    2015-12-01

    Radial velocity and transit surveys have revealed that hot Jupiters are intrinsically rare in the Galaxy. These extreme examples of extrasolar planets have been the subject of many studies to date, but their formation and evolution are still shrouded in mystery. I will present results from a large ground-based survey to study the atmospheres of hot Jupiters via their secondary eclipses in the near-infrared. Such observations provide us with a direct measurement of thermal emission from a planet’s day-side, allowing us to probe the connection between the atmospheric structure and climate deep in their atmospheres, as well as the irradiation from their host star. I will present results obtained for several hot Jupiters using the wide-field camera WIRCam on the 3.6m Canada-France-Hawaii-Telescope (CFHT). The sample of hot Jupiters observed to date in the CFHT survey spans a range of planetary parameters (e.g. temperatures and densities) and also includes several new exotic discoveries from the KELT transit survey, such as a planet in a hierarchical triple stellar system as well as a planet with a very rapidly rotating host star. Results from the CFHT survey will be combined with those from an ongoing survey of hot Jupiter eclipses in the southern hemisphere using the 3.9m Anglo-Australian Telescope as well as an upcoming survey using the 4m Mayall Telescope at Kitt Peak National Observatory. The combined survey will be the largest homogeneous study of this kind to date, and it will provide us with the congruent observations of a significant number of unique planets in eclipse. These observations will ultimately allow a comprehensive statistical analysis of the diversity of hot Jupiter atmospheres via their near-infrared eclipses. In addition, this project will identify legacy targets for comparative exoplanetology using next-generation facilities such as the James Webb Space Telescope.

  9. Mass Spectrometry in Jupiter's Atmosphere: Vertical Variation of Volatile Vapors

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; Atreya, Sushil K.; Mahaffy, Paul R.

    2014-05-01

    The Galileo Probe made the first and only in situ measurements of composition in Jupiter's atmosphere, led by the Galileo Probe Mass Spectrometer, or GPMS [1]. The major contribution from this instrument was the measurement of abundances and isotope ratios of the noble gases, as well as the volatile gases CH4, NH3, H2O, and H2S [2,3]. These initial results were further refined by detailed laboratory calibrations for the noble gases [4] and the volatiles [5]. The probe measurements resulted in the first determination of the heavy element abundances (except carbon that was known previously) and He/H ratio, which provide critical constraints to models of the formation of Jupiter and the origin of its atmosphere [6,7]. The condensable volatiles, or CVs (ammonia, H2S, and water), increased with depth in the probe entry site. This vertical variation was observed at levels much deeper than the modeled cloud bases, as predicted by one-dimensional chemical equilibrium models. The discrepancy is due to the probe's entry into a dry region known as a 5-?m hot spot. The 5-?m hot spots are part of an atmospheric wave system that encircles Jupiter just north of the equator. Despite the anomalous meteorology, the bulk abundances of NH3 and H2S were measured by the probe, and found to be enriched with respect to solar composition (similarly to the non-condensable volatile CH4). The deepest water mixing ratio, however, was observed to be depleted relative to solar composition. We review an updated context for the CV vertical profiles measured by the GPMS, based on the latest results from remote sensing, simulation, and reinterpretation of Galileo Probe measurements. In particular, we find that (1) the bulk abundance of water in Jupiter's atmosphere must be greater than the subsolar abundance derived from the deepest GPMS measurements [8], and that (2) CV mixing ratios are controlled by a range of processes in addition to condensation of the ices NH3, NH4SH, and H2O [5-9]. Both bulk abundances and spatial variation of these species will be further constrained by the Juno mission, scheduled to arrive at Jupiter in 2016. References: [1] Niemann, H.B. et al. 1992, SSRv 60, 111-142 [2] Niemann, H.B. et al. 1996, Science 272, 846-849 [3] Niemann, H.B. et al. 1998, JGR 103, 22831-22845 [4] Mahaffy, P.R. et al. 2000, JGR 105, 15061-15071 [5] Wong, M.H. et al. 2004, Icarus 171, 153-170 [6] Atreya, S.K. et al., 1999, Planet. Space Sci. 47, 1243-1262 [7] Atreya, S.K. et al., 2003, Planet. Space Sci. 451, 105-112 [8] Wong, M.H. et al., 2008, in Reviews in Mineralogy and Geochemistry, vol. 68. Mineralogical Society of America, Chantilly, VA, pp. 219-246 [9] Wong, M.H., 2009, Icarus 199, 231-235

  10. Inferring Planet Mass from Spiral Structures in Protoplanetary Disks

    E-print Network

    Fung, Jeffrey

    2015-01-01

    Recent observations of protoplanetary disk have reported spiral structures that are potential signatures of embedded planets, and modeling efforts have shown that a single planet can excite multiple spiral arms, in contrast to conventional disk-planet interaction theory. Using two and three-dimensional hydrodynamics simulations to perform a systematic parameter survey, we confirm the existence of multiple spiral arms in disks with a single planet, and discover a scaling relation between the azimuthal separation of the primary and secondary arm, $\\phi_{\\rm sep}$, and the planet-to-star mass ratio $q$: $\\phi_{\\rm sep} = 102^{\\circ} (q/0.001)^{0.2}$ for companions between Neptune mass and 16 Jupiter masses around a 1 solar mass star, and $\\phi_{\\rm sep} = 180^{\\circ}$ for brown dwarf mass companions. This relation is independent of the disk's temperature, and can be used to infer a planet's mass to within an accuracy of about 30% given only the morphology of a face-on disk. Combining hydrodynamics and Monte-Carl...

  11. TrES-5: A MASSIVE JUPITER-SIZED PLANET TRANSITING A COOL G DWARF

    SciTech Connect

    Mandushev, Georgi; Dunham, Edward W.; Quinn, Samuel N.; Latham, David W.; Charbonneau, David; Buchhave, Lars A.; Rabus, Markus; Oetiker, Brian; Brown, Timothy M.; Belmonte, Juan A.

    2011-11-10

    We report the discovery of TrES-5, a massive hot Jupiter that transits the star GSC 03949-00967 every 1.48 days. From spectroscopy of the star we estimate a stellar effective temperature of T{sub eff} = 5171 {+-} 36 K, and from high-precision B, R, and I photometry of the transit we constrain the ratio of the semimajor axis a and the stellar radius R{sub *} to be a/R{sub *} = 6.07 {+-} 0.14. We compare these values to model stellar isochrones to obtain a stellar mass of M{sub *} = 0.893 {+-} 0.024 M{sub Sun }. Based on this estimate and the photometric time series, we constrain the stellar radius to be R{sub *} = 0.866 {+-} 0.013 R{sub Sun} and the planet radius to be R{sub p} = 1.209 {+-} 0.021 R{sub J}. We model our radial-velocity data assuming a circular orbit and find a planetary mass of 1.778 {+-} 0.063 M{sub J}. Our radial-velocity observations rule out line-bisector variations that would indicate a specious detection resulting from a blend of an eclipsing binary system. TrES-5 orbits one of the faintest stars with transiting planets found to date from the ground and demonstrates that precise photometry and followup spectroscopy are possible, albeit challenging, even for such faint stars.

  12. From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets

    NASA Astrophysics Data System (ADS)

    Perez-Becker, Daniel Alonso

    2013-12-01

    This dissertation is composed of three independent projects in astrophysics concerning phenomena that are concurrent with the birth, life, and death of planets. In Chapters 1 & 2, we study surface layer accretion in protoplanetary disks driven stellar X-ray and far-ultraviolet (FUV) radiation. In Chapter 3, we identify the dynamical mechanisms that control atmospheric heat redistribution on hot Jupiters. Finally, in Chapter 4, we characterize the death of low-mass, short-period rocky planets by their evaporation into a dusty wind. Chapters 1 & 2: Whether protoplanetary disks accrete at observationally significant rates by the magnetorotational instability (MRI) depends on how well ionized they are. We find that disk surface layers ionized by stellar X-rays are susceptible to charge neutralization by condensates---ranging from mum-sized dust to angstrom-sized polycyclic aromatic hydrocarbons (PAHs). Ion densities in X-ray-irradiated surfaces are so low that ambipolar diffusion weakens the MRI. In contrast, ionization by stellar FUV radiation enables full-blown MRI turbulence in disk surface layers. Far-UV ionization of atomic carbon and sulfur produces a plasma so dense that it is immune to ion recombination on grains and PAHs. Even though the FUV-ionized layer is ˜10--100 times more turbulent than the X-ray-ionized layer, mass accretion rates of both layers are comparable because FUV photons penetrate to lower surface densities than do X-rays. We conclude that surface layer accretion occurs at observationally significant rates at radii ? 1--10 AU. At smaller radii, both X-ray- and FUV-ionized surface layers cannot sustain the accretion rates generated at larger distance and an additional means of transport is needed. In the case of transitional disks, it could be provided by planets. Chapter 3: Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides than colder planets. Here we present a shallow water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, tauwave, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when tauwave ˜ (taurad /o)1/2, where taurad is the radiative relaxation time of the atmosphere and o is the planetary rotation frequency. Our results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between taurad and the horizontal day-night advection timescale, tauadv. Chapter 4: Short-period exoplanets can have dayside surface temperatures surpassing 2000 K, hot enough to vaporize rock and drive a thermal wind. Small enough planets evaporate completely. Here we construct a radiative-hydrodynamic model of atmospheric escape from strongly irradiated, low-mass rocky planets, accounting for dust-gas energy exchange in the wind. Rocky planets with masses ? 0.1 MEarth (less than twice the mass of Mercury) and surface temperatures ? 2000 K are found to disintegrate entirely in ? 10 Gyr. When our model is applied to Kepler planet candidate KIC 12557548b---which is believed to be a rocky body evaporating at a rate of dM/dt ? 0.1 MEarth/Gyr---our model yields a present-day planet mass of ? 0.02 MEarth or less than about twice the mass of the Moon. Mass loss rates depend so strongly on planet mass that bodies can reside on close-in orbits for Gyrs with initial masses comparable to or less than that of Mercury, before entering a final short-lived phase of c

  13. The architecture of the multi-planet system of ? And: ? And b - a super-inflated hot Jupiter in a cosmic ping-pong game

    NASA Astrophysics Data System (ADS)

    Rodler, Florian

    2015-12-01

    The gas giant Upsilon Andromeda b (? And b) was one of the first discovered exoplanets. This planet orbits around a bright, similar to the Sun star only 13.5 parsecs away from us. ? And b is also the innermost planet of a confirmed three-planet system, all of them non-transiting. As with all non-transiting planets, their exact masses and sizes are unknown, with their orbital inclination being the key parameter to unveil those values. Astrometric measurements have placed constraints to the orbital inclinations of the two outer planets in this system, indicating that we look almost 'face-on' on the system (McArthur et al. 2010). However, the orbital inclination for the innermost planet remained unknown.Photometric monitoring of ? And b orbit at infrared wavelengths has revealed significant brightness changes between the day-side and the night-side of the planet (Crossfield et al. 2010). The amplitude of those brightness variations depends on the orbital inclination of the planet and on its radius, therefore we can tightly constrain the size of the planet if its inclination is known.Here we present the measurement of the orbital inclination for the innermost planet ? And b, 23 deg, obtained by monitoring the Doppler shift of carbon monoxide (CO) lines on the atmospheric day-side of the planet with Keck/NIRSPEC. From this measurement we establish a planet mass of 1.7 times the mass of Jupiter and a minimum planet radius of 1.8 times the size of Jupiter. This result reveals that ? And b is likely to be one of the most inflated giant planets discovered to date. In addition, the observed strong CO absorption suggests an atmosphere with temperature uniformly decreasing towards higher altitudes, which suggests the absence of an atmospheric thermal inversion (Rodler et al. 2015).

  14. Transit thermal control design for Galileo entry probe for planet Jupiter

    NASA Technical Reports Server (NTRS)

    Haverly, G. C.; Pitts, W.

    1982-01-01

    A totally passive design was completed for the thermal control of the Galileo entry probe during its transit to the planet Jupiter. The design utilizes radio isotope heater units, multilayer insulation blankets and a thermal radiator in conjunction with a design conductance support structure to achieve both the required storage and critical initial planet atmosphere entry temperatures. The probe transit thermal design was completed and verified based on thermal vacuum testing of a prototype probe thermal test model.

  15. The sub-Jupiter mass transiting exoplanet WASP-11b

    E-print Network

    R. G. West; A. Collier Cameron; L. Hebb; Y. C. Joshi; D. Pollacco; E. Simpson; I. Skillen; H. C. Stempels; P. J. Wheatley; D. Wilson; D. Anderson; S. Bentley; F. Bouchy; B. Enoch; N. Gibson; G. Hébrard; C. Hellier; B. Loeillet; M. Mayor; P. Maxted; I. McDonald; C. Moutou; F. Pont; D. Queloz; A. M. S. Smith; B. Smalley; R. A. Street; S. Udry

    2008-09-26

    We report the discovery of a sub-Jupiter mass exoplanet transiting a magnitude V=11.7 host star 1SWASP J030928.54+304024.7. A simultaneous fit to the transit photometry and radial-velocity measurements yield a planet mass M_p=0.53+-0.07M_J, radius R_p=0.91^{+0.06}_{-0.03}R_J and an orbital period of 3.722465^{+0.000006}_{-0.000008} days. The host star is of spectral type K3V, with a spectral analysis yielding an effective temperature of 4800+-100K and log g=4.45+-0.2. It is amongst the smallest, least massive and lowest luminosity stars known to harbour a transiting exoplanet. WASP-11b is the third least strongly irradiated transiting exoplanet discovered to date, experiencing an incident flux F_p=1.9x10^8 erg s^{-1} cm^{-2} and having an equilibrium temperature T_eq=960+-70K.

  16. Planets of the solar system. [Jupiter and Venus

    NASA Technical Reports Server (NTRS)

    Kondratyev, K. Y.; Moskalenko, N. I.

    1978-01-01

    Venera and Mariner spacecraft and ground based radio astronomy and spectroscopic observations of the atmosphere and surface of venus are examined. The composition and structural parameters of the atmosphere are discussed as the basis for development of models and theories of the vertical structure of the atmosphere, the greenhouse effect, atmospheric circulation and cloud cover. Recommendations for further meteorological studies are given. Ground based and Pioneer satellite observation data on Jupiter are explored as well as calculations and models of the cloud structure, atmospheric circulation and thermal emission field of Jupiter.

  17. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. I. MEASURING PHOTOMETRIC ECCENTRICITIES OF INDIVIDUAL TRANSITING PLANETS

    SciTech Connect

    Dawson, Rebekah I.; Johnson, John Asher

    2012-09-10

    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the 'cold' Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations-part of the 'photoeccentric' light curve signature of a planet's eccentricity-even with long-cadence Kepler photometry and loosely constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71{sup +0.16}{sub -0.09}, in good agreement with the discovery value e = 0.67 {+-} 0.08 based on 33 radial-velocity measurements. We present two additional tests using Kepler data. In each case, the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto-hot Jupiters predicted by Socrates et al.

  18. A Mass Function Constraint on Extrasolar Giant Planet Evaporation Rates

    E-print Network

    W. B Hubbard; M. Hattori; A. Burrows; I. Hubeny

    2007-02-09

    The observed mass function for all known extrasolar giant planets (EGPs) varies approximately as M^{-1} for mass M between 0.2 Jupiter masses (M_J) and 5 M_J. In order to study evaporation effects for highly-irradiated EGPs in this mass range, we have constructed an observational mass function for a subset of EGPs in the same mass range but with orbital radii evaporation, this result places a constraint on orbital migration models and rules out the most extreme mass loss rates in the literature. A theory that predicts more moderate mass loss gives a mass function that is closer to observed statistics but still disagrees for M < 1 M_J.

  19. WASP-77 Ab: A Transiting Hot Jupiter Planet in a Wide Binary System

    NASA Astrophysics Data System (ADS)

    Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A.; Doyle, A. P.; Fumel, A.; Gillon, M.; Hellier, C.; Jehin, E.; Lendl, M.; Pepe, F.; Pollacco, D. L.; Queloz, D.; Ségransan, D.; Smalley, B.; Southworth, K.; Smith, A. M. S.; Triaud, A. H. M. J.; Udry, S.; West, R. G.

    2013-01-01

    We report the discovery of a transiting planet with an orbital period of 1.36 days orbiting the brighter component of the visual binary star BD 07 436. The host star, WASP-77 A, is a moderately bright G8 V star (V=10.3) with a metallicity close to solar ([Fe/H] = 0.0 ± 0.1). The companion star, WASP-77 B, is a K-dwarf approximately 2 mag fainter at a separation of approximately 3?. The spectrum of WASP-77 A shows emission in the cores of the Caii H and K lines, indicative of moderate chromospheric activity. The Wide Angle Search for Planets (WASP) light curves show photometric variability with a period of 15.3 days and an amplitude of about 0.3% that is probably due to the magnetic activity of the host star. We use an analysis of the combined photometric and spectroscopic data to derive the mass and radius of the planet (1.76 ± 0.06 MJup, 1.21 ± 0.02 RJup). The age of WASP-77 A estimated from its rotation rate (˜1 Gyr) agrees with the age estimated in a similar way for WASP-77 B (˜0.6 Gyr) but is in poor agreement with the age inferred by comparing its effective temperature and density to stellar models (˜8 Gyr). Follow-up observations of WASP-77 Ab will make a useful contribution to our understanding of the influence of binarity and host star activity on the properties of hot Jupiters.

  20. A Venus-mass Planet Orbiting a Brown Dwarf: A Missing Link between Planets and Moons

    NASA Astrophysics Data System (ADS)

    Udalski, A.; Jung, Y. K.; Han, C.; Gould, A.; Koz?owski, S.; Skowron, J.; Poleski, R.; Soszy?ski, I.; Pietrukowicz, P.; Mróz, P.; Szyma?ski, M. K.; Wyrzykowski, ?.; Ulaczyk, K.; Pietrzy?ski, G.; Shvartzvald, Y.; Maoz, D.; Kaspi, S.; Gaudi, B. S.; Hwang, K.-H.; Choi, J.-Y.; Shin, I.-G.; Park, H.; Bozza, V.

    2015-10-01

    The co-planarity of solar system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hundreds of co-planar planetary systems by the Kepler satellite demonstrate that this formation mechanism is extremely widespread. Many moons in the solar system, such as the Galilean moons of Jupiter, also formed out of the accretion disks that coalesced into the giant planets. Here we report the discovery of an intermediate system, OGLE-2013-BLG-0723LB/Bb, composed of a Venus-mass planet orbiting a brown dwarf, which may be viewed either as a scaled-down version of a planet plus a star or as a scaled-up version of a moon plus a planet orbiting a star. The latter analogy can be further extended since they orbit in the potential of a larger, stellar body. For ice-rock companions formed in the outer parts of accretion disks, like Uranus and Callisto, the scaled masses and separations of the three types of systems are similar, leading us to suggest that the formation processes of companions within accretion disks around stars, brown dwarfs, and planets are similar.

  1. An Absence of Hot Jupiter Planets in 47 Tucanae: Results of a Wide-Field Transit Search

    E-print Network

    David T. F Weldrake; Penny D Sackett; Kenneth C Freeman; Terry J Bridges

    2004-11-09

    We present the results of a comprehensive wide field search for transiting ``Hot Jupiter'' planets (1dplanet frequency in 47 Tuc by observing, from the ground, a 52'x52' field centered on the cluster for 30.4 nights. Hence this work is most sensitive to the uncrowded outer regions of the cluster and concentrates on 21,920 main sequence stars (~solar in mass). This work comprises the largest ground-based transit search of a globular cluster to date. Monte Carlo simulations predict that seven planets should be present in our dataset, if 47 Tuc has the same planetary frequency observed in the solar neighbourhood. A detailed search with a custom developed detection algorithm found no transit events. Being consistent with the cluster core null detection of Gilliland and coworkers, our result indicates that system metallicity is the dominant effect inhibiting Hot Jupiter formation in this environment.

  2. Search for X rays from the planet Jupiter.

    NASA Technical Reports Server (NTRS)

    Hurley, K. C.

    1972-01-01

    Actively collimated balloon-borne scintillation counters employing a special phoswich anticoincidence technique were flown a total of 5 times from Palestine, Texas. Jupiter was observed for a total of 133 min, and an upper limit to the flux of X rays present at the observation time is .016 X rays/sq cm sec in the energy range 30-100 keV. Three separate calculations are made to estimate the flux of Jovian X rays at the earth. These estimates range from .000000001 to .1 X rays/sq cm sec in the energy range 30-100 keV. It is concluded that, since there was no decametric emission at the time of the flight and there had been no significant solar activity for several days prior to the flight, no X rays were being generated at the time of the observation.

  3. A Venus-Mass Planet Orbiting a Brown Dwarf: Missing Link between Planets and Moons

    E-print Network

    Udalski, A; Han, C; Gould, A; Kozlowski, S; Skowron, J; Poleski, R; Soszy?ski, I; Pietrukowicz, P; Mróz, P; Szyma?ski, M K; Wyrzykowski, ?; Ulaczyk, K; Pietrzy?ski, G; Shvartzvald, Y; Maoz, D; Kaspi, S; Gaudi, B S; Hwang, K -H; Choi, J -Y; Shin, I -G; Park, H; Bozza, V

    2015-01-01

    The co-planarity of solar-system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hundreds of co-planar planetary systems by the {\\it Kepler} satellite demonstrate that this formation mechanism is extremely widespread. Many moons in the solar system, such as the Galilean moons of Jupiter, also formed out of the accretion disks that coalesced into the giant planets. We report here the discovery of an intermediate system OGLE-2013-BLG-0723LB/Bb composed of a Venus-mass planet orbiting a brown dwarf, which may be viewed either as a scaled down version of a planet plus star or as a scaled up version of a moon plus planet orbiting a star. The latter analogy can be further extended since they orbit in the potential of a larger, stellar body. For ice-rock companions formed in the outer parts of accretion disks, like Uranus and Callisto, the scaled masses and separations of the three types of systems are similar, leading us ...

  4. EMBRYO IMPACTS AND GAS GIANT MERGERS. I. DICHOTOMY OF JUPITER AND SATURN's CORE MASS

    SciTech Connect

    Li Shulin; Agnor, C.B.; Lin, D. N. C.

    2010-09-10

    Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there are high-density cores with masses larger than 10 Earth masses. According to the conventional sequential accretion hypothesis, such massive cores are needed for the onset of efficient accretion of their gaseous envelopes. However, Jupiter's gaseous envelope is more massive and its core may be less massive than those of Saturn. In order to account for this structural diversity and the super-solar metallicity in the envelope of Jupiter and Saturn, we investigate the possibility that they may have either merged with other gas giants or consumed several Earth-mass protoplanetary embryos during or after the rapid accretion of their envelope. In general, impinging sub-Earth-mass planetesimals disintegrate in gas giants' envelopes, deposit heavy elements well outside the cores, and locally suppress the convection. Consequently, their fragments sediment to promote the growth of cores. Through a series of numerical simulations, we show that it is possible for colliding super-Earth-mass embryos to reach the cores of gas giants. Direct parabolic collisions also lead to the coalescence of gas giants and merging of their cores. In these cases, the energy released from the impact leads to vigorous convective motion throughout the envelope and the erosion of the cores. This dichotomy contributes to the observed dispersion in the internal structure and atmospheric composition between Jupiter and Saturn and other gas giant planets and elsewhere.

  5. PHOTO ILLUSTRATION OF COMET P/SHOEMAKER-LEVY 9 and PLANET JUPITER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a composite photo, assembled from separate images of Jupiter and comet P/Shoemaker-Levy 9, as imaged by the Wide Field and Planetary Camera-2 (WFPC-2), aboard NASA's Hubble Space Telescope (HST). Jupiter was imaged on May 18, 1994, when the giant planet was at a distance of 420 million miles (670 million km) from Earth. This 'true-color' picture was assembled from separate HST exposures in red, blue, and green light. Jupiter's rotation between exposures creates the blue and red fringe on either side of the disk. HST can resolve details in Jupiter's magnificent cloud belts and zones as small as 200 miles (320 km) across (wide field mode). This detailed view is only surpassed by images from spacecraft that have traveled to Jupiter. The dark spot on the disk of Jupiter is the shadow of the inner moon Io. This volcanic moon appears as an orange and yellow disk just to the upper right of the shadow. Though Io is approximately the size of Earth's Moon (but 2,000 times farther away), HST can resolve surface details. When the comet was observed on May 17, its train of 21 icy fragments stretched across 710 thousand miles (1.1 million km) of space, or 3 times the distance between Earth and the Moon. This required six WFPC exposures along the comet train to include all the nuclei. The image was taken in red light. The apparent angular size of Jupiter relative to the comet, and its angular separation from the comet when the images were taken, have been modified for illustration purposes. Credit: H.A. Weaver, T.E. Smith (Space Telescope Science Institute) and J.T. Trauger, R.W. Evans (Jet Propulsion Laboratory), and NASA

  6. A Definition for Giant Planets Based on the Mass-Density Relationship

    NASA Astrophysics Data System (ADS)

    Hatzes, Artie P.; Rauer, Heike

    2015-09-01

    We present the mass-density relationship (log M - log ?) for objects with masses ranging from planets (M ? 0.01 MJup) to stars (M > 0.08 M?). This relationship shows three distinct regions separated by a change in slope in the log M - log ? plane. In particular, objects with masses in the range 0.3 MJup-60 MJup follow a tight linear relationship with no distinguishing feature to separate the low-mass end (giant planets) from the high-mass end (brown dwarfs). We propose a new definition of giant planets simply based on changes in the slope of the log M versus log ? relationship. By this criterion, objects with masses less than ?0.3 MJup are low-mass planets, either icy or rocky. Giant planets cover the mass range 0.3 MJup-60 MJup. Analogous to the stellar main sequence, objects on the upper end of the giant planet sequence (brown dwarfs) can simply be referred to as “high-mass giant planets,” while planets with masses near that of Jupiter can be called “low-mass giant planets.”

  7. PLANET HUNTERS. V. A CONFIRMED JUPITER-SIZE PLANET IN THE HABITABLE ZONE AND 42 PLANET CANDIDATES FROM THE KEPLER ARCHIVE DATA

    SciTech Connect

    Wang, Ji; Fischer, Debra A.; Boyajian, Tabetha S.; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M.; Barclay, Thomas; Schwamb, Megan E.; Lintott, Chris; Simpson, Robert; Jek, Kian J.; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Smith, Arfon M.; Parrish, Michael; Lynn, Stuart; Schawinski, Kevin; and others

    2013-10-10

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R{sub PL} = 10.12 ± 0.56 R{sub ?}) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false-positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least 3 transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between those of Neptune and Jupiter. These detections nearly double the number of gas-giant planet candidates orbiting at habitable-zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events.

  8. COUPLED EVOLUTIONS OF THE STELLAR OBLIQUITY, ORBITAL DISTANCE, AND PLANET'S RADIUS DUE TO THE OHMIC DISSIPATION INDUCED IN A DIAMAGNETIC HOT JUPITER AROUND A MAGNETIC T TAURI STAR

    SciTech Connect

    Chang, Yu-Ling; Gu, Pin-Gao; Bodenheimer, Peter H.

    2012-10-01

    We revisit the calculation of the ohmic dissipation in a hot Jupiter presented by Laine et al. by considering more realistic interior structures, stellar obliquity, and the resulting orbital evolution. In this simplified approach, the young hot Jupiter of one Jupiter mass is modeled as a diamagnetic sphere with a finite resistivity, orbiting across tilted stellar magnetic dipole fields in vacuum. Since the induced ohmic dissipation occurs mostly near the planet's surface, we find that the dissipation is unable to significantly expand the young hot Jupiter. Nevertheless, the planet inside a small corotation orbital radius can undergo orbital decay by the dissipation torque and finally overfill its Roche lobe during the T Tauri star phase. The stellar obliquity can evolve significantly if the magnetic dipole is parallel/antiparallel to the stellar spin. Our results are validated by the general torque-dissipation relation in the presence of the stellar obliquity. We also run the fiducial model of Laine et al. and find that the planet's radius is sustained at a nearly constant value by the ohmic heating, rather than being thermally expanded to the Roche radius as suggested by the authors.

  9. Extrasolar Planets and the Rotation and Axisymmetrical mass loss of evolved stars

    E-print Network

    Noam Soker

    2000-06-26

    I examine the implications of the recently found extrasolar planets on the planet-induced axisymmetrical mass loss model for the formation of elliptical planetary nebulae (PNs). This model, which was developed in several earlier papers by the author and a few collaborators, attributes low departure from spherical mass loss of upper asymptotic giant branch (AGB) stars to envelope rotation which results from deposition of planet's orbital angular momentum. It was predicted that about 50 percent of all sun-like stars have Jupiter-like planets around them. In light of the new finding that only 5 percent of sun-like stars do have such planets I revise this prediction. I now predict that indeed about 50 percent of PNs progenitors do have close planets around them, but the planets can have much lower masses, as low as 0.01 times Jupiter's mass. To support this claim I follow the angular momentum evolution of single stars as they evolve to the post-AGB phase. The prediction that on average several such planets orbit each star, as in the solar system, still holds.

  10. Solar nebula constraints derived from the masses and formation times of Earth, Mars, Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Mosqueira, Ignacio; Lichtig, Ryan

    2014-11-01

    Terrestrial planets accreted from the late-stage collisional evolution of planetary embryos (roughly Mars-sized) and leftover planetesimals (Chambers 2013). Since the timescale to produce Earth-like analogues is on the order of ~ 100 My, the solar nebula gas would have dissipated by then. On the other hand, Hf-W chronology yields a short accretion timescale for Mars ~9 My (Dauphas and Pourmand 2011), which is similar to the gas dissipation time (Haisch et al. 2011). The Grand-Tack model proposes that Jupiter and Saturn migrated inward until Saturn was caught in a 2:3 mean motion resonance then migrated outward, truncating the disk in the process and accounting for Mars’ orbit, accretion timescale, and small mass (Walsh et al. 2011). However, in order to power the migration of the giant planets this model assumes the presence of a massive (compared to Jupiter) viscously evolving gas disk. This means that the giant planets themselves would not have completed their growth. Thus, the Grand-Tack model provides an explanation for the small mass of Mars at the cost of ignoring the resulting problematic large mass of Saturn. Here we fix the locations and masses of Jupiter and Saturn and develop a model in which the depleted region is due to three key mechanisms: one, removal of collisional fragments by gas drag; two, coalescence of planetary embryos by sweeping secular resonances during gas disk dispersal; three, removal of planetary embryos by Type I tidal interaction with the gas disk. We use analytical and numerical N-body results to evaluate the consequences of the above processes for the disk of solids. We focus on the variables controlling the extent of the depleted region. We stress that the static giant planets nevertheless play a determining role: first, by filtering-out outer disk planetesimal fragments that would otherwise replenish the inner disk; second, by increasing the (phased) eccentricities of planetary embryos thereby allowing larger objects to form; third, by opening gaps in the gas disk and thus setting the boundary conditions for the Type I tidal interaction of the planetary embryos with the nebula gas. In particular, the embryo’s Type I migration depends on the location of Jupiter.

  11. Using Jupiter's Volatile Inventory to Trace the History Of Ices During Planet Formation

    NASA Astrophysics Data System (ADS)

    Ciesla, F.

    2014-12-01

    The Galileo probe's measurement of a uniform enrichment of Jupiter's atmosphere in volatiles, including noble gases, relative to a gas of solar composition has proven to be a challenge to models of planet formation. This uniform enrichment requires that Jupiter accreted planetesimals with solar ratios in all elements, except for hydrogen and helium. Given the very low temperatures needed to achieve such compositions if all elements behaved chemically as pure substances, efforts have focused on understanding how extremely volatile elements could be physically incorporated into ices and organics at low temperatures. Two primary methods for incorporation of these volatiles have emerged: formation of clathrate hydrates and trapping of gases during the formation of amorphous ice. These modes for incorporating volatiles make different predictions about the amount of water that would be contained within Jupiter, an issue that will be addressed by the Juno Mission. Either mode for incorporating volatiles will reveal details about the dynamical behavior of ices during planet formation and the environments in which planetary materials were formed. For example, Ciesla (2014) showed that amorphous ice formation, and thus trapping of volatiles in this manner, can occur as water molecules are photodesorbed and freeze-out again on grain surfaces, thus requiring high UV flux environments at the birth of the solar system or significant vertical lofting of grains in the disk by turbulence. I will review the conditions that are required for amorphous trapping and clathrate hydrate formation to have occurred in the solar nebula and discuss the implications for the compositions of the other giant planets and cometary bodies, as well as the relation of these materials to the sources of volatiles on terrestrial planets.

  12. The mass disruption of Jupiter Family comets

    NASA Astrophysics Data System (ADS)

    Belton, Michael J. S.

    2015-01-01

    I show that the size-distribution of small scattered-disk trans-neptunian objects when derived from the observed size-distribution of Jupiter Family comets (JFCs) and other observational constraints implies that a large percentage (94-97%) of newly arrived active comets within a range of 0.2-15.4 km effective radius must physically disrupt, i.e., macroscopically disintegrate, within their median dynamical lifetime. Additional observational constraints include the numbers of dormant and active nuclei in the near-Earth object (NEO) population and the slope of their size distributions. I show that the cumulative power-law slope (-2.86 to -3.15) of the scattered-disk TNO hot population between 0.2 and 15.4 km effective radius is only weakly dependent on the size-dependence of the otherwise unknown disruption mechanism. Evidently, as JFC nuclei from the scattered disk evolve into the inner Solar System only a fraction achieve dormancy while the vast majority of small nuclei (e.g., primarily those with effective radius <2 km) break-up. The percentage disruption rate appears to be comparable with that of the dynamically distinct Oort cloud and Halley type comets (Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A., Bottke Jr., W.F. [2002]. Science 296, 2212-2215) suggesting that all types of comet nuclei may have similar structural characteristics even though they may have different source regions and thermal histories. The typical disruption rate for a 1 km radius active nucleus is ?5 × 10-5 disruptions/year and the dormancy rate is typically 3 times less. We also estimate that average fragmentation rates range from 0.01 to 0.04 events/year/comet, somewhat above the lower limit of 0.01 events/year/comet observed by Chen and Jewitt (Chen, J., Jewitt, D.C. [1994]. Icarus 108, 265-271).

  13. Delay of planet formation at large radius and the outward decrease in mass and gas content of Jovian planets

    NASA Astrophysics Data System (ADS)

    Jin, Li-Ping; Liu, Chun-Jian; Zhang, Yu

    2015-09-01

    A prominent observation of the solar system is that the mass and gas content of Jovian planets decrease outward with orbital radius, except that, in terms of these properties, Neptune is almost the same as Uranus. In previous studies, the solar nebula was assumed to preexist and the formation process of the solar nebula was not considered. It was therefore assumed that planet formation at different radii started at the same time in the solar nebula. We show that planet formation at different radii does not start at the same time and is delayed at large radii. We suggest that this delay might be one of the factors that causes the outward decrease in the masses of Jovian planets. The nebula starts to form from its inner part because of the inside-out collapse of its progenitorial molecular cloud core. The nebula then expands outward due to viscosity. Material first reaches a small radius and then reaches a larger radius, so planet formation is delayed at the large radius. The later the material reaches a planet's location, the less time it has to gain mass and gas content. Hence, the delay tends to cause the outward decrease in mass and gas content of Jovian planets. Our nebula model shows that the material reaches Jupiter, Saturn, Uranus and Neptune at t = 0.40, 0.57, 1.50 and 6.29 × 106 yr, respectively. We discuss the effects of time delay on the masses of Jovian planets in the framework of the core accretion model of planet formation. Saturn's formation is not delayed by much time relative to Jupiter so that they both reach the rapid gas accretion phase and become gas giants. However, the delay in formation of Uranus and Neptune is long and might be one of the factors that cause them not to reach the rapid gas accretion phase before the gas nebula is dispersed. Saturn has less time to go through the rapid gas accretion, so Saturn's mass and gas content are significantly less than those of Jupiter.

  14. THE MASS DISTRIBUTION OF SUBGIANT PLANET HOSTS

    SciTech Connect

    Lloyd, James P.

    2013-09-01

    High mass stars are hostile to Doppler measurements due to rotation and activity on the main-sequence, so RV searches for planets around massive stars have relied on evolved stars. A large number of planets have been found around evolved stars with M > 1.5 M{sub Sun }. To test the robustness of mass determinations, Lloyd compared mass distributions of planet hosting subgiants with distributions from integrating isochrones and concluded that it is unlikely the subgiant planet hosts are this massive, but rather that the mass inferences are systematically in error. The conclusions of Lloyd have been called in to question by Johnson et al., who show TRILEGAL-based mass distributions that disagree with the mass distributions in Lloyd, which they attribute to Malmquist bias. Johnson et al. argue that the very small spectroscopic observational uncertainties favor high masses, and there are a large number of high mass sub giants in RV surveys. However, in this Letter, it is shown that Malmquist bias does not impact the mass distributions, but the mass distribution is sensitive to Galaxy model. The relationship needed to reconcile the subgiant planet host masses with any model of the Galactic stellar population is implausible, and the conclusion of Lloyd that spectroscopic mass determinations of subgiants are likely to have been overestimated is robust.

  15. High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood

    E-print Network

    Salz, M; Czesla, S; Schmitt, J H M M

    2015-01-01

    Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should be detectable through Lyman alpha transit spectroscopy according to predictions. We use X-ray observations with Chandra and XMM-Newton of seven of these targets to derive the high-energy irradiation level of the planetary atmospheres and the resulting mass loss rates. We further derive improved Lyman alpha luminosity estimates for the host stars including interstellar absorption. According to our estimates WASP-80 b, WASP-77 b, and WASP-43 b experience the strongest mass loss rates, exceeding the mass loss rate of HD 209458 b, where an expanded atmosphere has been confirmed. Furthermore, seven out of nine targets might be amenable to Lyman alpha transit spectroscopy...

  16. Earth, Jupiter and Saturn as guides for extrasolar planets and brown dwarfs: a lightning climatology study

    NASA Astrophysics Data System (ADS)

    Hodosán, Gabriella; Asensio Torres, Rubén; Helling, Christiane; Vorgul, Irena

    2015-04-01

    Large-scale electrostatic discharges (i.e. lightning) have been observed in the Solar System. Apart from Earth there are direct detections from Jupiter and Saturn and indirect (only radio) detection from Uranus and Neptune. Recent observations made by the Venus Explorer revealed radio signals that may be related to lightning. Observations indicate that clouds form on extrasolar planets and brown dwarfs. The conditions in these clouds may be good for lightning to occur, which can be a main ionization process in these atmospheres (lightning in mineral clouds e.g.: Bailey et al. 2014, ApJ, 784, 43; Helling at al. 2013, ApJ, 767, 136; Helling et al. 2013, P&SS, 77, 152). In this study our aim is to compare lightning climatology from Earth, Jupiter and Saturn and use these statistics as a guide to study potential lightning on extrasolar planetary objects. Earth is a fair analogy for rocky or ocean planets while Jupiter and Saturn resemble giant planets and brown dwarfs. To give an estimate on the total lightning energy (or power) that can reach us from a particular extrasolar body, we need to know how much lightning can occur on the object globally. We will show the possibilities in the number and quality of the giant planet data sets, which may give a fine comparison of future observations of extrasolar giant gas planets and even brown dwarfs. Data were obtained from Lightning Imaging Sensor (LIS)/Optical Transient Detector (OTD) (e.g.: Cecil et al. 2014, Atmospheric Research, 135, 404), Sferics Timing and Ranging Network (STARNET) (e.g.: Morales Rodrigues et al. 2011, 2014, XIV and XV International Conference on Atmospheric Electricity) and World Wide Lightning Location Network (WWLLN) (e.g.: Hutchins et al. 2012, Radio Science, 47, RS6005), four major lightning detecting networks, which monitor lightning occurrence in the optical or radio range on Earth. We compare flash/stroke rates in space and time and use the data to refer to Earth as a transiting exoplanet. We analyze flash rates from a certain celestial direction (as if looked at Earth from outside the Solar System from a fixed location) to see how they vary as the planet orbits the star. The same comparison studies are conducted for Jupiter and Saturn from Galileo, Cassini and New Horizons data. The comparison of Earth-data shows the importance of the networks' detection efficiency (detected lightning over the total amount of lightning in percentages) and the location of the individual instruments of the networks. Characterizing exoplanets is a difficult task, however, there are planets in our Solar System, which are better studied. Here we show how using the knowledge we have on these planets is a key aspect of exoplanetary sciences. Acknowledgement: We thank Daniel J. Cecil from LIS/OTD, Carlos Augusto Morales Rodrigues from STARNET and Robert H. Holzworth from WWLLN who kindly helped us obtaining data from the lightning detecting networks. The authors wish to thank the World Wide Lightning Location Network (http://wwlln.net), a collaboration among over 50 universities and institutions, for providing the lightning location data used in this work.

  17. The lowest mass giant planet ever imaged around a star

    NASA Astrophysics Data System (ADS)

    Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Boccaletti, A.; Quanz, S. P.; Bonnefoy, M.; Girard, J. H.; Delorme, P.; Desidera, S.; Klahr, H.; Mordasini, C.; Dumas, C.; Bonavita, M.

    2013-09-01

    Understanding planetary systems formation and evolution has become one of the challenges in astronomy, since the discovery of the first exoplanet around the solar-type star 51 Peg in the 90's. While more than 800 planets (mostly giants) closer than a few AU have been identified with radial velocity and transit techniques, very few have been imaged and definitely confirmed around stars, at separations below a hundred of astronomical units. Direct imaging detection of exoplanet is indeed a major frontier in planetary astrophysics. It surveys a region of semi-major axes (> 5 AU) that is almost inaccessible to other methods. Moreover, the planets imaged so far orbit young stars; indeed the young planets are still hot and the planetstar contrasts are compatible with the detection limits currently achievable, in contrast with similar planets in older systems. Noticeably, the stars are of early-types, and surrounded by debris disks, i.e. disks populated at least by small grains with lifetimes so short that they must be permanently produced, probably by destruction (evaporation, collisions) of larger solid bodies. Consequently, every single discovery has a tremendous impact on the understanding of the formation, the dynamical evolution, and the physics of giant planets. In this context, I will present our recent discovery of one faint companion to a nearby, dusty, and young A-type star (at 56 AU projected separation). Background contaminants are rejected with high confidence level based on both astrometry and photometry with three dataset at more than a yeartime-laps and two different wavelength regimes. From the system age (10 to 17 Myr) and from model-dependent luminosity estimates, we derive mass of 4 to 5 Jupiter mass. This planet is therefore the one with the lowest mass ever imaged around a star. Given its orbital and physical properties, I will discuss the implication on its atmosphere with respect to other imaged companions but also on its formation which is not straightforward assuming standard mechanisms. This planet will be of great interest for future planets imagers to search for additional close-in and lower mass companions but also for spectral characterization.

  18. The potential for Earth-mass planet formation around brown dwarfs

    E-print Network

    Matthew J. Payne; Giuseppe Lodato

    2007-09-05

    Recent observations point to the presence of structured dust grains in the discs surrounding young brown dwarfs, thus implying that the first stages of planet formation take place also in the sub-stellar regime. Here, we investigate the potential for planet formation around brown dwarfs and very low mass stars according to the sequential core accretion model of planet formation. We find that, for a brown dwarfs of mass 0.05M_{\\odot}, our models predict a maximum planetary mass of ~5M_{\\oplus}, orbiting with semi-major axis ~1AU. However, we note that the predictions for the mass - semi-major axis distribution are strongly dependent upon the models chosen for the disc surface density profiles and the assumed distribution of disc masses. In particular, if brown dwarf disc masses are of the order of a few Jupiter masses, Earth-mass planets might be relatively frequent, while if typical disc masses are only a fraction of Jupiter mass, we predict that planet formation would be extremely rare in the sub-stellar regime. As the observational constraints on disc profiles, mass dependencies and their distributions are poor in the brown dwarf regime, we advise caution in validating theoretical models only on stars similar to the Sun and emphasise the need for observational data on planetary systems around a wide range of stellar masses. We also find that, unlike the situation around solar-like stars, Type-II migration is totally absent from the planet formation process around brown dwarfs, suggesting that any future observations of planets around brown dwarfs would provide a direct measure of the role of other types of migration.

  19. DETERMINATION OF THE MINIMUM MASSES OF HEAVY ELEMENTS IN THE ENVELOPES OF JUPITER AND SATURN

    SciTech Connect

    Mousis, Olivier; Lunine, Jonathan I.; Marboeuf, Ulysse; Alibert, Yann; Fletcher, Leigh N.; Orton, Glenn S.; Pauzat, Francoise; Ellinger, Yves

    2009-05-10

    We calculate the minimum mass of heavy elements required in the envelopes of Jupiter and Saturn to match the observed oversolar abundances of volatiles. Because the clathration efficiency remains unknown in the solar nebula, we have considered a set of sequences of ice formation in which the fraction of water available for clathration is varied between 0 and 100%. In all the cases considered, we assume that the water abundance remains homogeneous whatever the heliocentric distance in the nebula and directly derives from a gas phase of solar composition. Planetesimals then form in the feeding zones of Jupiter and Saturn from the agglomeration of clathrates and pure condensates in proportions fixed by the clathration efficiency. A fraction of Kr and Xe may have been sequestrated by the H{sup +} {sub 3} ion in the form of stable XeH{sup +} {sub 3} and KrH{sup +} {sub 3} complexes in the solar nebula gas phase, thus implying the formation of at least partly Xe- and Kr-impoverished planetesimals in the feeding zones of Jupiter and Saturn. These planetesimals were subsequently accreted and vaporized into the hydrogen envelopes of Jupiter and Saturn, thus engendering volatiles enrichments in their atmospheres, with respect to hydrogen. Taking into account both refractory and volatile components, and assuming plausible molecular mixing ratios in the gas phase of the outer solar nebula, we show that it is possible to match the observed enrichments in Jupiter and Saturn, whatever the clathration efficiency. Our calculations predict that the O/H enrichment decreases from {approx} 5.5 to 5.1 times (O/H){sub sun} in the envelope of Jupiter and from 15.2 to 14.1 times (O/H){sub sun} in the envelope of Saturn with the growing clathration efficiency in the solar nebula. As a result, the minimum mass of ices needed to be injected in the envelope of Jupiter decreases from {approx} 20.0 to 18.6 M {sub +}, including a mass of water diminishing from 10.4 to 9.3 M {sub +}. In the same conditions, the minimum mass of ices needed in the envelope of Saturn decreases from {approx} 16.7 to 15.6 M {sub +}, including a mass of water diminishing from 8.6 to 7.7 M {sub +}. The accretion of planetesimals with ices to rocks ratios {approx} 1 in the envelope of Jupiter, namely a value derived from the bulk densities of Ganymede and Callisto, remains compatible with the mass of heavy elements predicted by interior models. On the other hand, the accretion of planetesimals with similar ice-to-rock in the envelope of Saturn implies a mass of heavy elements greater than the one predicted by interior models, unless a substantial fraction of the accreted rock and water sedimented onto the core of the planet during its evolution.

  20. Friends of Hot Jupiters. III. An Infrared Spectroscopic Search for Low-mass Stellar Companions

    NASA Astrophysics Data System (ADS)

    Piskorz, Danielle; Knutson, Heather A.; Ngo, Henry; Muirhead, Philip S.; Batygin, Konstantin; Crepp, Justin R.; Hinkley, Sasha; Morton, Timothy D.

    2015-12-01

    Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary techniques to search for stellar companions to known planet-hosting stars: radial velocity monitoring, adaptive optics imaging, and near-infrared spectroscopy. In this paper, we examine high-resolution K band infrared spectra of fifty stars hosting gas giant planets on short-period orbits. We use spectral fitting to search for blended lines due to the presence of cool stellar companions in the spectra of our target stars, where we are sensitive to companions with temperatures between 3500 and 5000 K and projected separations less than 100 AU in most systems. We identify eight systems with candidate low-mass companions, including one companion that was independently detected in our AO imaging survey. For systems with radial velocity accelerations, a spectroscopic non-detection rules out scenarios involving a stellar companion in a high inclination orbit. We use these data to place an upper limit on the stellar binary fraction at small projected separations, and show that the observed population of candidate companions is consistent with that of field stars and also with the population of wide-separation companions detected in our previous AO survey. We find no evidence that spectroscopic stellar companions are preferentially located in systems with short-period gas giant planets on eccentric and/or misaligned orbits.

  1. Mass Transfer Stability of Hot Jupiters at Their Roche Limit

    NASA Astrophysics Data System (ADS)

    Fixelle, Joshua; Hwang, Jason; Valsecchi, Francesca; Rasio, Fred

    2015-12-01

    Many exoplanets have been detected in orbits close to their Roche limit. Through tidal dissipation, it is expected that their orbits will decay, initiating mass transfer via Roche lobe Overflow (RLO). Previous studies have looked at the RLO evolution of these planets, suggesting a Neptune or Earth mass remnant will remain after concluding mass transfer. However, a critical assumption entering such calculations is that the RLO mass transfer of these systems is stable. We present numerical calculations using smoothed-particle hydrodynamics to investigate the details of this mass transfer.

  2. HAT-P-34b-HAT-P-37b: FOUR TRANSITING PLANETS MORE MASSIVE THAN JUPITER ORBITING MODERATELY BRIGHT STARS

    SciTech Connect

    Bakos, G. A.; Hartman, J. D.; Csubry, Z.; Penev, K.; Torres, G.; Beky, B.; Latham, D. W.; Bieryla, A.; Quinn, S.; Szklenar, T.; Esquerdo, G. A.; Noyes, R. W.; Buchhave, L. A.; Kovacs, G.; Shporer, A.; Fischer, D. A.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Sato, B.; and others

    2012-07-15

    We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33 M{sub J} and periods from 1.33 to 5.45 days. These planets orbit relatively bright F and G dwarf stars (from V = 10.16 to V = 13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33 M{sub J}), has a high eccentricity of e = 0.441 {+-} 0.032 at a period of P = 5.452654 {+-} 0.000016 days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters.

  3. THE MASS OF KOI-94d AND A RELATION FOR PLANET RADIUS, MASS, AND INCIDENT FLUX

    SciTech Connect

    Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard; Kolbl, Rea; Rowe, Jason F.; Howell, Steve B.; Howard, Andrew W.; Fortney, Jonathan J.; Miller, Neil; Demory, Brice-Olivier; Seager, Sara; Fischer, Debra A.; Adams, Elisabeth R.; Dupree, Andrea K.; Johnson, John Asher; Horch, Elliott P.; Everett, Mark E.; Fabrycky, Daniel C.

    2013-05-01

    We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like inflated hot Jupiters. KOI-94 also hosts at least three smaller transiting planets, all of which were detected by the Kepler mission. With 26 radial velocities of KOI-94 from the W. M. Keck Observatory and a simultaneous fit to the Kepler light curve, we measure the mass of the giant planet and determine that it is not inflated. Support for the planetary interpretation of the other three candidates comes from gravitational interactions through transit timing variations, the statistical robustness of multi-planet systems against false positives, and several lines of evidence that no other star resides within the photometric aperture. We report the properties of KOI-94b (M{sub P} = 10.5 {+-} 4.6 M{sub Circled-Plus }, R{sub P} = 1.71 {+-} 0.16 R{sub Circled-Plus }, P = 3.74 days), KOI-94c (M{sub P} = 15.6{sup +5.7}{sub -15.6} M{sub Circled-Plus }, R{sub P} = 4.32 {+-} 0.41 R{sub Circled-Plus }, P = 10.4 days), KOI-94d (M{sub P} = 106 {+-} 11 M{sub Circled-Plus }, R{sub P} = 11.27 {+-} 1.06 R{sub Circled-Plus }, P = 22.3 days), and KOI-94e (M{sub P} = 35{sup +18}{sub -28} M{sub Circled-Plus }, R{sub P} = 6.56 {+-} 0.62 R{sub Circled-Plus }, P = 54.3 days). The radial velocity analyses of KOI-94b and KOI-94e offer marginal (>2{sigma}) mass detections, whereas the observations of KOI-94c offer only an upper limit to its mass. Using the KOI-94 system and other planets with published values for both mass and radius (138 exoplanets total, including 35 with M{sub P} < 150 M{sub Circled-Plus }), we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to 13 Jupiter masses: (R{sub P}/R{sub Circled-Plus }) = 1.78(M{sub P}/M{sub Circled-Plus }){sup 0.53}(F/erg s{sup -1} cm{sup -2}){sup -0.03} for M{sub P} < 150 M{sub Circled-Plus }, and R{sub P}/R{sub Circled-Plus} = 2.45(M{sub P}/M{sub Circled-Plus }){sup -0.039}(F/erg s{sup -1} cm{sup -2}){sup 0.094} for M{sub P} > 150 M{sub Circled-Plus }. These equations can be used to predict the radius or mass of a planet.

  4. The effects of the formation of a giant planet on the evolution of the protoplanetary disk: the case of Jupiter in the Solar System

    NASA Astrophysics Data System (ADS)

    Turrini, Diego

    2015-11-01

    The formation of a giant planet is one of the milestones in the life of a planetary system, as it plays a leading role in shaping its subsequent evolution. Once the core of the forming giant planet reaches the critical mass needed to trigger the hydrodynamical instability in the surrounding nebular gas and start the rapid phase of gas accretion, the planetary system in which the planet is embedded suddenly experience the appearance of a strong gravitational perturber. Even in absence of migration, this event will trigger a 0.5-1 Myr-long phase of violent remixing and enhanced collisional evolution of the planetary bodies in the protoplanetary disk. For what it concerns the giant planet itself, this primordial bombardment will result in the capture of high-Z material from a wide orbital range, including the inner regions of the planetary system. For what it concerns the other bodies of the protoplanetary disk, this phase of remixing and bombardment will result in the collisional erosion of the smallest planetesimals in the dynamically-excited orbital regions and in the delivery of water and volatile elements to the inner regions of the planetary system. While the mass growth of the giant planet is necessary and sufficient condition to trigger this primordial bombardment, planetary migration plays a major role in determining its intensity. Using the formation of Jupiter in the Solar System as our case study, we will illustrate how this event affects the Jovian system and the asteroid belt. Concerning the latter, we will also discuss how the composition of asteroid Vesta, whose formation and differentiation predate the formation of Jupiter, supplies information on the primordial dynamical evolution of the giant planet.

  5. ON THE MIGRATION OF JUPITER AND SATURN: CONSTRAINTS FROM LINEAR MODELS OF SECULAR RESONANT COUPLING WITH THE TERRESTRIAL PLANETS

    SciTech Connect

    Agnor, Craig B.; Lin, D. N. C.

    2012-02-01

    We examine how the late divergent migration of Jupiter and Saturn may have perturbed the terrestrial planets. Using a modified secular model we have identified six secular resonances between the {nu}{sub 5} frequency of Jupiter and Saturn and the four apsidal eigenfrequencies of the terrestrial planets (g{sub 1-4}). We derive analytic upper limits on the eccentricity and orbital migration timescale of Jupiter and Saturn when these resonances were encountered to avoid perturbing the eccentricities of the terrestrial planets to values larger than the observed ones. Because of the small amplitudes of the j = 2, 3 terrestrial eigenmodes the g{sub 2} - {nu}{sub 5} and g{sub 3} - {nu}{sub 5} resonances provide the strongest constraints on giant planet migration. If Jupiter and Saturn migrated with eccentricities comparable to their present-day values, smooth migration with exponential timescales characteristic of planetesimal-driven migration ({tau} {approx} 5-10 Myr) would have perturbed the eccentricities of the terrestrial planets to values greatly exceeding the observed ones. This excitation may be mitigated if the eccentricity of Jupiter was small during the migration epoch, migration was very rapid (e.g., {tau} {approx}< 0.5 Myr perhaps via planet-planet scattering or instability-driven migration) or the observed small eccentricity amplitudes of the j = 2, 3 terrestrial modes result from low probability cancellation of several large amplitude contributions. Results of orbital integrations show that very short migration timescales ({tau} < 0.5 Myr), characteristic of instability-driven migration, may also perturb the terrestrial planets' eccentricities by amounts comparable to their observed values. We discuss the implications of these constraints for the relative timing of terrestrial planet formation, giant planet migration, and the origin of the so-called Late Heavy Bombardment of the Moon 3.9 {+-} 0.1 Ga ago. We suggest that the simplest way to satisfy these dynamical constraints may be for the bulk of any giant planet migration to be complete in the first 30-100 Myr of solar system history.

  6. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    SciTech Connect

    Batygin, Konstantin; Stevenson, David J.

    2013-05-20

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M{sub Circled-Plus }, multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  7. Orbital circularization of a planet accreting disk gas: the formation of distant jupiters in circular orbits based on a core accretion model

    SciTech Connect

    Kikuchi, Akihiro; Higuchi, Arika; Ida, Shigeru E-mail: higuchia@geo.titech.ac.jp

    2014-12-10

    Recently, gas giant planets in nearly circular orbits with large semimajor axes (a ? 30-1000 AU) have been detected by direct imaging. We have investigated orbital evolution in a formation scenario for such planets, based on a core accretion model. (1) Icy cores accrete from planetesimals at ? 30 AU, (2) they are scattered outward by an emerging nearby gas giant to acquire highly eccentric orbits, and (3) their orbits are circularized through the accretion of disk gas in outer regions, where they spend most of their time. We analytically derived equations to describe the orbital circularization through gas accretion. Numerical integrations of these equations show that the eccentricity decreases by a factor of more than 5 while the planetary mass increases by a factor of 10. Because runaway gas accretion increases planetary mass by ?10-300, the orbits are sufficiently circularized. On the other hand, a is reduced at most only by a factor of two, leaving the planets in the outer regions. If the relative velocity damping by shock is considered, the circularization slows down, but is still efficient enough. Therefore, this scenario potentially accounts for the formation of observed distant jupiters in nearly circular orbits. If the apocenter distances of the scattered cores are larger than the disk sizes, their a shrink to a quarter of the disk sizes; the a-distribution of distant giants could reflect the outer edges of the disks in a similar way that those of hot jupiters may reflect inner edges.

  8. Lupus-TR-3b: A Low-Mass Transiting Hot Jupiter in the Galactic Plane?

    E-print Network

    David T. F. Weldrake; Daniel D. R. Bayliss; Penny D. Sackett; Brandon W. Tingley; Michael Gillon; Johny Setiawan

    2008-01-16

    We present a strong case for a transiting Hot Jupiter planet identified during a single-field transit survey towards the Lupus Galactic plane. The object, Lupus-TR-3b, transits a V=17.4 K1V host star every 3.91405d. Spectroscopy and stellar colors indicate a host star with effective temperature 5000 +/- 150K, with a stellar mass and radius of 0.87 +/- 0.04M_sun and 0.82 +/- 0.05R_sun, respectively. Limb-darkened transit fitting yields a companion radius of 0.89 +/- 0.07R_J and an orbital inclination of 88.3 +1.3/-0.8 deg. Magellan 6.5m MIKE radial velocity measurements reveal a 2.4 sigma K=114 +/- 25m/s sinusoidal variation in phase with the transit ephemeris. The resulting mass is 0.81 +/- 0.18M_J and density 1.4 +/- 0.4g/cm^3. Y-band PANIC image deconvolution reveal a V>=21 red neighbor 0.4'' away which, although highly unlikely, we cannot conclusively rule out as a blended binary with current data. However, blend simulations show that only the most unusual binary system can reproduce our observations. This object is very likely a planet, detected from a highly efficient observational strategy. Lupus-TR-3b constitutes the faintest ground-based detection to date, and one of the lowest mass Hot Jupiters known.

  9. Multiple planets or exomoons in Kepler hot Jupiter systems with transit timing variations?

    NASA Astrophysics Data System (ADS)

    Szabó, R.; Szabó, Gy. M.; Dálya, G.; Simon, A. E.; Hodosán, G.; Kiss, L. L.

    2013-05-01

    Aims: Hot Jupiters are thought to belong to single-planet systems. Somewhat surprisingly, some hot Jupiters have been reported to exhibit transit timing variations (TTVs). The aim of this paper is to identify the origin of these observations, identify possible periodic biases leading to false TTV detections, and refine the sample to a few candidates with likely dynamical TTVs. Methods: We present TTV frequencies and amplitudes of hot Jupiters in Kepler Q0-6 data with Fourier analysis and a frequency-dependent bootstrap calculation to assess the false alarm probability levels of the detections. Results: We identified 36 systems with TTV above four standard deviation confidence, about half of them exhibiting multiple TTV frequencies. Fifteen of these objects (HAT-P-7b, KOI-13, 127, 183, 188, 190, 196, 225, 254, 428, 607, 609, 684, 774, 1176) probably show TTVs due to a systematic observational effect: long cadence data sampling is regularly shifted transit-by-transit, interacting with the transit light curves, introducing a periodic bias, and leading to a stroboscopic period. For other systems, the activity and rotation of the host star can modulate light curves and explain the observed TTVs. By excluding the systems that were inadequately sampled, showed TTV periods related to the stellar rotation, or turned out to be false positives or suspects, we ended up with seven systems. Three of them (KOI-186, 897, 977) show the weakest stellar rotation features, and these are our best candidates for dynamically induced TTV variations. Conclusions: Those systems with periodic TTVs that we cannot explain with systematics from observation, stellar rotation, activity, or inadequate sampling, may be multiple systems or even exomoon hosts. Appendix A is available in electronic form at http://www.aanda.org

  10. Friends of Hot Jupiters III: An Infrared Spectroscopic Search for Low-Mass Stellar Companions

    E-print Network

    Piskorz, Danielle; Ngo, Henry; Muirhead, Philip S; Batygin, Konstantin; Crepp, Justin R; Hinkley, Sasha; Morton, Timothy D

    2015-01-01

    Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary techniques to search for stellar companions to known planet-hosting stars: radial velocity monitoring, adaptive optics imaging, and near-infrared spectroscopy. In this paper, we examine high-resolution K band infrared spectra of fifty stars hosting gas giant planets on short-period orbits. We use spectral fitting to search for blended lines due to the presence of cool stellar companions in the spectra of our target stars, where we are sensitive to companions with temperatures between 3500-5000 K and projected separations less than 100 AU in most systems. We identify eight systems with candidate low-mass companions, including one companion that was independently detected in our AO imaging survey. For systems with radial velocity accelerations, a spectroscopic non-detection rul...

  11. Obtaining the Mass and Radius of Extra-Solar Giant Planets

    NASA Technical Reports Server (NTRS)

    Castellano, Tim; Mead, Susan (Technical Monitor)

    1998-01-01

    The scientific utility and feasibility of detecting transits of the 9 known extrasolar planets is explored. A transit of a solar-like star by a Jupiter mass planet produces a 1% decrease in the amount of light received from the star. Transit observation will remove the ambiguity in the measurement of the planetary mass inherent in the radial velocity method and confirm the planet's existence. The 9 known planets have a 33% chance of producing at least one observable transit. Additional extrasolar planet detections from the radial velocity surveys will increase this probability to greater than 90%. The radius of the planet can be determined by the fractional decrease in light received during transit. The mass and radius may distinguish rocky or gas giant planets from brown dwarfs. The probability of detection, the transit signal size and duration, and predictions of the transit times (including errors) are calculated for circular and elliptical orbits. Observational limits are investigated and it is shown that small telescopes and existing detectors are adequate enough to achieve the 0.1% photometry necessary to detect transits of the known extrasolar planets.

  12. Deep in a star forming region with the VLT: looking for subJupiter mass objects

    E-print Network

    Comerón, Fernando

    Deep in a star forming region with the VLT: looking for sub­Jupiter mass objects F. Comer in star forming regions should have masses in the Jupiter­Saturn range and could be detectable in deep their existence and to test the input physics and chemistry of the models. Here I report on a deep JHK survey

  13. Magnitudes of selected stellar occultation candidates for Pluto and other planets, with new predictions for Mars and Jupiter

    NASA Technical Reports Server (NTRS)

    Sybert, C. B.; Bosh, A. S.; Sauter, L. M.; Elliot, J. L.; Wasserman, L. H.

    1992-01-01

    Occultation predictions for the planets Mars and Jupiter are presented along with BVRI magnitudes of 45 occultation candidates for Mars, Jupiter, Saturn, Uranus, and Pluto. Observers can use these magnitudes to plan observations of occultation events. The optical depth of the Jovian ring can be probed by a nearly central occultation on 1992 July 8. Mars occults an unusually red star in early 1993, and the occultations for Pluto involving the brightest candidates would possibly occur in the spring of 1992 and the fall of 1993.

  14. HAT-P-44b, HAT-P-45b, AND HAT-P-46b: Three transiting hot Jupiters in possible multi-planet systems

    SciTech Connect

    Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Csubry, Z.; Penev, K.; De Val-Borro, M.; Torres, G.; Latham, D. W.; Bieryla, A.; Béky, B.; Noyes, R. W.; Esquerdo, G. A.; Kovács, G.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Buchhave, L. A.; Fischer, D. A.; Everett, M.; Szklenár, T.; and others

    2014-06-01

    We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V = 13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49 M {sub J}, and radii of 1.24, 1.43, and 1.28 R {sub J}. The stellar hosts have masses of 0.94, 1.26, and 1.28 M {sub ?}. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, including the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494 ± 0.081, and a minimum mass of 4.0 M {sub J}. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5 ± 6.3 m s{sup –1} is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0 M {sub J}, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters.

  15. Enhancement of the Accretion of Jupiters Core by a Voluminous Low-Mass Envelope

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; D'angelo, Gennaro; Weidenschilling, Stuart John; Bodenheimer, Peter; Hubickyj, Olenka

    2013-01-01

    We present calculations of the early stages of the formation of Jupiter via core nucleated accretion and gas capture. The core begins as a seed body of about 350 kilometers in radius and orbits in a swarm of planetesimals whose initial radii range from 15 meters to 100 kilometers. We follow the evolution of the swarm by accounting for growth and fragmentation, viscous and gravitational stirring, and for drag-induced migration and velocity damping. Gas capture by the core substantially enhances the cross-section of the planet for accretion of small planetesimals. The dust opacity within the atmosphere surrounding the planetary core is computed self-consistently, accounting for coagulation and sedimentation of dust particles released in the envelope as passing planetesimals are ablated. The calculation is carried out at an orbital semi-major axis of 5.2 AU and an initial solids' surface density of 10/g/cm^2 at that distance. The results give a core mass of 7 Earth masses and an envelope mass of approximately 0.1 Earth mass after 500,000 years, at which point the envelope growth rate surpasses that of the core. The same calculation without the envelope gives a core mass of only 4 Earth masses.

  16. On the Mass-Period Correlation of the Extrasolar Planets

    E-print Network

    Shay Zucker; Tsevi Mazeh

    2002-02-22

    We report on a possible correlation between the masses and periods of the extrasolar planets, manifested as a paucity of massive planets with short orbital periods. Monte-Carlo simulations show the effect is significant, and is not solely due to an observational selection effect. We also show the effect is stronger than the one already implied by published models that assumed independent power-law distributions for the masses and periods of the extrasolar planets. Planets found in binary stellar systems may have an opposite correlation. The difference is highly significant despite the small number of planets in binary systems. We discuss the paucity of short-period massive planets in terms of some theories for the close-in giant planets. Almost all models can account for the deficit of massive planets with short periods, in particular the model that assumes migration driven by a planet-disk interaction, if the planet masses do not scale with their disk masses.

  17. A COLD NEPTUNE-MASS PLANET OGLE-2007-BLG-368Lb: COLD NEPTUNES ARE COMMON

    SciTech Connect

    Sumi, T.; Abe, F.; Fukui, A. E-mail: abe@stelab.nagoya-u.ac.j

    2010-02-20

    We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q = [9.5 +- 2.1] x 10{sup -5} via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the Microlensing Observations in Astrophysics survey, real-time light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns the stellar mass and distance at M{sub l} = 0.64{sup +0.21}{sub -0.26} M{sub sun} and D{sub l} = 5.9{sup +0.9}{sub -1.4} kpc, respectively, so the mass and separation of the planet are M{sub p} = 20{sup +7}{sub -8} M{sub +} and a = 3.3{sup +1.4}{sub -0.8} AU, respectively. This discovery adds another cold Neptune-mass planet to the planetary sample discovered by microlensing, which now comprises four cold Neptune/super-Earths, five gas giant planets, and another sub-Saturn mass planet whose nature is unclear. The discovery of these 10 cold exoplanets by the microlensing method implies that the mass ratio function of cold exoplanets scales as dN{sub pl}/dlog q {proportional_to} q {sup -0.7+}-{sup 0.2} with a 95% confidence level upper limit of n < -0.35 (where dN{sub pl}/dlog q {proportional_to} q{sup n} ). As microlensing is most sensitive to planets beyond the snow-line, this implies that Neptune-mass planets are at least three times more common than Jupiters in this region at the 95% confidence level.

  18. Parasitic Interference in Long Baseline Optical Interferometry: Requirements for Hot Jupiter-like Planet Detection

    NASA Astrophysics Data System (ADS)

    Matter, A.; Lopez, B.; Lagarde, S.; Danchi, W. C.; Robbe-Dubois, S.; Petrov, R. G.; Navarro, R.

    2009-12-01

    The observable quantities in optical interferometry, which are the modulus and the phase of the complex visibility, may be corrupted by parasitic fringes superimposed on the genuine fringe pattern. These fringes are due to an interference phenomenon occurring from stray light effects inside an interferometric instrument. We developed an analytical approach to better understand this phenomenon when stray light causes cross talk between beams. We deduced that the parasitic interference significantly affects the interferometric phase and thus the associated observables including the differential phase and the closure phase. The amount of parasitic flux coupled to the piston between beams appears to be very influential in this degradation. For instance, considering a point-like source and a piston ranging from ?/500 to ?/5 in the L band (? = 3.5 ?m), a parasitic flux of about 1% of the total flux produces a parasitic phase reaching at most one-third of the intrinsic phase. The piston, which can have different origins (instrumental stability, atmospheric perturbations, etc.), thus amplifies the effect of parasitic interference. According to the specifications of piston correction in space or at ground level (respectively ?/500 ? 2 nm and ?/30 ? 100 nm), the detection of hot Jupiter-like planets, one of the most challenging aims for current ground-based interferometers, limits parasitic radiation to about 5% of the incident intensity. This was evaluated by considering different types of hot Jupiter synthetic spectra. Otherwise, if no fringe tracking is used, the detection of a typical hot Jupiter-like system with a solar-like star would admit a maximum level of parasitic intensity of 0.01% for piston errors equal to ?/15. If the fringe tracking specifications are not precisely observed, it thus appears that the allowed level of parasitic intensity dramatically decreases and may prevent the detection. In parallel, the calibration of the parasitic phase by a reference star, at this accuracy level, seems very difficult. Moreover, since parasitic phase is an object-dependent quantity, the use of a hypothetical phase abacus, directly giving the parasitic phase from a given parasitic flux level, is also impossible. Some instrumental solutions, implemented at the instrument design stage for limiting or preventing this parasitic interference, appear to be crucial and are presented in this paper.

  19. PARASITIC INTERFERENCE IN LONG BASELINE OPTICAL INTERFEROMETRY: REQUIREMENTS FOR HOT JUPITER-LIKE PLANET DETECTION

    SciTech Connect

    Matter, A.; Lopez, B.; Lagarde, S.; Danchi, W. C.; Navarro, R.

    2009-12-01

    The observable quantities in optical interferometry, which are the modulus and the phase of the complex visibility, may be corrupted by parasitic fringes superimposed on the genuine fringe pattern. These fringes are due to an interference phenomenon occurring from stray light effects inside an interferometric instrument. We developed an analytical approach to better understand this phenomenon when stray light causes cross talk between beams. We deduced that the parasitic interference significantly affects the interferometric phase and thus the associated observables including the differential phase and the closure phase. The amount of parasitic flux coupled to the piston between beams appears to be very influential in this degradation. For instance, considering a point-like source and a piston ranging from lambda/500 to lambda/5 in the L band (lambda = 3.5 mum), a parasitic flux of about 1% of the total flux produces a parasitic phase reaching at most one-third of the intrinsic phase. The piston, which can have different origins (instrumental stability, atmospheric perturbations, etc.), thus amplifies the effect of parasitic interference. According to the specifications of piston correction in space or at ground level (respectively lambda/500 approx 2 nm and lambda/30 approx 100 nm), the detection of hot Jupiter-like planets, one of the most challenging aims for current ground-based interferometers, limits parasitic radiation to about 5% of the incident intensity. This was evaluated by considering different types of hot Jupiter synthetic spectra. Otherwise, if no fringe tracking is used, the detection of a typical hot Jupiter-like system with a solar-like star would admit a maximum level of parasitic intensity of 0.01% for piston errors equal to lambda/15. If the fringe tracking specifications are not precisely observed, it thus appears that the allowed level of parasitic intensity dramatically decreases and may prevent the detection. In parallel, the calibration of the parasitic phase by a reference star, at this accuracy level, seems very difficult. Moreover, since parasitic phase is an object-dependent quantity, the use of a hypothetical phase abacus, directly giving the parasitic phase from a given parasitic flux level, is also impossible. Some instrumental solutions, implemented at the instrument design stage for limiting or preventing this parasitic interference, appear to be crucial and are presented in this paper.

  20. Extrasolar Giant Planets: Masses and Luminosities from Insitu Formation Theories

    E-print Network

    Wuchterl, Günther

    Extrasolar Giant Planets: Masses and Luminosities from In­situ Formation Theories G¨unther Wuchterl direct detection of an extrasolar planet. The giant planet formation process is relatively slow Heidelberg, Germany Abstract. Their expected luminosities make young giant planets favorable for the first

  1. Planet-bound dark matter and the internal heat of Uranus, Neptune, and hot-Jupiter exoplanets

    E-print Network

    Stephen L. Adler

    2008-12-09

    We suggest that accretion of planet-bound dark matter by the Jovian planets, and by hot-Jupiter exoplanets, could be a significant source of their internal heat. The anomalously low internal heat of Uranus would then be explained if the collision believed to have tilted the axis of Uranus also knocked it free of most of its associated dark matter cloud. Our considerations focus on the efficient capture of non-self-annihilating dark matter, but could also apply to self-annihilating dark matter, provided the capture efficiency is small enough that the earth heat balance constraint is obeyed.

  2. Voyager 2 Jupiter Eruption Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie records an eruptive event in the southern hemisphere of Jupiter over a period of 8 Jupiter days. Prior to the event, an undistinguished oval cloud mass cruised through the turbulent atmosphere. The eruption occurs over avery short time at the very center of the cloud. The white eruptive material is swirled about by the internal wind patterns of the cloud. As a result of the eruption, the cloud then becomes a type of feature seen elsewhere on Jupiter known as 'spaghetti bowls'.

    As Voyager 2 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 8 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Violet filter around May 6, 1979. The spacecraft was about 50 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  3. COMPOSITION, CLOUDS, AND ORIGIN OF JUPITER'S ATMOSPHERE--A CASE FOR DEEP MULTIPROBES INTO GIANT PLANETS

    E-print Network

    Atreya, Sushil

    COMPOSITION, CLOUDS, AND ORIGIN OF JUPITER'S ATMOSPHERE-- A CASE FOR DEEP MULTIPROBES INTO GIANT of Jupiter and evolution of its atmosphere invoke large quantities of water, so that O/H = 1­3 × any the original carrier of heavy elements to Jupiter, determination of its abundance in the deep atmosphere

  4. MASSES, RADII, AND ORBITS OF SMALL KEPLER PLANETS: THE TRANSITION FROM GASEOUS TO ROCKY PLANETS

    E-print Network

    Seager, Sara

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements ...

  5. A Spitzer five-band analysis of the Jupiter-sized planet TrES-1

    SciTech Connect

    Cubillos, Patricio; Harrington, Joseph; Foster, Andrew S. D.; Lust, Nate B.; Hardy, Ryan A.; Bowman, M. Oliver; Madhusudhan, Nikku

    2014-12-10

    With an equilibrium temperature of 1200 K, TrES-1 is one of the coolest hot Jupiters observed by Spitzer. It was also the first planet discovered by any transit survey and one of the first exoplanets from which thermal emission was directly observed. We analyzed all Spitzer eclipse and transit data for TrES-1 and obtained its eclipse depths and brightness temperatures in the 3.6 ?m (0.083% ± 0.024%, 1270 ± 110 K), 4.5 ?m (0.094% ± 0.024%, 1126 ± 90 K), 5.8 ?m (0.162% ± 0.042%, 1205 ± 130 K), 8.0 ?m (0.213% ± 0.042%, 1190 ± 130 K), and 16 ?m (0.33% ± 0.12%, 1270 ± 310 K) bands. The eclipse depths can be explained, within 1? errors, by a standard atmospheric model with solar abundance composition in chemical equilibrium, with or without a thermal inversion. The combined analysis of the transit, eclipse, and radial-velocity ephemerides gives an eccentricity of e=0.033{sub ?0.031}{sup +0.015}, consistent with a circular orbit. Since TrES-1's eclipses have low signal-to-noise ratios, we implemented optimal photometry and differential-evolution Markov Chain Monte Carlo (MCMC) algorithms in our Photometry for Orbits, Eclipses, and Transits pipeline. Benefits include higher photometric precision and ?10 times faster MCMC convergence, with better exploration of the phase space and no manual parameter tuning.

  6. Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing

    SciTech Connect

    Gaudi, B; Bennett, D; Udalski, A; Gould, A; Christie, G; Maoz, D; Dong, S; McCormick, J; Szymanski, M; Tristram, P; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; DePoy, D; Han, C; Kaspi, S; Lee, C; Mallia, F; Natusch, T; Pogge, R; Park, B; Abe, F; Bond, I; Botzler, C; Fukui, A; Hearnshaw, J; Itow, Y; Kamiya, K; Korpela, A; Kilmartin, P; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N; Sako, T; Saito, T; Sato, S; Skuljan, L; Sullivan, D; Sumi, T; Sweatman, W; Yock, P; Albrow, M; Beaulieu, J; Burgdorf, M; Cook, K; Coutures, C; Dominik, M; Dieters, S; Fouque, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2007-11-08

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the first detection of a multiple-planet system with microlensing. We identify two planets with masses of {approx} 0.71 and {approx} 0.27 times the mass of Jupiter and orbital separations of {approx} 2.3 and {approx} 4.6 astronomical units orbiting a primary of mass {approx} 0.50 solar masses. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only 6 confirmed microlensing planet detections suggests that solar system analogs may be common.

  7. The occurrence and mass distribution of close-in super-Earths, Neptunes, and Jupiters.

    PubMed

    Howard, Andrew W; Marcy, Geoffrey W; Johnson, John Asher; Fischer, Debra A; Wright, Jason T; Isaacson, Howard; Valenti, Jeff A; Anderson, Jay; Lin, Doug N C; Ida, Shigeru

    2010-10-29

    The questions of how planets form and how common Earth-like planets are can be addressed by measuring the distribution of exoplanet masses and orbital periods. We report the occurrence rate of close-in planets (with orbital periods less than 50 days), based on precise Doppler measurements of 166 Sun-like stars. We measured increasing planet occurrence with decreasing planet mass (M). Extrapolation of a power-law mass distribution fitted to our measurements, df/dlogM = 0.39 M(-0.48), predicts that 23% of stars harbor a close-in Earth-mass planet (ranging from 0.5 to 2.0 Earth masses). Theoretical models of planet formation predict a deficit of planets in the domain from 5 to 30 Earth masses and with orbital periods less than 50 days. This region of parameter space is in fact well populated, implying that such models need substantial revision. PMID:21030652

  8. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. I. JUPITER-SATURN CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-05-01

    We carry out a series of high-resolution (1024 x 1024) hydrodynamical simulations to investigate the orbital evolution of Jupiter and Saturn embedded in a gaseous protostellar disk. Our work extends the results in the classical papers of Masset and Snellgrove and Morbidelli and Crida by exploring various surface density profiles ({sigma}), where {sigma} {proportional_to} r {sup -{alpha}}. The stability of the mean motion resonances (MMRs) caused by the convergent migration of the two planets is studied as well. Our results show that (1) the gap formation process of Saturn is greatly delayed by the tidal perturbation of Jupiter. These perturbations cause inward or outward runaway migration of Saturn, depending on the density profiles on the disk. (2) The convergent migration rate increases as {alpha} increases and the type of MMRs depends on {alpha} as well. When 0 < {alpha} < 1, the convergent migration speed of Jupiter and Saturn is relatively slow, thus they are trapped into 2:1 MMR. When {alpha}>4/3, Saturn passes through the 2:1 MMR with Jupiter and is captured into the 3:2 MMR. (3) The 3:2 MMR turns out to be unstable when the eccentricity of Saturn (e{sub s} ) increases too high. The critical value above which instability will set in is e{sub s} {approx} 0.15. We also observe that the two planets are trapped into 2:1 MMR after the break of 3:2 MMR. This process may provide useful information for the formation of orbital configuration between Jupiter and Saturn in the solar system.

  9. Jupiter: Satellites

    NASA Astrophysics Data System (ADS)

    Geissler, P.; Murdin, P.

    2003-04-01

    As befitting the king of the planets, JUPITER is orbited by an entourage of at least 39 natural satellites in addition to its faint rings, intense radiation belts and occasional temporary visitors from Earth and the outer solar system. Named after Zeus' lovers and other mythological companions, Jupiter's moons can be divided into four groups on the basis of their sizes and orbits (t...

  10. The SOPHIE search for northern extrasolar planets. VI. Three new hot Jupiters in multi-planet extrasolar systems

    NASA Astrophysics Data System (ADS)

    Moutou, C.; Hébrard, G.; Bouchy, F.; Arnold, L.; Santos, N. C.; Astudillo-Defru, N.; Boisse, I.; Bonfils, X.; Borgniet, S.; Delfosse, X.; Díaz, R. F.; Ehrenreich, D.; Forveille, T.; Gregorio, J.; Labrevoir, O.; Lagrange, A.-M.; Montagnier, G.; Montalto, M.; Pepe, F.; Sahlmann, J.; Santerne, A.; Ségransan, D.; Udry, S.; Vanhuysse, M.

    2014-03-01

    We present high-precision radial-velocity measurements of three solar-type stars: HD 13908, HD 159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD 13908 b is a planet with a minimum mass of 0.865 ± 0.035MJup on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25MJup . The star HD 159243 also has two detected companions with respective masses, periods, and eccentricities of Mp= 1.13 ± 0.05 and 1.9 ± 0.13MJup , P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258 has a planetary companion with a minimum mass of 1.068 ± 0.038MJup , an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD 13908, HD 159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258 is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets. Tables 5-8 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/563/A22Tables 5-7 are also available in electronic form at http://www.aanda.orgBased on observations collected with the SOPHIE spectrograph on the 1.93 m telescope at the Observatoire de Haute-Provence (CNRS), France, by the SOPHIE RPE Consortium (program PNP.CONS).

  11. Jupiter-like planets as dynamical barriers to inward-migrating super-Earths: a new understanding of the origin of Uranus and Neptune and predictions for extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Izidoro Da Costa, Andre'; Raymond, Sean

    2014-11-01

    Planets of 1-4 times Earth's size on orbits shorter than 100 days exist around 30-50% of all Sun-like stars. These ``hot super-Earths'' (or ``mini-Neptunes''), or their building blocks, might have formed on wider orbits and migrated inward due to interactions with the gaseous protoplanetary disk. The Solar System is statistically unusual in its lack of hot super-Earths. Here, we use a suite of dynamical simulations to show that gas-giant planets act as barriers to the inward migration of super-Earths initially placed on more distant orbits. Jupiter's early formation may have prevented Uranus and Neptune (and perhaps Saturn's core) from becoming hot super-Earths. It may actually have been crucial to the very formation of Uranus and Neptune. In fact, the large spin obliquities of these two planets argue that they experienced a stage of giant impacts from multi-Earth mass planetary embryos. We show that the dynamical barrier offered by Jupiter favors the mutual accretion of multiple migrating planetary embryos, favoring the formation of a few massive objects like Uranus and Neptune. Our model predicts that the populations of hot super-Earth systems and Jupiter-like planets should be anti-correlated: gas giants (especially if they form early) should be rare in systems with many hot super-Earths. Testing this prediction will constitute a crucial assessment of the validity of the migration hypothesis for the origin of close-in super-Earths.

  12. Polarization of Directly Imaged Young Giant Planets as a Probe of Mass, Rotation, and Clouds

    NASA Technical Reports Server (NTRS)

    Marley, Mark Scott; Sengupta, Sujan

    2012-01-01

    Young, hot gas giant planets at large separations from their primaries have been directly imaged around several nearby stars. More such planets will likely be detected by ongoing and new imaging surveys with instruments such as the Gemini Planet Imager (GPI). Efforts continue to model the spectra of these planets in order to constrain their masses, effective temperatures, composition, and cloud structure. One potential tool for analyzing these objects, which has received relatively less attention, is polarization. Linear polarization of gas giant exoplanets can arise from the combined influences of light scattering by atmospheric dust and a rotationally distorted shape. The oblateness of gas giant planet increases of course with rotation rate and for fixed rotation also rises with decreasing gravity. Thus young, lower mass gas giant planets with youthful inflated radii could easily have oblateness greater than that of Saturn s 10%. We find that polarizations of over 1% may easily be produced in the near-infrared in such cases. This magnitude of polarization may be measurable by GPI and other instruments. Thus if detected, polarization of a young Jupiter places constraints on the combination of its gravity, rotation rate, and degree of cloudiness. We will present results of our multiple scattering analysis coupled with a self-consistent dusty atmospheric models to demonstrate the range of polarizations that might be expected from resolved exoplanets and the range of parameter space that such observations may inform.

  13. Transiting Planets with LSST II. Period Detection of Planets Orbiting 1 Solar Mass Hosts

    E-print Network

    Jacklin, Savannah R; Pepper, Joshua; Stassun, Keivan G

    2015-01-01

    The Large Synoptic Survey Telescope (LSST) will photometrically monitor ~1 billion stars for ten years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al. (2015), LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiting a solar-mass star at a distance of 7 kpc, with orbital periods ranging from 0.5 to 20 d. We find that typical LSST observations will be able to reliably detect Hot Jupiters with periods shorter than ~3 d. At the same time, we find that the LSST deep drilling cadence is extremely powerful: the BLS algorithm successfully recovers at least 30% of sub-Saturn-size exoplanets with orbital periods as long as 20 d.

  14. Lupus-TR-3b: A Low-Mass Transiting Hot Jupiter in the Galactic Plane?

    E-print Network

    Weldrake, David T F; Sackett, Penny D; Tingley, Brandon W; Gillon, Michael; Setiawan, Johny

    2007-01-01

    We present a prime case for a transiting Hot Jupiter planet identified during a single-field transit survey towards the Lupus region of the Galactic plane. The object, Lupus-TR-3b, transits a V=17.4 K1V host star every 3.91405d. Spectroscopy and stellar colors indicate a host star with effective temperature 5000+/-150 K, with a stellar mass and radius of 0.87+/-0.04 Msun and 0.82+/-0.05 Rsun, respectively. Limb-darkened transit fitting yields a companion radius of 0.89+/-0.07 Rjup and an orbital inclination of 88.3{+1.3}{-0.8} deg. Magellan 6.5m MIKE radial velocity measurements reveal a 2.4 sigma K=114+/-25 m/s sinusoidal variation in phase with the transit ephemeris. The resulting mass is 0.81+/-0.18 Mjup and density 1.4+/-0.4 g/cm^3. Y-band PANIC image deconvolution reveal a V>=21 red neighbor 0.4'' away which, although highly unlikely, we cannot conclusively rule out as a blended binary with current data. However, no in-phase bisector variations are observed and blend simulations show that only the most u...

  15. The mass of dwarf planet Eris.

    PubMed

    Brown, Michael E; Schaller, Emily L

    2007-06-15

    The discovery of dwarf planet Eris was followed shortly by the discovery of its satellite, Dysnomia, but the satellite orbit, and thus the system mass, was not known. New observations with the Keck Observatory and the Hubble Space Telescopes show that Dysnomia has a circular orbit with a radius of 37,350 +/- 140 (1-sigma) kilometers and a 15.774 +/- 0.002 day orbital period around Eris. These orbital parameters agree with expectations for a satellite formed out of the orbiting debris left from a giant impact. The mass of Eris from these orbital parameters is 1.67 x 10(22) +/- 0.02 x 10(22) kilograms, or 1.27 +/- 0.02 that of Pluto. PMID:17569855

  16. Exceptional Stars Origins, Companions, Masses and Planets

    NASA Technical Reports Server (NTRS)

    Kulkarni, Shrinivas R.; Hansen, Bradley M. S.; Phinney, Sterl; vanKerkwijk, Martin H.; Vasisht, Gautam

    2004-01-01

    As SIM Interdisciplinary Scientist, we will study the formation, nature and planetary companions of the exotic endpoints of stellar evolution. Our science begins with stars evolving from asymptotic branch giants into white dwarfs. We will determine the parallax and orbital inclination of several iron-deficient post-AGB stars, who peculiar abundances and infrared excesses are evidence that they are accreting gas depleted of dust from a circumbinary disk. Measurement of the orbital inclination, companion mass arid parallax will provide critical constraints. One of these stars is a prime candidate for trying nulling observations, which should reveal light reflected from both the circumbinary and Roche disks. The circumbinary disks seem favorable sites for planet formation. Next, we will search for planets around white dwarfs, both survivors froni the main-sequence stage, and ones newly formed from the circumbinary disks of post-AGB binaries or in white dwarf mergers. Moving up in mass, we will measure the orbital reflex of OB/Be companions to pulsars, determine natal kicks and presupernova orbits, and expand the sample of well-determined neutron star masses. We will obtain the parallax of a transient X-ray binary, whose quiescent emission may be thermal emission from the neutron star, aiming for precise measurement of the neutron star radius. Finally, black holes. We will measure the reflex motions of the companion of what appear to be the most massive stellar black holes. The visual orbits will determine natal kicks, and test the assumptions underlying mass estimates made from the radial velocity curves, projected rotation, and ellipsoidal variations. In addition, we will attempt to observe the visual orbit of SS 433, as well as the proper motion of the emission line clumps in its relativistic jets. Additional information is included in the original document.

  17. Advanced Ion Mass Spectrometer for Giant Planet Ionospheres, Magnetospheres and Moons

    NASA Astrophysics Data System (ADS)

    Sittler, EC; Cooper, JF; Paschalidis, N.; Jones, SL; Rodriguez, M.; Ali, A.; Coplan, MA; Chornay, DJ; Sturner; Bateman, FB; Andre, N.; Fedorov, A.; Wurz, P.

    2015-10-01

    The Advanced Ion Composition Spectrometer (AIMS) has been under development from various NASA sources (NASA LWSID, NASA ASTID, NASA Goddard IRADs) to measure elemental, isotopic, and simple molecular composition abundances of 1 eV/e to 25 keV/e hot ions with wide field-of-view (FOV) in the 1 - 60 amu mass range at mass resolution M/?M ? 60 over a wide dynamic range of intensities and penetrating radiation background from the inner magnetospheres of Jupiter and Saturn to the outer magnetospheric boundary regions and the upstream solar wind. This instrument will work for both spinning spacecraft and 3-axis stabilized spacecraft with wide field-of-view capability in both cases. It will measure the ion velocity distribution functions (IVDF) for the individual ion species; ion velocity moments of the IVDF will give the fluid parameters (density, flow velocity and temperature) of the individual ion species. Outer planet mission applications are Io Observer, Jupiter Europa Orbiter/Europa Clipper, Enceladus Orbiter, and Uranus Orbiter as described in the decadal survey, but would also be valuable for inclusion on other missions to outer planet destinations such as Saturn- Titan and Neptune-Triton and for future missions to terrestrial planets, Venus and Mars, the Moon, asteroids, and comets, and of course for geospace applications to the Earth.

  18. Magnetically controlled mass-loss from extrasolar planets in close orbits

    NASA Astrophysics Data System (ADS)

    Owen, James E.; Adams, Fred C.

    2014-11-01

    We consider the role magnetic fields play in guiding and controlling mass-loss via evaporative outflows from exoplanets that experience UV irradiation. First, we present analytic results that account for planetary and stellar magnetic fields, along with mass-loss from both the star and planet. We then conduct series of numerical simulations for gas giant planets, and vary the planetary field strength, background stellar field strength, UV heating flux, and planet mass. These simulations show that the flow is magnetically controlled for moderate field strengths and even the highest UV fluxes, i.e. planetary surface fields BP ? 0.3 G and fluxes FUV ˜ 106 erg s-1. We thus conclude that outflows from all hot Jupiters with moderate surface fields are magnetically controlled. The inclusion of magnetic fields highly suppresses outflow from the night side of the planet. Only the magnetic field lines near the pole are open and allow outflow to occur. The fraction of open field lines depends sensitively on the strength (and geometry) of the background magnetic field from the star, along with the UV heating rate. The net effect of the magnetic field is to suppress the mass-loss rate by (approximately) an order of magnitude. Finally, some open field lines do not allow the flow to pass smoothly through the sonic point; flow along these streamlines does not reach a steady state, resulting in time-variable mass-loss.

  19. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    NASA Astrophysics Data System (ADS)

    Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.; Rowe, Jason F.; Jenkins, Jon M.; Bryson, Stephen T.; Latham, David W.; Howell, Steve B.; Gautier, Thomas N., III; Batalha, Natalie M.; Rogers, Leslie; Ciardi, David; Fischer, Debra A.; Gilliland, Ronald L.; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen; Huber, Daniel; Chaplin, William J.; Basu, Sarbani; Buchhave, Lars A.; Quinn, Samuel N.; Borucki, William J.; Koch, David G.; Hunter, Roger; Caldwell, Douglas A.; Van Cleve, Jeffrey; Kolbl, Rea; Weiss, Lauren M.; Petigura, Erik; Seager, Sara; Morton, Timothy; Johnson, John Asher; Ballard, Sarah; Burke, Chris; Cochran, William D.; Endl, Michael; MacQueen, Phillip; Everett, Mark E.; Lissauer, Jack J.; Ford, Eric B.; Torres, Guillermo; Fressin, Francois; Brown, Timothy M.; Steffen, Jason H.; Charbonneau, David; Basri, Gibor S.; Sasselov, Dimitar D.; Winn, Joshua; Sanchis-Ojeda, Roberto; Christiansen, Jessie; Adams, Elisabeth; Henze, Christopher; Dupree, Andrea; Fabrycky, Daniel C.; Fortney, Jonathan J.; Tarter, Jill; Holman, Matthew J.; Tenenbaum, Peter; Shporer, Avi; Lucas, Philip W.; Welsh, William F.; Orosz, Jerome A.; Bedding, T. R.; Campante, T. L.; Davies, G. R.; Elsworth, Y.; Handberg, R.; Hekker, S.; Karoff, C.; Kawaler, S. D.; Lund, M. N.; Lundkvist, M.; Metcalfe, T. S.; Miglio, A.; Silva Aguirre, V.; Stello, D.; White, T. R.; Boss, Alan; Devore, Edna; Gould, Alan; Prsa, Andrej; Agol, Eric; Barclay, Thomas; Coughlin, Jeff; Brugamyer, Erik; Mullally, Fergal; Quintana, Elisa V.; Still, Martin; Thompson, Susan E.; Morrison, David; Twicken, Joseph D.; Désert, Jean-Michel; Carter, Josh; Crepp, Justin R.; Hébrard, Guillaume; Santerne, Alexandre; Moutou, Claire; Sobeck, Charlie; Hudgins, Douglas; Haas, Michael R.; Robertson, Paul; Lillo-Box, Jorge; Barrado, David

    2014-02-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm-3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R ?. Larger planets evidently contain a larger fraction of low-density material (H, He, and H2O). Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology.

  20. Maximum likelihood method for estimating the mass and period distributions of extra-solar planets

    E-print Network

    Serge Tabachnik; Scott Tremaine

    2001-10-22

    We investigate the distribution of mass M and orbital period P of extra-solar planets, taking account of selection effects due to the limited velocity precision and duration of existing surveys. We fit the data on 63 planets to a power-law distribution of the form dn=CM^{-alpha}P^{-beta}(dM/M)(dP/P), and find alpha=0.12+-0.10, beta=-0.26+-0.06 for M<10M_J, where M_J is the Jupiter mass. The correlation coefficient between these two exponents is -0.32, indicating that uncertainties in the two distributions are coupled. We estimate that 3% of solar-type stars have companions in the range 1M_J

  1. Water contents of Earth-mass planets around M dwarfs

    NASA Astrophysics Data System (ADS)

    Tian, Feng; Ida, Shigeru

    2015-03-01

    Efforts to identify habitable extrasolar planets have focused on systems around M dwarfs, faint stars with less than half the solar mass. Habitable planets around M dwarfs are thought to be more plentiful and easier to detect than those orbiting Sun-like G dwarfs. However, unlike G dwarfs, M dwarfs experience a prolonged decline in luminosity early in their history, leading to an inward migration of the habitable zone to where planets may have lost their water through dissociation and hydrodynamic escape. Water-poor planets, such as Venus, are considered uninhabitable. In contrast, planets with too much water (>1 wt%) would lack continents, leading to climate instability and nutrient limitation problems. Here we combine a numerical planet population synthesis model with a model for water loss to show that the evolution of stellar luminosity leads to two types of planets of Earth-like mass (0.1 to 10 Earth masses) in the habitable zones around M dwarfs: ocean planets without continents, and desert planets, on which there are orders of magnitude less surface water than on Earth. According to our simulations, Earth-mass planets with Earth-like water contents are rare around M dwarfs and occur 10-100 times less frequently than around G dwarfs. We suggest that stars close to the size of the Sun should be the primary targets for detecting Earth-like planets.

  2. DETECTABILITY OF TRANSITING JUPITERS AND LOW-MASS ECLIPSING BINARIES IN SPARSELY SAMPLED PAN-STARRS-1 SURVEY DATA

    SciTech Connect

    Dupuy, Trent J.; Liu, Michael C.

    2009-10-20

    We present detailed simulations of the Pan-STARRS-1 (PS1) multi-epoch, multiband 3pi Survey in order to assess its potential yield of transiting planets and eclipsing binaries. This survey differs from dedicated transit surveys in that it will cover the entire northern sky but provide only sparsely sampled light curves. Since most eclipses would be detected at only a single epoch, the 3pi Survey will be most sensitive to deep eclipses (approx>0.10 mag) caused by Jupiters transiting M dwarfs and eclipsing stellar/substellar binaries. The survey will measure parallaxes for the approx4 x 10{sup 5} stars within 100 pc, which will enable a volume-limited eclipse search, reducing the number of astrophysical false positives compared with previous magnitude-limited searches. Using the best available empirical data, we constructed a model of the extended solar neighborhood that includes stars, brown dwarfs, and a realistic binary population. We computed the yield of deeply eclipsing systems using both a semianalytic and a full Monte Carlo approach. We examined statistical tests for detecting single-epoch eclipses in sparsely sampled data and assessed their vulnerability to false positives due to stellar variability. Assuming a short-period planet frequency of 0.5% for M dwarfs, our simulations predict that about a dozen transiting Jupiters around low-mass stars (M {sub *} < 0.3 M {sub sun}) within 100 pc are potentially detectable in the PS1 3pi Survey, along with approx300 low-mass eclipsing binaries (both component masses <0.5 M {sub sun}), including approx10 eclipsing field brown dwarfs. Extensive follow-up observations would be required to characterize these candidate eclipsing systems, thereby enabling comprehensive tests of structural models and novel insights into the planetary architecture of low-mass stars.

  3. Methane Planets and their Mass-Radius Relation

    E-print Network

    Helled, Ravit; Vos, Eran

    2015-01-01

    Knowledge of both the mass and radius of an exoplanet allows us to estimate its mean density, and therefore, its composition. Exoplanets seem to fill a very large parameter space in terms of mass and composition, and unlike the solar-system's planets, exoplanets also have intermediate masses (~5-50 M_Earth) with various densities. In this letter, we investigate the behavior of the Mass-Radius relation for methane (CH_4) planets and show that when methane planets are massive enough (M_planet > ~15 M_Earth) the methane can dissociate and lead to a differentiated planet with a carbon core, a methane envelope, and a hydrogen atmosphere. The contribution of a rocky core to the behavior of CH_4 planet is considered as well. We also develop interior models for several detected intermediate-mass planets that could, in principle, be methane/methane-rich planets. The example of methane planets emphasizes the complexity of the Mass-Radius relation and the challenge in inferring the planetary composition uniquely.

  4. Hot Jupiters and cool stars

    SciTech Connect

    Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

    2014-10-10

    Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M {sub ?}), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

  5. Astrometric observations of the faint satellites of Jupiter and minor planets, 1974-1977

    NASA Technical Reports Server (NTRS)

    Benedict, G. R.; Shelus, P. J.; Mulholland, J. D.

    1978-01-01

    Precise positions of the faint satellites VI-XII of Jupiter during the 1974 opposition, and for Jupiter XIII during the 1976-1977 and 1977-1978 oppositions, have been obtained from plates taken with the 2.1-m Otto Struve reflector of the McDonald Observatory by the use of a new quasi-automatic plate measurement and reduction procedure on a PDS microdensitometer. Observations of selected asteroids, including two of 1977 UB (Chiron) are given also.

  6. Detecting Earth-Mass Planets with Gravitational Microlensing

    E-print Network

    David P. Bennett; Sun Hong Rhie

    1996-03-30

    We show that Earth mass planets orbiting stars in the Galactic disk and bulge can be detected by monitoring microlensed stars in the Galactic bulge. The star and its planet act as a binary lens which generates a lightcurve which can differ substantially from the lightcurve due only to the star itself. We show that the planetary signal remains detectable for planetary masses as small as an Earth mass when realistic source star sizes are included in the lightcurve calculation. These planets are detectable if they reside in the ``lensing zone" which is centered between 1 and 4 AU from the lensing star and spans about a factor of 2 in distance. If we require a minimum deviation of 4\\% from the standard point-lens microlensing lightcurve, then we find that more than 2\\% of all $\\mearth$ planets and 10\\% of all $10\\mearth$ in the lensing zone can be detected. If a third of all lenses have no planets, a third have $1\\mearth$ planets and the remaining third have $10\\mearth$ planets then we estimate that an aggressive ground based microlensing planet search program could find one earth mass planet and half a dozen $10\\mearth$ planets per year.

  7. Planetary populations in the mass-period diagram: A statistical treatment of exoplanet formation and the role of planet traps

    SciTech Connect

    Hasegawa, Yasuhiro; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2013-11-20

    The rapid growth of observed exoplanets has revealed the existence of several distinct planetary populations in the mass-period diagram. Two of the most surprising are (1) the concentration of gas giants around 1 AU and (2) the accumulation of a large number of low-mass planets with tight orbits, also known as super-Earths and hot Neptunes. We have recently shown that protoplanetary disks have multiple planet traps that are characterized by orbital radii in the disks and halt rapid type I planetary migration. By coupling planet traps with the standard core accretion scenario, we showed that one can account for the positions of planets in the mass-period diagram. In this paper, we demonstrate quantitatively that most gas giants formed at planet traps tend to end up around 1 AU, with most of these being contributed by dead zones and ice lines. We also show that a large fraction of super-Earths and hot Neptunes are formed as 'failed' cores of gas giants—this population being constituted by comparable contributions from dead zone and heat transition traps. Our results are based on the evolution of forming planets in an ensemble of disks where we vary only the lifetimes of disks and their mass accretion rates onto the host star. We show that a statistical treatment of the evolution of a large population of planetary cores caught in planet traps accounts for the existence of three distinct exoplanetary populations—the hot Jupiters, the more massive planets around r = 1 AU, and the short-period super-Earths and hot Neptunes. There are very few populations that feed into the large orbital radii characteristic of the imaged Jovian planet, which agrees with recent surveys. Finally, we find that low-mass planets in tight orbits become the dominant planetary population for low-mass stars (M {sub *} ? 0.7 M {sub ?}).

  8. Refining Mass Measurements of Kepler Planets with Keck/HIRES.

    NASA Astrophysics Data System (ADS)

    Isaacson, Howard T.; Marcy, Geoffrey W.; Howard, Andrew

    2015-12-01

    We present improved radial velocity mass measurements from Keck/HIRES for exoplanets detected by NASA’s Kepler Mission. Since Kepler’s launch 6 years ago, ~30 planetary systems have been monitored with radial velocities, resulting in measured masses for many planets between 1.0 and 4.0 Earth radii. The resulting planet masses have been used to determine the transition between planets with a rocky interior and those with a lower density interior which requiring significant H/He atmospheres. We provide updated masses and densities for those planets published in Marcy et al (2014) based on two additional observing seasons with HIRES of the Kepler field. These radial velocities also reveal non-transiting planets in systems with previously found transiting planets. One such system has a non-transiting planet with a period between two transiting planets, providing a constraint on the co-planarity of the system. Finally, we provide an updated mass-radius relation, showing the distinction between planets that must have a substantial iron-silicate interior, and those requiring significant contributions from volatiles such as hydrogen and helium.

  9. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Unruh, Y. C.; Koskinen, T. T.; Sanz-Forcada, J.

    2015-04-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - ? Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale the EUV regions of the solar spectrum based upon stellar X-ray emission. This new method produces an outcome in terms of the planet's neutral upper atmosphere very similar to that obtained using a detailed coronal model of the host star. Our results indicate that in planets subjected to radiation from active stars, the transition from Jeans escape to a regime of hydrodynamic escape at the top of the atmosphere occurs at larger orbital distances than for planets around low activity stars (such as the Sun).

  10. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    E-print Network

    Marcy, Geoffrey W; Howard, Andrew W; Rowe, Jason F; Jenkins, Jon M; Bryson, Stephen T; Latham, David W; Howell, Steve B; Gautier, Thomas N; Batalha, Natalie M; Rogers, Leslie A; Ciardi, David; Fischer, Debra A; Gilliland, Ronald L; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen; Huber, Daniel; Chaplin, William J; Basu, Sarbani; Buchhave, Lars A; Quinn, Samuel N; Borucki, William J; Koch, David G; Hunter, Roger; Caldwell, Douglas A; Van Cleve, Jeffrey; Kolbl, Rea; Weiss, Lauren M; Petigura, Erik; Seager, Sara; Morton, Timothy; Johnson, John Asher; Ballard, Sarah; Burke, Chris; Cochran, William D; Endl, Michael; MacQueen, Phillip; Everett, Mark E; Lissauer, Jack J; Ford, Eric B; Torres, Guillermo; Fressin, Francois; Brown, Timothy M; Steffen, Jason H; Charbonneau, David; Basri, Gibor S; Sasselov, Dimitar D; Winn, Joshua; Sanchis-Ojeda, Roberto; Christiansen, Jessie; Adams, Elisabeth; Henze, Christopher; Dupree, Andrea; Fabrycky, Daniel C; Fortney, Jonathan J; Tarter, Jill; Holman, Matthew J; Tenenbaum, Peter; Shporer, Avi; Lucas, Philip W; Welsh, William F; Orosz, Jerome A; Bedding, T R; Campante, T L; Davies, G R; Elsworth, Y; Handberg, R; Hekker, S; Karoff, C; Kawaler, S D; Lund, M N; Lundkvist, M; Metcalfe, T S; Miglio, A; Aguirre, V Silva; Stello, D; White, T R; Boss, Alan; Devore, Edna; Gould, Alan; Prsa, Andrej; Agol, Eric; Barclay, Thomas; Coughlin, Jeff; Brugamyer, Erik; Mullally, Fergal; Quintana, Elisa V; Still, Martin; hompson, Susan E; Morrison, David; Twicken, Joseph D; Désert, Jean-Michel; Carter, Josh; Crepp, Justin R; Hébrard, Guillaume; Santerne, Alexandre; Moutou, Claire; Sobeck, Charlie; Hudgins, Douglas; Haas, Michael R; Robertson, Paul; Lillo-Box, Jorge; Barrado, David

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities for all of the transiting planets (41 of 42 have a false-positive probability under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than 3X the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify 6 planets with densities above 5 g/cc, suggesting a mostly rocky interior f...

  11. A STELLAR-MASS-DEPENDENT DROP IN PLANET OCCURRENCE RATES

    SciTech Connect

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-10

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R {sub ?}) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ?10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  12. A Stellar-mass-dependent Drop in Planet Occurrence Rates

    NASA Astrophysics Data System (ADS)

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-01

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R ?) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ~10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  13. Methane Planets and Their Mass-Radius Relation

    NASA Astrophysics Data System (ADS)

    Helled, Ravit; Podolak, Morris; Vos, Eran

    2015-06-01

    Knowledge of both the mass and radius of an exoplanet allows us to estimate its mean density, and therefore its composition. Exoplanets seem to fill a very large parameter space in terms of mass and composition, and unlike the solar-system’s planets, exoplanets also have intermediate masses (˜5-50 {{M}\\oplus }) with various densities. In this Letter, we investigate the behavior of the mass-radius relation for methane (CH4) planets and show that when methane planets are massive enough ({{M}p} ? 15 M\\oplus ), the methane can dissociate and lead to a differentiated planet with a carbon core, a methane envelope, and a hydrogen atmosphere. The contribution of a rocky core to the behavior of a CH4 planet is also considered. We also develop interior models for several detected intermediate-mass planets that could, in principle, be methane/methane-rich planets. The example of methane planets emphasizes the complexity of the mass-radius relation and the challenge involved in uniquely inferring the planetary composition.

  14. Exotic Earths: Forming Habitable Worlds with Giant Planet Migration

    E-print Network

    Sean N. Raymond; Avi M. Mandell; Steinn Sigurdsson

    2006-09-08

    Close-in giant planets (e.g. ``Hot Jupiters'') are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth mass planets also form interior to the migrating Jovian planet, analogous to recently-discovered ``Hot Earths''. Very water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the Habitable Zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.

  15. Exotic Earths: forming habitable worlds with giant planet migration.

    PubMed

    Raymond, Sean N; Mandell, Avi M; Sigurdsson, Steinn

    2006-09-01

    Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets. PMID:16960000

  16. AN UNDERSTANDING OF THE SHOULDER OF GIANTS: JOVIAN PLANETS AROUND LATE K DWARF STARS AND THE TREND WITH STELLAR MASS

    SciTech Connect

    Gaidos, Eric; Fischer, Debra A.; Mann, Andrew W.; Howard, Andrew W.

    2013-07-01

    Analyses of exoplanet statistics suggest a trend of giant planet occurrence with host star mass, a clue to how planets like Jupiter form. One missing piece of the puzzle is the occurrence around late K dwarf stars (masses of 0.5-0.75 M{sub Sun} and effective temperatures of 3900-4800 K). We analyzed four years of Doppler radial velocity (RVs) data for 110 late K dwarfs, one of which hosts two previously reported giant planets. We estimate that 4.0% {+-} 2.3% of these stars have Saturn-mass or larger planets with orbital periods <245 days, depending on the planet mass distribution and RV variability of stars without giant planets. We also estimate that 0.7% {+-} 0.5% of similar stars observed by Kepler have giant planets. This Kepler rate is significantly (99% confidence) lower than that derived from our Doppler survey, but the difference vanishes if only the single Doppler system (HIP 57274) with completely resolved orbits is considered. The difference could also be explained by the exclusion of close binaries (without giant planets) from the Doppler but not Kepler surveys, the effect of long-period companions and stellar noise on the Doppler data, or an intrinsic difference between the two populations. Our estimates for late K dwarfs bridge those for solar-type stars and M dwarfs, and support a positive trend with stellar mass. Small sample size precludes statements about finer structure, e.g., a ''shoulder'' in the distribution of giant planets with stellar mass. Future surveys such as the Next Generation Transit Survey and the Transiting Exoplanet Satellite Survey will ameliorate this deficiency.

  17. On the Luminosity of Young Jupiters

    E-print Network

    M. S. Marley; J. J. Fortney; O. Hubickyj; P. Bodenheimer; J. J. Lissauer

    2006-09-27

    Traditional thermal evolution models of giant planets employ arbitrary initial conditions selected more for computational expediency than physical accuracy. Since the initial conditions are eventually forgotten by the evolving planet, this approach is valid for mature planets, if not young ones. To explore the evolution at young ages of jovian mass planets we have employed model planets created by one implementation of the core accretion mechanism as initial conditions for evolutionary calculations. We find that young jovian planets are smaller, cooler, and several to 100 times less luminous than predicted by earlier models. Furthermore the time interval during which the young jupiters are fainter than expected depends on the mass of planet. Jupiter mass planets (1 M_J) align with the conventional model luminosity in as little at 20 million years, but 10 M_J planets can take up to 1 billion years to match commonly cited luminosities, given our implementation of the core accretion mechanism. If our assumptions, especially including our treatment of the accretion shock, are correct, then young jovian planets are substantially fainter at young ages than currently believed. These results have important consequences both for detection strategies and for assigning masses to young jovian planets based on observed luminosities.

  18. RV survey for planets of brown dwarfs and very low-mass stars in ChaI

    E-print Network

    Viki Joergens; Ralph Neuhäuser

    2003-06-23

    We have carried out a radial velocity (RV) search for planets and brown dwarf companions to very young (1-10Myr) brown dwarfs and very low-mass stars in the ChaI star forming region. This survey has been carried out with the high-resolution Echelle spectrograph UVES at the VLT. It is sensitive down to Jupiter mass planets. Out of the twelve monitored very low-mass stars and brown dwarfs, ten have constant RVs in the presented RV survey. This hints at a small multiplicity fraction of the studied population of brown dwarfs and very low-mass stars in ChaI at small separations. Upper limits for the mass Msini of possible companions have been estimated to range between 0.1 and 1.5 Jupiter masses. However, two very low-mass stars in ChaI show significant RV variations. The nature of these variations is still unclear. If caused by orbiting objects the recorded variability amplitudes would correspond to planets of the order of a few Jupiter masses. Furthermore, as a by-product of the RV survey for companions, we have studied the kinematics of the brown dwarfs in ChaI. Precise kinematic studies of young brown dwarfs are interesting in the context of the question if brown dwarfs are formed by the recently proposed ejection scenario. We have found that the RV dispersion of brown dwarfs in ChaI is only 2.2 km\\s giving a first empirical upper limit for possible ejection velocities.

  19. Terrestrial planet formation in a protoplanetary disk with a local mass depletion: A successful scenario for the formation of Mars

    SciTech Connect

    Izidoro, A.; Winter, O. C.; Haghighipour, N.; Tsuchida, M. E-mail: nader@ifa.hawaii.edu

    2014-02-10

    Models of terrestrial planet formation for our solar system have been successful in producing planets with masses and orbits similar to those of Venus and Earth. However, these models have generally failed to produce Mars-sized objects around 1.5 AU. The body that is usually formed around Mars' semimajor axis is, in general, much more massive than Mars. Only when Jupiter and Saturn are assumed to have initially very eccentric orbits (e ? 0.1), which seems fairly unlikely for the solar system, or alternately, if the protoplanetary disk is truncated at 1.0 AU, simulations have been able to produce Mars-like bodies in the correct location. In this paper, we examine an alternative scenario for the formation of Mars in which a local depletion in the density of the protosolar nebula results in a non-uniform formation of planetary embryos and ultimately the formation of Mars-sized planets around 1.5 AU. We have carried out extensive numerical simulations of the formation of terrestrial planets in such a disk for different scales of the local density depletion, and for different orbital configurations of the giant planets. Our simulations point to the possibility of the formation of Mars-sized bodies around 1.5 AU, specifically when the scale of the disk local mass-depletion is moderately high (50%-75%) and Jupiter and Saturn are initially in their current orbits. In these systems, Mars-analogs are formed from the protoplanetary materials that originate in the regions of disk interior or exterior to the local mass-depletion. Results also indicate that Earth-sized planets can form around 1 AU with a substantial amount of water accreted via primitive water-rich planetesimals and planetary embryos. We present the results of our study and discuss their implications for the formation of terrestrial planets in our solar system.

  20. The Photoeccentric Effect and Proto-hot Jupiters. II. KOI-1474.01, a Candidate Eccentric Planet Perturbed by an Unseen Companion

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, John Asher; Morton, Timothy D.; Crepp, Justin R.; Fabrycky, Daniel C.; Murray-Clay, Ruth A.; Howard, Andrew W.

    2012-12-01

    The exoplanets known as hot Jupiters—Jupiter-sized planets with periods of less than 10 days—likely are relics of dynamical processes that shape all planetary system architectures. Socrates et al. argued that high eccentricity migration (HEM) mechanisms proposed for situating these close-in planets should produce an observable population of highly eccentric proto-hot Jupiters that have not yet tidally circularized. HEM should also create failed-hot Jupiters, with periapses just beyond the influence of fast circularization. Using the technique we previously presented for measuring eccentricities from photometry (the "photoeccentric effect"), we are distilling a collection of eccentric proto- and failed-hot Jupiters from the Kepler Objects of Interest (KOI). Here, we present the first, KOI-1474.01, which has a long orbital period (69.7340 days) and a large eccentricity e = 0.81+0.10 -0.07, skirting the proto-hot Jupiter boundary. Combining Kepler photometry, ground-based spectroscopy, and stellar evolution models, we characterize host KOI-1474 as a rapidly rotating F star. Statistical arguments reveal that the transiting candidate has a low false-positive probability of 3.1%. KOI-1474.01 also exhibits transit-timing variations of the order of an hour. We explore characteristics of the third-body perturber, which is possibly the "smoking-gun" cause of KOI-1474.01's large eccentricity. We use the host star's period, radius, and projected rotational velocity to measure the inclination of the stellar spin. Comparing KOI 1474.01's inclination, we find that its orbit is marginally consistent with being aligned with the stellar spin axis, although a reanalysis is warranted with future additional data. Finally, we discuss how the number and existence of proto-hot Jupiters will not only demonstrate that hot Jupiters migrate via HEM, but also shed light on the typical timescale for the mechanism.

  1. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. II. KOI-1474.01, A CANDIDATE ECCENTRIC PLANET PERTURBED BY AN UNSEEN COMPANION

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher; Morton, Timothy D.; Crepp, Justin R.; Fabrycky, Daniel C.; Howard, Andrew W.

    2012-12-20

    The exoplanets known as hot Jupiters-Jupiter-sized planets with periods of less than 10 days-likely are relics of dynamical processes that shape all planetary system architectures. Socrates et al. argued that high eccentricity migration (HEM) mechanisms proposed for situating these close-in planets should produce an observable population of highly eccentric proto-hot Jupiters that have not yet tidally circularized. HEM should also create failed-hot Jupiters, with periapses just beyond the influence of fast circularization. Using the technique we previously presented for measuring eccentricities from photometry (the ''photoeccentric effect''), we are distilling a collection of eccentric proto- and failed-hot Jupiters from the Kepler Objects of Interest (KOI). Here, we present the first, KOI-1474.01, which has a long orbital period (69.7340 days) and a large eccentricity e 0.81{sup +0.10}{sub -0.07}, skirting the proto-hot Jupiter boundary. Combining Kepler photometry, ground-based spectroscopy, and stellar evolution models, we characterize host KOI-1474 as a rapidly rotating F star. Statistical arguments reveal that the transiting candidate has a low false-positive probability of 3.1%. KOI-1474.01 also exhibits transit-timing variations of the order of an hour. We explore characteristics of the third-body perturber, which is possibly the ''smoking-gun'' cause of KOI-1474.01's large eccentricity. We use the host star's period, radius, and projected rotational velocity to measure the inclination of the stellar spin. Comparing KOI 1474.01's inclination, we find that its orbit is marginally consistent with being aligned with the stellar spin axis, although a reanalysis is warranted with future additional data. Finally, we discuss how the number and existence of proto-hot Jupiters will not only demonstrate that hot Jupiters migrate via HEM, but also shed light on the typical timescale for the mechanism.

  2. Atmospheric circulations of terrestrial planets orbiting low mass stars

    NASA Astrophysics Data System (ADS)

    Edson, Adam Robert

    Atmospheres of planets orbiting low mass stars have properties unlike those typically studied by climatologists. One of the most glaring differences is that the rotation is "trapped" for planets orbiting within the habitable zone of the star. This lack of a typical "day" changes these planets' dynamics. Previous work includes that of Gareth Williams and Manoj Joshi. Joshi discussed planets with 10-day orbits only. Williams focused on planets with differing rotation rates, but still rotating relative to their star. Here, tidally locked planets with a variety of orbital periods ranging from 1 to 100 days are discussed. The GENESIS model is used to simulate these planets, and the data are analyzed for waves, energy fluxes, and habitability. The major components of the energy fluxes are the mean meridional circulation (i.e., the Hadley cell) and stationary eddies in the form of a wave number 1 stationary Rossby wave. A transition point in the atmospheric circulation is identified for orbital periods between 100 hours and 101 hours for dry planets. For the wet planets, the transition occurs near 96-hour rotation period. This transition occurs when the Rossby radius of deformation approaches the planet's radius and is associated with the increasing importance of the wave number two stationary eddy as the Rossby radius approaches the planetary radius. The most habitable dry planet is found to be the 2400-hour orbiter. For the wet planets, the 24-hour rotator is most habitable. The most habitable wet planet is the 24-hour rotator, with the least habitable wet planet being the 2400-hour rotator. The difference in the rotation period of the most habitable planets between the dry planets and the wet planets is caused by the availability of water vapor as a greenhouse gas, the added heat transport through sea ice movement, and the larger heat capacity for the wet planets. When realistic planets are modeled, the habitable surface area and average surface temperature is dependent on the landmass distribution. Large landmasses illuminated by the star draw down the carbon dioxide concentration in the atmosphere, which decreases the habitable area.

  3. The SOPHIE search for northern extrasolar planets. V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars

    NASA Astrophysics Data System (ADS)

    Boisse, I.; Pepe, F.; Perrier, C.; Queloz, D.; Bonfils, X.; Bouchy, F.; Santos, N. C.; Arnold, L.; Beuzit, J.-L.; Díaz, R. F.; Delfosse, X.; Eggenberger, A.; Ehrenreich, D.; Forveille, T.; Hébrard, G.; Lagrange, A.-M.; Lovis, C.; Mayor, M.; Moutou, C.; Naef, D.; Santerne, A.; Ségransan, D.; Sivan, J.-P.; Udry, S.

    2012-09-01

    We present radial-velocity measurements obtained in one of a number of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Haute-Provence Observatory. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years. Two new Jupiter-analog candidates are reported to orbit the bright stars HD 150706 and HD 222155 in 16.1 yr and 10.9 yr at 6.7-1.4+4.0 AU and 5.1-0.7+0.6 AU, and to have minimum masses of 2.71-0.66+1.14 MJup and 1.90-0.53+0.67 MJup, respectively. Using the measurements from ELODIE and SOPHIE, we refine the parameters of the long-period planets HD 154345b and HD 89307b, and publish the first reliable orbit for HD 24040b. This last companion has a minimum mass of 4.01 ± 0.49 MJup orbiting its star in 10.0 yr at 4.92 ± 0.38 AU. Moreover, the data provide evidence of a third bound object in the HD 24040 system. With a surrounding dust debris disk, HD 150706 is an active G0 dwarf for which we partially corrected the effect of the stellar spot on the SOPHIE radial-velocities. In contrast, HD 222155 is an inactive G2V star. In the SOPHIE measurements, an instrumental effect could be characterized and partly corrected. On the basis of the previous findings of Lovis and collaborators and since no significant correlation between the radial-velocity variations and the activity index are found in the SOPHIE data, these variations are not expected to be only due to stellar magnetic cycles. Finally, we discuss the main properties of this new population of long-period Jupiter-mass planets, which for the moment consists of fewer than 20 candidates. These stars are preferential targets either for direct-imaging or astrometry follow-up surveys to constrain the system parameters and for higher-precision radial-velocity searches for lower mass planets, aiming to find a solar system twin. In the Appendix, we determine the relation that defines the radial-velocity offset between the ELODIE and SOPHIE spectrographs. Based on observations made with the ELODIE and the SOPHIE spectrographs on the 1.93-m telescope at Observatoire de Haute-Provence (OHP, CNRS/OAMP), France (program 07A.PNP.CONS) and on spectral data retrieved from the ELODIE archive at OHP. Tables A.1-A.10 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/545/A55

  4. High-dispersion spectroscopy of extrasolar planets: from CO in hot Jupiters to O2 in exo-Earths.

    PubMed

    Snellen, Ignas

    2014-04-28

    Ground-based high-dispersion spectroscopy could reveal molecular oxygen as a biomarker gas in the atmospheres of twin-Earths transiting red dwarf stars within the next 25 years. The required contrasts are only a factor of 3 lower than that already achieved for carbon monoxide in hot Jupiter atmospheres today but will need much larger telescopes because the target stars will be orders of magnitude fainter. If extraterrestrial life is very common and can therefore be found on planets around the most nearby red dwarf stars, it may be detectable via transmission spectroscopy with the next-generation extremely large telescopes. However, it is likely that significantly more collecting area is required for this. This can be achieved through the development of low-cost flux collector technology, which combines a large collecting area with a low but sufficient image quality for high-dispersion spectroscopy of bright stars. PMID:24664914

  5. Testing the correlation between low mass planets and debris disks

    NASA Astrophysics Data System (ADS)

    Kalas, Paul

    2014-10-01

    The number of dusty debris disks has increased across all spectral types through recent infrared surveys. This has provided greater overlap with stars known to host extrasolar planets via RV surveys. New studies have therefore investigated how the different properties of host stars, exoplanets, and debris disks may be correlated, with the objective of giving empirical support to competing theories of planet formation and evolution. One such emerging correlation is that stars with only low mass planets are more likely to host prominent debris disks than stars that have at least one giant planet. If true, then M dwarfs should have abundant debris disks given that they more frequently have low mass planetary systems. However, the information needed to critically test these ideas is lacking. For most systems, the presence of an outer planet with >30 Earth masses has not been observationally tested, nor are there many M dwarf debris disks available for detailed scrutiny. Here we propose to use STIS coronagraphy to image for the first time the debris disks around three nearby stars in optical scattered light. Searching for sharp dust belt structures indirectly tests for the existence of outer planets that are otherwise undetectable by RV or adaptive optics planet searches. Moreover, two of our target stars are the most recently discovered M dwarf debris disks, both closer to the Sun than AU Mic. The scattered light observations of these two targets would present a major advance in characterizing how M dwarf debris disks co-evolve with planets under different stellar environments.

  6. Giant Planets

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.

    Beyond the inner solar system's terrestrial planets, with their compact orbits and rock -metal compositions, lies the realm of the outer solar system and the giant planets. Here the distance between planets jumps by an order of magnitude relative to the spacing of the terrestrial planets, and the masses of the giants are one to two orders of magnitude greater than Venus and Earth - the largest terrestrial bodies. Composition changes as well, since the giant planets are largely gaseous, with inferred admixtures of ice, rock, and metal, while the terrestrial planets are essentially pure rock and metal. The giant planets have many more moons than do the terrestrial planets, and the range of magnetic field strengths is larger in the outer solar system. It is the giant planets that sport rings, ranging from the magnificent ones around Saturn to the variable ring arcs of Neptune. Were it not for the fact that only Earth supports abundant life (with life possibly existing, but not proved to exist, in the martian crust and liquid water regions underneath the ice of Jupiter's moon Europa), the terrestrial planets would pale in interest next to the giant planets for any extraterrestrial visitor.

  7. Fomalhaut's Debris Disk and Planet: Constraining the Mass of Formalhaut B from Disk Morphology

    NASA Technical Reports Server (NTRS)

    Chiang, E.; Kite, E.; Kalas, P.; Graham, J. R.; Clampin, M.

    2008-01-01

    Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M(sub pl) < 3M(sub J), an orbital semimajor axis a(sub pl) > 101.5AU, and an orbital eccentricity e(sub pl) = 0.11 - 0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a approximately equals 133AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e approximately equals 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of approximately 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to approximately 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties are difficult to quantify. Even if the apsidal misalignment proves real, our calculated upper mass limit of 3 M(sub J) still holds. Parent bodies are evacuated from mean-motion resonances with Fom b; these empty resonances are akin to the Kirkwood gaps opened by Jupiter. The belt contains at least 3M(sub Earth) of solids that are grinding down to dust, their velocity dispersions stirred so strongly by Fom b that collisions are destructive. Such a large mass in solids is consistent with Fom b having formed in situ.

  8. From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets

    E-print Network

    Perez-Becker, Daniel Alonso

    2013-01-01

    M ? in the first place. A planet orbiting just inside theplanets having sizes up to about that of Mercury orbitingplanet in the Kepler database, then the occurrence rate of close-in progenitors orbiting

  9. A new Neptune-mass planet orbiting HD 219828

    E-print Network

    C. Melo; N. C. Santos; W. Gieren; G. Pietrzynski; M. T. Ruiz; S. G. Sousa; F. Bouchy; C. Lovis; M. Mayor; F. Pepe; D. Queloz; R. da Silva; S. Udry

    2007-02-20

    Two years ago a new benchmark for the planetary survey was set with the discoveries of three extrasolar planets with masses below 20$M_\\oplus$. In particular, the serendipitous discovery of the 14$M_\\oplus$ planet around $\\mu$ Ara found with HARPS with a semi-amplitude of only 4 m s$^{-1}$ put in evidence the tremendous potential of HARPS for the search of this class of very low-mass planets. Aiming to discovering new worlds similar to $\\mu$ Ara b, we carried out an intensive campaign with HARPS to observe a selected sample of northern stars covering a range of metallicity from about solar to twice solar. Two stars in our program were found to present radial velocity variations compatible with the presence of a planet-mass companion. The first of these, HD 219218, was found to be orbited by a planet with a minimum mass of 19.8 $M_\\oplus$ and an orbital period of 3.83 days. It is the 11th Neptune-mass planet found so far orbiting a solar-type star. The radial velocity data clearly show the presence of an additional body to the system, likely of planetary mass. The second planet orbits HD 102195, has a mass of 0.45$M_{Jup}$ and an orbital period of 4.11 days. This planet has been already announced by Ge et al. (2006). Our data confirm and improve the orbital solution found by these authors. We also show that the high residuals of the orbital solution are caused by stellar activity, and use the bisectors of the HARPS cross-correlation function to correct the noise introduced by stellar activity. An improved orbital solution is obtained after this correction. This kind of analysis may be used in the future to correct the radial-velocities for stellar activity induced noise.

  10. The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Cumming, Andrew; Butler, R. Paul; Marcy, Geoffrey W.; Vogt, Steven S.; Wright, Jason T.; Fischer, Debra A.

    2008-05-01

    We analyze 8 years of precise radial velocity measurements from the Keck Planet Search, characterizing the detection threshold, selection effects, and completeness of the survey. We first carry out a systematic search for planets, by assessing the false-alarm probability associated with Keplerian orbit fits to the data. This allows us to understand the detection threshold for each star in terms of the number and time baseline of the observations, and the underlying "noise" from measurement errors, intrinsic stellar jitter, or additional low-mass planets. We show that all planets with orbital periods P < 2000 days, velocity amplitudes K > 20 m s-1, and eccentricities e ? 0.6 have been announced, and we summarize the candidates at lower amplitudes and longer orbital periods. For the remaining stars, we calculate upper limits on the velocity amplitude of a companion. For orbital periods less than the duration of the observations, these are typically 10 m s-1 and increase ? P2 for longer periods. We then use the nondetections to derive completeness corrections at low amplitudes and long orbital periods and discuss the resulting distribution of minimum mass and orbital period. We give the fraction of stars with a planet as a function of minimum mass and orbital period and extrapolate to long-period orbits and low planet masses. A power-law fit for planet masses >0.3 MJ and periods < 2000 days gives a mass-period distribution dN = CM?P?d ln Md ln P with ? = -0.31 ± 0.2, ? = 0.26 ± 0.1, and the normalization constant C such that 10.5% of solar type stars have a planet with mass in the range 0.3--10 MJ and orbital period 2--2000 days. The orbital period distribution shows an increase in the planet fraction by a factor of ?5 for orbital periods ? 300 days. Extrapolation gives 17%--20% of stars having gas giant planets within 20 AU. Finally, we constrain the occurrence rate of planets orbiting M dwarfs compared to FGK dwarfs, taking into account differences in detectability.

  11. EXTRACTING PLANET MASS AND ECCENTRICITY FROM TTV DATA

    SciTech Connect

    Lithwick, Yoram; Xie Jiwei; Wu Yanqin

    2012-12-20

    Most planet pairs in the Kepler data that have measured transit time variations (TTVs) are near first-order mean-motion resonances. We derive analytical formulae for their TTV signals. We separate planet eccentricity into free and forced parts, where the forced part is purely due to the planets' proximity to resonance. This separation yields simple analytical formulae. The phase of the TTV depends sensitively on the presence of free eccentricity: if the free eccentricity vanishes, the TTV will be in phase with the longitude of conjunctions. This effect is easily detectable in current TTV data. The amplitude of the TTV depends on planet mass and free eccentricity, and it determines planet mass uniquely only when the free eccentricity is sufficiently small. We analyze the TTV signals of six short-period Kepler pairs. We find that three of these pairs (Kepler 18, 24, 25) have a TTV phase consistent with zero. The other three (Kepler 23, 28, 32) have small TTV phases, but ones that are distinctly non-zero. We deduce that the free eccentricities of the planets are small, {approx}< 0.01, but not always vanishing. Furthermore, as a consequence of this, we deduce that the true masses of the planets are fairly accurately determined by the TTV amplitudes, within a factor of {approx}< 2. The smallness of the free eccentricities suggests that the planets have experienced substantial dissipation. This is consistent with the hypothesis that the observed pile-up of Kepler pairs near mean-motion resonances is caused by resonant repulsion. But the fact that some of the planets have non-vanishing free eccentricity suggests that after resonant repulsion occurred there was a subsequent phase in the planets' evolution when their eccentricities were modestly excited, perhaps by interplanetary interactions.

  12. A Dynamical Method for Measuring Masses of Stars with Transiting Planets

    E-print Network

    Loeb, A

    2005-01-01

    As a planet transits the face of a star, it accelerates along the line-of-sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent transverse deceleration breaks the time-reversal symmetry in the transit lightcurve of a spherical planet in a circular orbit around a perfectly symmetric star. For `hot Jupiter' systems, ingress advances at a higher rate than egress by a fraction of 10^{-4}-10^{-3}. Forthcoming space telescopes such as Kepler or COROT will reach the sensitivity required to detect this asymmetry. The scaling of the fractional asymmetry with stellar mass M and planetary orbital radius R as M/R^2 is different from the scaling of the orbital period as (M/R^3)^{-1/2}. Therefore, this effect constitutes a new method for a purely dynamical determination of the mass of the star, which is currently inferred indirectly with theoretical uncertainties based on spectral modeling. Radial velocity data for the ...

  13. The Unusual Disintegrating Planet Candidate KIC 125557548b and Hot Jupiter CoRoT-1b in Transmission

    NASA Astrophysics Data System (ADS)

    Schlawin, Everett; Zhao, Ming; Teske, Johanna K.; Herter, Terry L.

    2015-01-01

    Transiting exoplanets are amenable to characterization because they absorb and scatter light from their host star when interrupting our line of sight. The wavelength dependence of the transit constrains the composition of the atmosphere. This in turn can be used to understand a planet's temperature profile and the possible launching mechanisms for evaporating atmospheres. To enable high precision transmission spectrum measurements, we acquire a target star and simultaneous reference star in the low-resolution mode of the SpeX spectrograph on the ground-based Infrared Telescope Facility (IRTF). This observational setup has achieved transit depth precision of 900 ppm and below for faint (K > 12) systems, allowing for characterization of interesting exoplanets discovered by the CoRoT and Kepler spacecraft. We test the TiO/VO hypothesis on a hot Jupiter CoRoT-1b (that TiO and VO create a temperature inversion) and characterize the debris escaping from the disintegrating rocky planet candidate KIC 12557548b.

  14. Newton's determination of the masses and densities of the Sun, Jupiter, Saturn and the Earth.

    NASA Astrophysics Data System (ADS)

    Cohen, I. B.

    1998-05-01

    This article analyzes the methods Newton applied in his Principia for calculating the masses and densities of the Sun and planets, and in particular, investigates the origins of the numerical parameter values used by Newton in these calculations.

  15. The Influence of Giant Planet Mass on Long-Period Comet Flux

    NASA Astrophysics Data System (ADS)

    Lewis, Alexia; Quinn, T.

    2012-01-01

    We study the effect of the outer solar system architecture on the flux of Earth-crossing comets. In particular, we seek to quantify the role of the giant planets as ``planetary protectors''. Because the outer planets modify the structure of the Oort Cloud throughout its formation, we must follow its evolution over the full age of the solar system. We have run simulations in each of 4 different planetary mass configurations to analyze the structure and formation of each Oort Cloud and to better constrain the flux of comets into the inner solar system. Particles are integrated over 4.5 Gyrs under the influence of the giant planets, the Galactic tide, and passing stars. We find that the structure of the Oort Cloud, including the location of boundaries and the relative number of comets in the inner and outer Oort Cloud, does not change significantly between configurations. As overall planetary mass decreases, the flux of comets increases. Trapping efficiency of the Oort Cloud also increases, as expected. We find that Saturn is as effective as Jupiter at deflecting possible Earth-crossing comets, as reflected by the fact that a comparable numbers of particles enter the inner solar system when we independently reduce their masses. In each configuration, we confirm the conclusion from Kaib & Quinn (2009) that the majority of observable comets originate in the inner Oort Cloud. Although the final effect may be small, accounting for the formation and growth of the giant planets in simulations may help us better understand the trapping efficiency of the Oort Cloud and the mass of the protoplanetary disk.

  16. Determination of the minimum masses of heavy elements in the envelopes of Jupiter and Saturn

    E-print Network

    Olivier Mousis; Ulysse Marboeuf; Jonathan I. Lunine; Yann Alibert; Leigh N. Fletcher; Glenn S. Orton; Francoise Pauzat; Yves Ellinger

    2008-12-12

    We calculate the minimum mass of heavy elements required in the envelopes of Jupiter and Saturn to match the observed oversolar abundances of volatiles. Because the clathration efficiency remains unknown in the solar nebula, we have considered a set of sequences of ice formation in which the fraction of water available for clathration is varied between 0 and 100 %. In all the cases considered, we assume that the water abundance remains homogeneous whatever the heliocentric distance in the nebula and directly derives from a gas phase of solar composition. Planetesimals then form in the feeding zones of Jupiter and Saturn from the agglomeration of clathrates and pure condensates in proportions fixed by the clathration efficiency. A fraction of Kr and Xe may have been sequestrated by the H3+ ion in the form of stable XeH3+ and KrH3+ complexes in the solar nebula gas phase, thus implying the formation of at least partly Xe- and Kr-impoverished planetesimals in the feeding zones of Jupiter and Saturn. These planetesimals were subsequently accreted and vaporized into the hydrogen envelopes of Jupiter and Saturn, thus engendering volatiles enrichments in their atmospheres, with respect to hydrogen. Taking into account both refractory and volatile components, and assuming plausible molecular mixing ratios in the gas phase of the outer solar nebula, we show that it is possible to match the observed enrichments in Jupiter and Saturn, whatever the clathration efficiency. Our calculations predict that the O/H enrichment decreases from 6.7 to 5.6 times solar (O/H) in the envelope of Jupiter and from 18.1 to 15.4 times solar (O/H) in the envelope of Saturn with the growing clathration efficiency in the solar nebula.

  17. AB INITIO EQUATION OF STATE FOR HYDROGEN-HELIUM MIXTURES WITH RECALIBRATION OF THE GIANT-PLANET MASS-RADIUS RELATION

    SciTech Connect

    Militzer, B.; Hubbard, W. B.

    2013-09-10

    Using density functional molecular dynamics simulations, we determine the equation of state (EOS) for hydrogen-helium mixtures spanning density-temperature conditions typical of giant-planet interiors, {approx}0.2-9 g cm{sup -3} and 1000-80,000 K for a typical helium mass fraction of 0.245. In addition to computing internal energy and pressure, we determine the entropy using an ab initio thermodynamic integration technique. A comprehensive EOS table with 391 density-temperature points is constructed and the results are presented in the form of a two-dimensional free energy fit for interpolation. Deviations between our ab initio EOS and the semi-analytical EOS model by Saumon and Chabrier are analyzed in detail, and we use the results for initial revision of the inferred thermal state of giant planets with known values for mass and radius. Changes are most pronounced for planets in the Jupiter mass range and below. We present a revision to the mass-radius relationship that makes the hottest exoplanets increase in radius by {approx}0.2 Jupiter radii at fixed entropy and for masses greater than {approx}0.5 Jupiter mass. This change is large enough to have possible implications for some discrepant ''inflated giant exoplanets''.

  18. MASSES, RADII, AND CLOUD PROPERTIES OF THE HR 8799 PLANETS

    SciTech Connect

    Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard E-mail: dsaumon@lanl.gov E-mail: andrew.ackerman@nasa.gov E-mail: freedman@darkstar.arc.nasa.gov

    2012-08-01

    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Some studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here, we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against observations of field L and T dwarfs, including the reddest L dwarfs. Unlike some previous studies, we require mutually consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure thus yields plausible values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are not unusual but rather follow previously recognized trends, including a gravity dependence on the temperature of the L to T spectral transition-some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to whether or not we include the H- and the K-band spectrum in our analysis. Solutions for planets c and d are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that, like in L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present an exploratory evolution calculation that accounts for this effect. Finally we recompute the bolometric luminosity of all three planets.

  19. Terrestrial Planet Formation around Low-Mass Stars: Effect of the Mass of Central Stars

    NASA Astrophysics Data System (ADS)

    Oshino, Shoichi; Matsumoto, Yuji; Kokubo, Eiichiro

    2015-12-01

    The Kepler space telescope has detected several thousand planets and candidates.Their central stars are mainly FGK-type stars.It is difficult to observe M-stars by using visible light since M-stars have their peak radiation in the infrared region.However, recently there are several survey projects for planets around M-stars such as the InfraRed Doppler (IRD) survey of the Subaru telescope.Therefore it is expected that the number of planets around M-stars will increase in the near future.The habitable zone of M-stars is closer to the stars than that of G-stars.For this reason, the possibility of finding habitable planets is expected to be higher.Here we study the formation of close-in terrestrial planets by giant impacts of protoplanets around low-mass stars by using N-body simulations.An important parameter that controls formation processes is the ratio between the physical radius of a planet and its Hill radius, which decreases with the stellar mass.We systematically change the mass of the central stars and investigate its effects on terrestrial planet formation.We find that the mass of the maximum planet decreases with the mass of central stars, while the number of planets in the system increases.We also find that the orbital separation of adjacent planets normalized by their Hill radius increases with the stellar mass.

  20. Masses of the Five Small Planets Around Kepler-80

    NASA Astrophysics Data System (ADS)

    MacDonald, Mariah G.; Ragozzine, Darin; Fabrycky, Daniel C.

    2015-11-01

    Kepler has discovered hundreds of multi-transiting systems which hold tremendous potential both individually and collectively for understanding the formation and evolution of planetary systems. Many of these systems are quite compact, containing 3-7 relatively small planets with periods less than 100 days; these are known as Systems with Tightly-packed Inner planets, or STIPs. One ultra-compact STIP is KOI-500/Kepler-80, a planetary system containing five transiting planets ranging in size from 1.5 to 2.8 times the radius of the Earth that orbit in a tightly-packed configuration with periods between 1 and 10 days. In addition to its close packedness, the outer four planets are in a unique dynamical configuration with two interconnected three-body resonances. Using transit timing variations (TTVs) caused by the gravitational perturbations, we perform a fully self-consistent dynamical analysis of the system, finding best-fit masses for the outer four planets to be each around five Earth masses. We also performed extensive testing of synthetic systems, and have determined that eccentricities cannot be reliably detected, but that assuming circular orbits does not significantly affect the mass estimates. We will present the inferred properties for Kepler-80 and discuss these results in context of (ultra-compact) STIPs and the small planet mass-radius relation.

  1. THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

    E-print Network

    Guo, Jianheng

    By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass ...

  2. Methane planets and the mass-radius diagram

    NASA Astrophysics Data System (ADS)

    Podolak, Morris; Helled, Ravit; Levi, Amit

    2014-05-01

    The multitude of newly discovered exoplanets are too far away to be studied in the same detail as the planets of our own solar system. Many planets have measured masses and radii, and their mean densities can be compared to those expected for different simple compositions (see, e.g. Seager et al. 2007). Clearly, different mixtures of materials can give similar density distributions and as a result, the mass and radius of a planet do not give a unique composition. It turns out that even if we limit the composition to one species, the mass-radius relation can show complex structure. To illustrate this, we consider planets composed of pure CH4. The complications arise because CH4 is expected to undergo dissociation at high pressure. Ab initio calculations (Gao et al. 2010) suggest that CH4 dissociates to C2H6, C4H10, and finally carbon + hydrogen at progressively higher pressures. We have modeled isothermal planets composed initially of pure CH4. We assume that if the planet is massive enough so that the central pressure exceeds the dissociation pressure of CH4, a diamond core is formed and the hydrogen released diffuses through the intermediate CH4 shell to form an H2 atmosphere. This leads to a sharp discontinuity in the mass-radius relation for such planets. A further complication arises from the fact that within a narrow range around the transition mass there can be multiple solutions ranging from a pure CH4 planet to those with diamond cores, CH4 shells, and hydrogen atmospheres of different masses. Methane planets thus provide an example of the instability first noted by Ramsey (1950) and Lighthill (1950). As a result, even for a given composition the mass-radius diagram is non-unique, making the characterization of extrasolar planets even more challenging. REFERENCES Gao, G., Oganov, A. R., Wang, H., Li, P., Ma, Y., Cui, T., and Zou, G., 2010. Dissociation of methane under high pressure. J. Chem. Phys., 133:144,508-1 - 144,508-5. Lighthill, M. J., 1950. On the instability of small planetary cores (II). Mon. Not. RAS, 110:339. Ramsey, W. H., 1950. On the instability of small planetary cores (I). Mon. Not. RAS, 110:325. Seager, S., Kuchner, M., Hier-Majumder, C. A., and Militzer, B., 2007. Mass-radius relationships for solid exoplanets. Astrophys. J., 669:1279-1297.

  3. A rocky planet transiting a nearby low-mass star

    NASA Astrophysics Data System (ADS)

    Berta-Thompson, Zachory K.; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R.; Dittmann, Jason; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michael; Jehin, Emmanuel; Stark, Antony; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christoph; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno; Udry, Stéphane; Wunsche, Anael

    2015-12-01

    Results from Kepler indicate that M dwarfs host, on average, at least 1.4 planets between 0.5 and 1.5 Earth radii per star. Yet, the closest small planets known to transit M dwarfs have been too distant to allow Doppler measurements of their masses or spectroscopic studies of their atmospheres. Here, we announce a new planet discovered by the MEarth-South observatory, an Earth-size planet transiting an M dwarf that is only 12 pc away. The density of the planet, determined from radial velocity observations with HARPS, is consistent with an Earth-like rock/iron composition. With an equilibrium temperature of 530K (assuming a Bond albedo of 0.3), this planet is cooler than most other rocky planets with measured densities. Although too hot to be habitable, it is cool enough that it may have retained a substantial atmosphere over its lifetime. Thanks to the star's proximity and its diminutive size of only 1/5th the radius of the Sun, this new world likely provides the first opportunity for our community to spectroscopically examine the atmosphere of a terrestrial exoplanet. We estimate that JWST could secure high signal-to-noise spectra of the planet's atmosphere, both in transmission during transit and in emission at secondary eclipse.

  4. An Earth-mass planet orbiting ? Centauri B.

    PubMed

    Dumusque, Xavier; Pepe, Francesco; Lovis, Christophe; Ségransan, Damien; Sahlmann, Johannes; Benz, Willy; Bouchy, François; Mayor, Michel; Queloz, Didier; Santos, Nuno; Udry, Stéphane

    2012-11-01

    Exoplanets down to the size of Earth have been found, but not in the habitable zone--that is, at a distance from the parent star at which water, if present, would be liquid. There are planets in the habitable zone of stars cooler than our Sun, but for reasons such as tidal locking and strong stellar activity, they are unlikely to harbour water-carbon life as we know it. The detection of a habitable Earth-mass planet orbiting a star similar to our Sun is extremely difficult, because such a signal is overwhelmed by stellar perturbations. Here we report the detection of an Earth-mass planet orbiting our neighbour star ? Centauri B, a member of the closest stellar system to the Sun. The planet has an orbital period of 3.236 days and is about 0.04 astronomical units from the star (one astronomical unit is the Earth-Sun distance). PMID:23075844

  5. LETTER doi:10.1038/nature10076 Hot Jupiters from secular planetplanet interactions

    E-print Network

    Rasio, Frederic A.

    Jupiters' (extrasolar Jovian-mass planets with close-in orbits) are actually orbiting counter to the spin evolution of the inner orbit allows planet­star tidal interactions to rapidly circularize that orbit to the protoplanetary disk12,13 . This `migration' process should produce planets with low orbital inclinations

  6. The Planets Around Low-Mass Stars (PALMS) Direct Imaging Survey

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.; Liu, M. C.; Shkolnik, E.; Mann, A.; Tamura, M.

    2013-01-01

    Direct imaging is the only method to study the outer architecture (>10 AU) of extrasolar planetary systems in a targeted fashion. Previous imaging surveys have primarily focused on intermediate- and high-mass stars because of the relative dearth of known nearby young M dwarfs. As a result, even though M dwarfs make up 70% of stars in our galaxy, there are few constraints on the population of giant planets at moderate separations (10-100 AU) in this stellar mass regime. We present results from an ongoing high-contrast adaptive optics imaging survey targeting newly identified nearby (<35 pc) young (<300 Myr) M dwarfs with Keck-2/NIRC2 and Subaru/HiCIAO. We have already discovered four young brown dwarf companions with masses between 30-70 Mjup; two of these are members of the ~120 Myr AB Dor moving group, and another one will yield a dynamical mass in the near future. Follow-up optical and near-infrared spectroscopy of these companions reveal spectral types of late-M to early-L and spectroscopic indicators of youth such as angular H-band morphologies, weak J-band alkali lines, and Li absorption and Halpha emission in one target. Altogether our survey is sensitive to planet masses a few times that of Jupiter at separations down to ~10 AU. With a sample size of roughly 80 single M dwarfs, this program represents the deepest and most extensive imaging search for planets around young low-mass stars to date.

  7. Architectural Insights into the Origin of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Schlaufman, Kevin C.; Winn, Joshua

    2015-12-01

    The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. This problem has been with us for 20 years, long enough for significant progress to have been made, and also for a great deal of "lore" to have accumulated about the properties of these planets. Among this lore is the widespread belief that hot Jupiters are less likely be in multiple giant planet systems than longer-period giant planets. We will show that in this case the lore is not supported by the best data available today: hot Jupiters are no more or less likely than warm or cool Jupiters to have additional Jupiter-mass companions. In contrast to the expectation from the simplest models of high-eccentricity migration, the result holds for Jupiter-mass companions both inside and outside of the water-ice line. This support the importance of disk migration for the origin of short-period giant planets.

  8. Probing Clouds in Planets with a Simple Radiative Transfer Model: The Jupiter Case

    ERIC Educational Resources Information Center

    Mendikoa, Inigo; Perez-Hoyos, Santiago; Sanchez-Lavega, Agustin

    2012-01-01

    Remote sensing of planets evokes using expensive on-orbit satellites and gathering complex data from space. However, the basic properties of clouds in planetary atmospheres can be successfully estimated with small telescopes even from an urban environment using currently available and affordable technology. This makes the process accessible for…

  9. Jupiter’s decisive role in the inner Solar System’s early evolution

    PubMed Central

    Batygin, Konstantin; Laughlin, Greg

    2015-01-01

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ? 1.5 AU before reversing direction, can explain the low overall mass of the Solar System’s terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter’s inward migration entrained s ? 10?100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System’s terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution. PMID:25831540

  10. An extrasolar planetary system with three Neptune-mass planets

    E-print Network

    C. Lovis; M. Mayor; F. Pepe; Y. Alibert; W. Benz; F. Bouchy; A. C. M. Correia; J. Laskar; C. Mordasini; D. Queloz; N. C. Santos; S. Udry; J. -L. Bertaux; J. -P. Sivan

    2007-03-01

    Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 AU (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

  11. An extrasolar planetary system with three Neptune-mass planets.

    PubMed

    Lovis, Christophe; Mayor, Michel; Pepe, Francesco; Alibert, Yann; Benz, Willy; Bouchy, François; Correia, Alexandre C M; Laskar, Jacques; Mordasini, Christoph; Queloz, Didier; Santos, Nuno C; Udry, Stéphane; Bertaux, Jean-Loup; Sivan, Jean-Pierre

    2006-05-18

    Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star. PMID:16710412

  12. The Use of Transit Timing to Detect Extrasolar Planets with Masses as Small as Earth

    E-print Network

    Matthew J. Holman; Norman W. Murray

    2004-12-01

    Future surveys for transiting extrasolar planets, including the space-based mission Kepler (Borucki et al 2003), are expected to detect hundreds of Jovian mass planets and tens of terrestrial mass planets. For many of these newly discovered planets, the intervals between successive transits will be measured with an accuracy of 0.1--100 minutes. We show that these timing measurements will allow for the detection of additional planets in the system (not necessarily transiting), via their gravitational interaction with the transiting planet. The transit time variations depend on the mass of the additional planet, and in some cases Earth-mass planets will produce a measurable effect.

  13. Hydrogen Eos at Megabar Pressures and the Search for Jupiter's Core

    NASA Astrophysics Data System (ADS)

    Hubbard, William B.

    2005-07-01

    The interior structure of Jupiter serves as a benchmark for an entire astrophysical class of liquid metallic hydrogen-rich objects with masses ranging from ~0.1M J to ~80M J (1M J = Jupiter mass = 1.9e30 g), comprising hydrogen-rich giant planets (mass < 13M J) and brown dwarfs (mass > 13M J but ~ < 80M J), the so-called substellar objects (SSOs). Formation of giant planets may involve nucleated collapse of nebular gas onto a solid, dense core of mass ~0.04M J rather than a stellar-like gravitational instability. Thus, detection of a primordial core in Jupiter is a prime objective for understanding the mode of origin of extrasolar giant planets and other SSOs. A basic method for core detection makes use of direct modeling of Jupiter’s external gravitational potential terms in response to rotational and tidal perturbations, and is highly sensitive to the thermodynamics of hydrogen at multi-megabar pressures. The present-day core masses of Jupiter and Saturn may be larger than their primordial core masses due to sedimentation of elements heavier than hydrogen. We show that there is a significant contribution of such sedimented mass to Saturn’s core mass. The sedimentation contribution to Jupiter’s core mass will be smaller and could be zero.

  14. The Structural and Thermal Evolution of Transiting Exoplanets: From Hot Jupiters to Kepler's Super Earths

    SciTech Connect

    Fortney, Jonathan

    2011-06-11

    Large numbers of exoplanets can now be seen to transit their parent stars, which allows for measurements of their radii, masses, and densities. We can now begin to examine the Jupiter-class gas giant planets as a class of astrophysical objects. At the same time, thanks to NASA’s Kepler telescope, the number of transiting planets below 10 Earth masses is now moving beyond just a handful. For the Jupiter-like planets, we model their interior structure and find several interesting properties regarding the amount of ice and rock within these planets, which gives us clues to their formation. For the lowest-mass planets, such as the 6-planet Kepler-11 system, signs point to a large populations of mini-Neptunes---low-mass, low-density planets with hydrogen-dominated atmospheres. The Kepler-11 system may tell us much about the evaporation of the atmospheres of these kinds of planets.

  15. Meteoritical and dynamical constraints on the growth mechanisms and formation times of asteroids and Jupiter

    E-print Network

    Edward R. D. Scott

    2006-07-13

    Peak temperatures inside meteorite parent bodies are closely linked to accretion times. Most iron meteorites come from bodies that accreted Jupiter. Therefore Jupiter probably reached its current mass >3-5 Myr after CAIs formed. This precludes formation of Jupiter via a gravitational instability Jupiter, or by planetary embryos may have produced some chondrules. The minimum lifetime for the solar nebula of 3-5 Myr inferred from CAI and chondrule ages may exceed the median 3 Myr lifetime for protoplanetary disks, but is well within the total 1-10 Myr range. Shorter formation times for extrasolar planets may help to explain why their orbits are unlike those of solar giant planets.

  16. Accretion of the gaseous envelope of Jupiter around a 5 10 Earth-mass core

    NASA Astrophysics Data System (ADS)

    Hubickyj, Olenka; Bodenheimer, Peter; Lissauer, Jack J.

    2005-12-01

    New numerical simulations of the formation and evolution of Jupiter are presented. The formation model assumes that first a solid core of several M accretes from the planetesimals in the protoplanetary disk, and then the core captures a massive gaseous envelope from the protoplanetary disk. Earlier studies of the core accretion-gas capture model [Pollack, J.B., Hubickyj, O., Bodenheimer, P., Lissauer, J.J., Podolak, M., Greenzweig, Y., 1996. Icarus 124, 62-85] demonstrated that it was possible for Jupiter to accrete with a solid core of 10-30 M in a total formation time comparable to the observed lifetime of protoplanetary disks. Recent interior models of Jupiter and Saturn that agree with all observational constraints suggest that Jupiter's core mass is 0-11 M and Saturn's is 9-22 M [Saumon, G., Guillot, T., 2004. Astrophys. J. 609, 1170-1180]. We have computed simulations of the growth of Jupiter using various values for the opacity produced by grains in the protoplanet's atmosphere and for the initial planetesimal surface density, ?, in the protoplanetary disk. We also explore the implications of halting the solid accretion at selected core mass values during the protoplanet's growth. Halting planetesimal accretion at low core mass simulates the presence of a competing embryo, and decreasing the atmospheric opacity due to grains emulates the settling and coagulation of grains within the protoplanet's atmosphere. We examine the effects of adjusting these parameters to determine whether or not gas runaway can occur for small mass cores on a reasonable timescale. We compute four series of simulations with the latest version of our code, which contains updated equation of state and opacity tables as well as other improvements. Each series consists of a run without a cutoff in planetesimal accretion, plus up to three runs with a cutoff at a particular core mass. The first series of runs is computed with an atmospheric opacity due to grains (hereafter referred to as 'grain opacity') that is 2% of the interstellar value and ?=10g/cm. Cutoff runs are computed for core masses of 10, 5, and 3 M. The second series of Jupiter models is computed with the grain opacity at the full interstellar value and ?=10g/cm. Cutoff runs are computed for core masses of 10 and 5 M. The third series of runs is computed with the grain opacity at 2% of the interstellar value and ?=6g/cm. One cutoff run is computed with a core mass of 5 M. The final series consists of one run, without a cutoff, which is computed with a temperature dependent grain opacity (i.e., 2% of the interstellar value for T<350K ramping up to the full interstellar value for T>500K) and ?=10g/cm. Our results demonstrate that reducing grain opacities results in formation times less than half of those for models computed with full interstellar grain opacity values. The reduction of opacity due to grains in the upper portion of the envelope with T?500K has the largest effect on the lowering of the formation time. If the accretion of planetesimals is not cut off prior to the accretion of gas, then decreasing the surface density of planetesimals lowers the final core mass of the protoplanet, but increases the formation timescale considerably. Finally, a core mass cutoff results in a reduction of the time needed for a protoplanet to evolve to the stage of runaway gas accretion, provided the cutoff mass is sufficiently large. The overall results indicate that, with reasonable parameters, it is possible that Jupiter formed at 5 AU via the core accretion process in 1 Myr with a core of 10 M or in 5 Myr with a core of 5 M.

  17. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS

    SciTech Connect

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2009-07-10

    We study the final architecture of planetary systems that evolve under the combined effects of planet-planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet-planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For M {sub tot} {approx}> 1 M{sub J} the final eccentricity distribution remains broad, whereas for M {sub tot} {approx}< 1 M{sub J} a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a {approx_equal} 5-10 AU.

  18. Formation of giant planets around stars with various masses

    NASA Astrophysics Data System (ADS)

    Kornet, K.; Wolf, S.; Ró?yczka, M.

    2006-11-01

    We examine the predictions of the core accretion - gas capture model concerning the efficiency of planet formation around stars with various masses. First, we follow the evolution of gas and solids from the moment when all solids are in the form of small grains to the stage when most of them are in the form of planetesimals. We show that the surface density of the planetesimal swarm tends to be higher around less massive stars. Then, we derive the minimum surface density of the planetesimal swarm required for the formation of a giant planet both in a numerical and in an approximate analytical approach. We combine these results by calculating a set of representative disk models characterized by different masses, sizes, and metallicities, and by estimating their capability of forming giant planets. Our results show that the set of protoplanetary disks capable of giant planet formation is larger for less massive stars. Provided that the distribution of initial disk parameters does not depend too strongly on the mass of the central star, we predict that the percentage of stars with giant planets should increase with decreasing stellar mass. Furthermore, we identify the radial redistribution of solids during the formation of planetesimal swarms as the key element in explaining these effects.

  19. Tracking the Planet-Planet Interactions by Statistics: The Period-Ratio and Mass-Ratio Correlation

    NASA Astrophysics Data System (ADS)

    Jiang, Ing-Guey; Yeh, Li-Chin

    2015-08-01

    Employing the data from orbital periods and masses of extra-solar planets in 166 multiple planetary systems, the period-ratio and mass-ratio of adjacent planet pairs are studied.The correlation between the period-ratio and mass-ratio is confirmed and found to have a correlation coefficientof 0.5303 with a 99% confidence interval (0.3807, 0.6528).A comparison with the distribution of synthetic samples from a Monte Carlo simulation reveals the imprint of planet-planet interactions on the formation of adjacent planet pairs in multiple planetary systems.

  20. KMT-2015-1b: a Giant Planet Orbiting a Low-mass Dwarf Host Star Discovered by a New High-cadence Microlensing Survey with a Global Telescope Network

    E-print Network

    Hwang, K -H; Choi, J -Y; Park, H; Jung, Y K; Shin, I -G; Albrow, M D; Gould, A; Bozza, V; Park, B -G; Kim, S -L; Lee, C -U; Cha, S -M; Kim, D -J; Lee, Y

    2015-01-01

    We report the discovery of an extrasolar planet, KMT-2015-1b, that was detected using the microlensing technique. The planetary lensing event was observed by KMTNet survey that has commenced in 2015. With dense coverage by using network of globally distributed telescopes equipped with very wide-field cameras, the short planetary signal is clearly detected and precisely characterized. We find that KMT-2015-1b is a giant planet orbiting a low-mass M-dwarf host star. The planet has a mass about twice that of Jupiter and it is located beyond the snow line of the host star. With the improvement of existing surveys and the advent of new surveys, future microlensing planet samples will include planets not only in greatly increased number but also in a wide spectrum of hosts and planets, helping us to have a better and comprehensive understanding about the formation and evolution of planets.

  1. Qatar-2: A K Dwarf Orbited by a Transiting Hot Jupiter and a Longer-Period Massive Planet

    NASA Astrophysics Data System (ADS)

    Bryan, Marta; Alsubai, K. A.; Latham, D. W.; Quinn, S. N.; Collier Cameron, A.; Carter, J. A.; Buchave, L. A.

    2012-01-01

    We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a K dwarf in a circular orbit with a short period, Pb = 1.34 days. Differential photometry and model fitting of transit data from both KeplerCam and LCOGT yielded light curve parameters Rp/Rs, a/Rs, u1, u2, and i that were optimized using the Markov Chain Monte Carlo technique. Radial velocity measurements from the Tillinghast Reflector Echelle Spectrograph of Qatar-2 over a span of 153 days provided a mass estimate for Qatar-2b, with velocity residuals from the orbital solution that pointed to the presence of a third body in the system. The light curve parameter a/Rs and spectroscopic values for effective temperature and metallicity were used in conjunction with stellar models to estimate the mass and radius of Qatar-2, leading to a mass and radius for Qatar-2b of MP = 2.54 MJ and RP = 1.14 RJ, respectively. Next we used the Systemic Console to explore possible orbital solutions for the outer companion, Qatar-2c. Plausible solutions have periods slightly less than a year and a mass of several MJ. However, further observations are needed to determine a reliable orbit for Qatar-2c. Qatar-2 is only the fourth example in the short but growing list of systems with a transiting hot Jupiter and an outer companion. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar.

  2. Fast migration of low-mass planets in radiative discs

    NASA Astrophysics Data System (ADS)

    Pierens, A.

    2015-12-01

    Low-mass planets are known to undergo Type I migration and this process must have played a key role during the evolution of planetary systems. Analytical formulae for the disc torque have been derived assuming that the planet evolves on a fixed circular orbit. However, recent work has shown that in isothermal discs, a migrating protoplanet may also experience dynamical corotation torques that scale with the planet drift rate. The aim of this study is to examine whether dynamical corotation torques can also affect the migration of low-mass planets in non-isothermal discs. We performed 2D radiative hydrodynamical simulations to examine the orbital evolution outcome of migrating protoplanets as a function of disc mass. We find that a protoplanet can enter a fast migration regime when it migrates in the direction set by the entropy-related horseshoe drag and when the Toomre stability parameter is less than a threshold value below which the horseshoe region contracts into a tadpole-like region. In that case, an underdense trapped region appears near the planet, with an entropy excess compared to the ambient disc. If the viscosity and thermal diffusivity are small enough so that the entropy excess is conserved during migration, the planet then experiences strong corotation torques arising from the material flowing across the planet orbit. During fast migration, we observe that a protoplanet can pass through the zero-torque line predicted by static torques. We also find that fast migration may help in disrupting the mean-motion resonances that are formed by convergent migration of embryos.

  3. Masses, Radii, and Cloud Properties of the HR 8799 Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard

    2012-01-01

    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have compared the photometric and limited spectral data of the planets to the predictions of various atmosphere and evolution models and concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Most studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against field L and T dwarfs, including the reddest L dwarfs. Unlike almost all previous studies we specify mutually self-consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure yields plausible and self-consistent values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are in fact not unusual but rather follow previously recognized trends including a gravity dependence on the temperature of the L to T spectral transition, some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to the H and K band spectrum. Solutions for planets c and particularly d are less certain but are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that as for L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present a new evolution calculation that predicts cooling tracks on the near-infrared color-magnitude diagram. Finally we argue that the range of uncertainty conventionally quoted for the bolometric luminosity of all three planets is too small.

  4. Revised Masses and Densities of the Planets around Kepler-10

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Rogers, Leslie A.; Isaacson, Howard T.; Agol, Eric; Marcy, Geoffrey W.; Rowe, Jason F.; Kipping, David; Fulton, Benjamin; Lissauer, Jack; Howard, Andrew; Clark Fabrycky, Daniel

    2015-12-01

    Determining which small exoplanets have stony-iron compositions is necessary for quantifying the occurrence of such planets and for understanding the physics of planet formation. Kepler-10 hosts the stony-iron world Kepler-10b, and also contains what has been reported to be the largest solid silicate-ice planet, Kepler-10c. Using 220 radial velocities (RVs), including 72 new precise RVs from Keck-HIRES, and 17 quarters of Kepler photometry, we obtain the most complete picture of the Kepler-10 system to date. We find that Kepler-10b (Rp = 1.47 R?) has mass 3.70 ± 0.43 M? and density 6.44 ± 0.73 g cm?3. Modeling the interior of Kepler-10b as an iron core overlaid with a silicate mantle, we find that the core constitutes 0.17 ± 0.11 of the planet mass. For Kepler-10c (Rp = 2.35 R?) we measure mass 13.32 ± 1.65 M?and density 5.67 ± 0.70 g cm?3, significantly lower than the mass in Dumusque et al. (2014, 17.2±1.9 M?). Kepler-10c is not sufficiently dense to have a pure stony-iron composition. Internal compositional modeling reveals that at least 10% of the radius of Kepler-10c is a volatile envelope composed of either hydrogen-helium (0.0027 ± 0.0015 of the mass, 0.172±0.037 of the radius) or super-ionic water (0.309±0.11 of the mass, 0.305±0.075 of the radius). Transit timing variations (TTVs) of Kepler-10c indicate the likely presence of a third planet in the system, KOI-72.X. The TTVs and RVs are consistent with KOI-72.X having an orbital period of 24, 71, 82, or 101 days, and a mass from 1-7 M?.

  5. Formation of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    An overview of current theories of the formation of our Solar System, with emphasis on giant planets, is presented. The most detailed models are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Larger disk mass allows for faster growth of solid planetary bodies. The ability of a solid planet to trap gas from the protoplanetary disk increases rapidly as its mass increases (because the depth of its gravitational potential well increases), but decreases as the planetesimal accretion rate is increased (as it becomes hotter). The net effect of increasing disk mass is that gas giant planets form more rapidly, but with larger core masses. Observations of circumstellar disks suggest an upper bound on the time available prior to dissipation of the gas, and planetary models place upper limits on core sizes. Together, these constraints suggest that Jupiter and Saturn formed in 1 - 10 million years, and the density of solids in the region of their formation was a few times as large as the lower bound provided by the traditional minimum mass nebula.

  6. Formation of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of the formation of our Solar System, with emphasis on giant planets, is presented. The most detailed models are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Larger disk mass allows for faster growth of solid planetary bodies. The ability of a solid planet to trap gas from the protoplanetary disk increases rapidly as its mass increases (because the depth of its gravitational potential well increases), but decreases as the planetesimal accretion rate is increased (as it becomes hotter). The net effect of increasing disk mass is that gas giant planets form more rapidly, but with larger core masses. Observations of circumstellar disks suggest an upper bound on the time available prior to dissipation of the gas, and planetary models place upper limits on core sizes. Together, these constraints suggest that Jupiter and Saturn formed in 1-10 million years, and the density of solids in the region of their formation was a few times as large as the lower bound provided by the traditional minimum mass nebula.

  7. THE DEUTERIUM-BURNING MASS LIMIT FOR BROWN DWARFS AND GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Burrows, Adam; Milsom, John A. E-mail: burrows@astro.princeton.edu

    2011-01-20

    There is no universally acknowledged criterion to distinguish brown dwarfs from planets. Numerous studies have used or suggested a definition based on an object's mass, taking the {approx}13 Jupiter mass (M{sub J} ) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 M{sub J} is generally a reasonable rule of thumb, the deuterium fusion mass depends on the helium abundance, the initial deuterium abundance, the metallicity of the model, and on what fraction of an object's initial deuterium abundance must combust in order for the object to qualify as having burned deuterium. Even though, for most proto-brown dwarf conditions, 50% of the initial deuterium will burn if the object's mass is {approx}(13.0 {+-} 0.8) M{sub J} , the full range of possibilities is significantly broader. For models ranging from zero-metallicity to more than three times solar metallicity, the deuterium-burning mass ranges from {approx}11.0 M{sub J} (for three times solar metallicity, 10% of initial deuterium burned) to {approx}16.3 M{sub J} ( for zero metallicity, 90% of initial deuterium burned).

  8. The Deuterium-Burning Mass Limit for Brown Dwarfs and Giant Planets

    E-print Network

    Spiegel, David S; Milsom, John A

    2010-01-01

    There is no universally acknowledged criterion to distinguish brown dwarfs from planets. Numerous studies have used or suggested a definition based on an object's mass, taking the ~13-Jupiter mass (M_J) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 M_J is generally a reasonable rule of thumb, the deuterium fusion mass depends on the helium abundance, the initial deuterium abundance, the metallicity of the model, and on what fraction of an object's initial deuterium abundance must combust in order for the object to qualify as having burned deuterium. Even though, for most proto-brown dwarf conditions, 50% of the initial deuterium will burn if the object's mass is ~(13.0 +/- 0.8)M_J, the full range of possibilities is significantly broader. For models ranging from zero-metallicity to more than three times solar metallicity, the deuterium burning mass ranges from ~11.0 M_J (for 3-times solar metallicity, 10% of initial deu...

  9. Considerations on the Outward Migration of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    D'Angelo, G.; Marzari, F.

    2011-12-01

    It has been proposed that the outward orbital migration of Jupiter and Saturn, driven by a gas-dominated protosolar disk, may help explain why they did not move much closer to the Sun. It has also been suggested that some properties of the inner Solar System may be interpreted by invoking an inward migration of Jupiter and Saturn followed by outward migration, once they get caught in the 2:3 mean motion resonance. Hydrodynamical calculations indicate that outward migration of a compact Jupiter-Saturn system may arise from an imbalance between positive and negative Lindblad torques exerted on Jupiter by the disk. The torque density distribution acting on Jupiter extends over ~3 Hill radii on either side of the planet's orbit. The negative part of the distribution samples outer disk portions, partially depleted by the tidal perturbations of both planets. The positive part of the distribution samples inner disk portions, depleted only by the action of Jupiter. The net result may be a positive torque exerted on Jupiter. Saturn, trapped in resonance with Jupiter, migrates outward as well. This mechanism requires the exterior planet's mass not to exceed the interior planet's mass. Thus, it is assumed that neither planet accretes gas from the disk. Yet, models of giant planet formation indicate that these planets would accrete gas at whatever rate the disk provides (Lissauer et al., 2009, Icarus, 199, 338). We performed 2D and 3D hydrodynamical calculations of a Jupiter-Saturn system tidally interacting with a protoplanetary disk and investigated how gas accretion affects their migration history. We assumed initial conditions shown to result in the outward migration of non-accreting planets and recovered such scenario. We then allowed the planets to accrete gas at a disk-limited rate. In agreement with estimates derived for single planets, the assumed disk conditions lead to a mass-doubling time scale of the exterior planet that is 6-9 times as short as that of interior planet. Under these circumstances, the exterior planet's mass would quickly approach the interior planet's mass, halting outward migration. Planetary accretion is responsible for another effect that conspires against outward migration. A stationary disk, in which the accretion rate is nearly constant over its radius, would have a reduced surface density S within the orbit of an accreting planet. The reduction factor depends on the planet's accretion efficiency E, i.e., the ratio of the accretion rate onto the planet to the accretion rate through the disk interpolated at the planet's position. One can show that dMe/dt~(1+E)dMi/dt, where dMe/dt and dMi/dt are the disk accretion rates exterior and interior of the planet's orbit (Lubow & D'Angelo, 2006, Astrophys. J., 641, 526). In a stationary disk, S is proportional to the accretion rate and therefore Si~Se/(1+E), reducing the positive Lindblad torques acting on the planet. We estimated the accretion efficiency allowing for accretion onto Jupiter, but not onto Saturn, and found that E~5-6. Including accretion onto Saturn would likely yield a smaller Si/Se ratio. We simulated the migration of the two planets in such a stationary disk and found that it is directed toward the star and occurs on a time scale of order the viscous diffusion time scale.

  10. arXiv:astro-ph/0603196v18Mar2006 Disk-Planet Interactions During Planet Formation

    E-print Network

    Metchev, Stanimir

    and University of Stockholm The discovery of close orbiting extrasolar giant planets led to extensive studies orbiting planets intially formed at several AU, inward migration times for objects in the earth mass range a population of close orbiting giant planets with periods of typically a few days, the so called 'hot Jupiters

  11. Lone Planet Under a Cosmic Magnifying Glass - Duration: 45 seconds.

    NASA Video Gallery

    This artist's animation illustrates the technique used for finding free-floating, Jupiter-mass planets in space. Astronomers found evidence for 10 of these worlds, thought to have been ejected earl...

  12. Discovery and Mass Measurements of a Cold, Sub-Neptune Mass Planet and Its Host Star

    NASA Technical Reports Server (NTRS)

    Barry, Richard K., Jr.

    2011-01-01

    The gravitational microlensing exoplanet detection method is uniquely sensitive to cold, low-mass planets which orbit beyond the snow-line, where the most massive planets are thought to form. The early statistical results from microlensing indicate that Neptune-Saturn mass planets located beyond the snow-line are substantially more common than their counterparts in closer orbits that have found by the Doppler radial velocity method. We present the discovery of the planet MOA-2009-BLG-266Lb, which demonstrates that the gravitational microlensing method also has the capability to measure the masses of cold, low-mass planets. The mass measurements of the host star and the planet are made possible by the detection of the microlensing parallax signal due to the orbital motion or the Earth as well as observations from the EPOXI spacecraft in a Heliocentric orbit. The microlensing light curve indicates a planetary host star mass of M(sun) = 0.54 + / - 0.05M(sun) located at a distance of DL= 2.94 _ 0.21 kpc, orbited by a planet of mass mp= 9.8 +/-1.1M(Earth) with a semi-major axis of a = 3.1(+1.9-0.4)MAU.

  13. Discovery and Mass Measurements of a Cold, 10-Earth Mass Planet and Its Host Star

    NASA Technical Reports Server (NTRS)

    Barry, Richard K.; Muraki, Y.; Han, C.; Bennett, D. P.; Gaudi, B. S.

    2011-01-01

    We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method. This planet has a mass of mp = 10.4 +/- M(Earth) and orbits a star of Mstar = 0.56 +/- 0.09 M(Sun) at a semi-major axis of a = 3.2 + 1.9/-0.5 AU, and an orbital period of 7.6 +7.7/-1.5 yrs. The planet and host star mass measurements are due to the measurement of the microlensing parallax effect. This measurement was primarily due to the orbital motion of the Earth, but the analysis also demonstrates the capability measure micro lensing parallax with the Deep Impact (or EPOXI) spacecraft in a Heliocentric orbit. The planet mass and orbital distance are similar to predictions for the critical core mass needed to accrete a substantial gaseous envelope, and thus may indicate that this planet is a failed gas giant. This and future microlensing detections will test planet formation theory predictions regarding the prevalence and masses of such planets

  14. The Galileo probe mass spectrometer: composition of Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.; Way, S. H.

    1996-01-01

    The composition of the jovian atmosphere from 0.5 to 21 bars along the descent trajectory was determined by a quadrupole mass spectrometer on the Galileo probe. The mixing ratio of He (helium) to H2 (hydrogen), 0.156, is close to the solar ratio. The abundances of methane, water, argon, neon, and hydrogen sulfide were measured; krypton and xenon were detected. As measured in the jovian atmosphere, the amount of carbon is 2.9 times the solar abundance relative to H2, the amount of sulfur is greater than the solar abundance, and the amount of oxygen is much less than the solar abundance. The neon abundance compared with that of hydrogen is about an order of magnitude less than the solar abundance. Isotopic ratios of carbon and the noble gases are consistent with solar values. The measured ratio of deuterium to hydrogen (D/H) of (5 +/- 2) x 10(-5) indicates that this ratio is greater in solar-system hydrogen than in local interstellar hydrogen, and the 3He/4He ratio of (1.1 +/- 0.2) x 10(-4) provides a new value for protosolar (solar nebula) helium isotopes. Together, the D/H and 3He/4He ratios are consistent with conversion in the sun of protosolar deuterium to present-day 3He.

  15. Gravitational Influence of a Large Captured Body on the Stability of Jupiter’s Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Ohtsuki, Keiji; Okayama, Hiroaki

    2015-11-01

    The Trojan asteroids orbit the Sun about the L4 and L5 Lagrangian points of Jupiter. These objects have a wide range of eccentricities and inclinations, and are thought to be captured planetesimals. Since the origin of the Trojan asteroids is expected to provide clues to the dynamical evolution of the planets and small bodies in the Solar System, various models have been proposed, e.g., capture due to gas drag from the solar nebula, capture during Jupiter’s mass growth, or capture during smooth migration of Jupiter. However, such models failed to reproduce some important characteristics of the present Trojan asteroids, such as the total mass of the Trojans, the distribution of orbital elements, or the distribution of the libration amplitudes. On the other hand, recent models for the formation of the Solar System suggest that the giant planets likely experienced significant radial migration and orbital instability after their formation. Studies of capture of Trojan asteroids based on such models of giant planet migration show that icy planetesimals originally in the outer Solar System can be captured into Jupiter’s Trojan regions, and the present total mass as well as the observed orbital characteristics of the Trojan asteroids can be explained in such models. However, in such studies of capture of the Trojan asteroids, asteroids were treated as test particles, thus gravitational interactions between planetesimals are not taken into account. Although effects of gravitational interactions between sufficiently small asteroids may reasonably be neglected, there may have been significantly large objects in the original swam of Trojan asteroids immediately after their capture. In the present study, we assume that a large body was captured into Jupiter’s Trojan region, and examine its dynamical influence on other Trojan asteroids using orbital integration. From the results of our calculations, we will discuss constraints on the mass of bodies existed in the Trojan swarm in the past.

  16. Origins of Hot Jupiters, Revisited

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter; Laughlin, Greg

    2015-12-01

    Hot Jupiters, giant extrasolar planets with orbital periods less than ~10 days, have long been thought to form at large radial distances (a > 2AU) in protostellar disks, only to subsequently experience large-scale inward migration to the small orbital radii at which they are observed. Here, we propose that a substantial fraction of the hot Jupiter population forms in situ, with the Galactically prevalent short-period super-Earths acting as the source population. Our calculations suggest that under conditions appropriate to the inner regions of protostellar disks, rapid gas accretion can be initiated for solid cores of 10-20 Earth masses, in line with the conventional picture of core-nucleated accretion. This formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional planets, reminiscent of those observed in large numbers by NASA’s Kepler Mission and Doppler velocity surveys. However, dynamical interactions during the early stages of planetary systems' evolutionary lifetimes tend to increase the mutual inclinations of exterior, low-mass companions to hot Jupiters, making transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  17. GIANT PLANET FORMATION BY DISK INSTABILITY IN LOW MASS DISKS?

    SciTech Connect

    Boss, Alan P.

    2010-12-20

    Forming giant planets by disk instability requires a gaseous disk that is massive enough to become gravitationally unstable and able to cool fast enough for self-gravitating clumps to form and survive. Models with simplified disk cooling have shown the critical importance of the ratio of the cooling to the orbital timescales. Uncertainties about the proper value of this ratio can be sidestepped by including radiative transfer. Three-dimensional radiative hydrodynamics models of a disk with a mass of 0.043 M{sub sun} from 4 to 20 AU in orbit around a 1 M{sub sun} protostar show that disk instabilities are considerably less successful in producing self-gravitating clumps than in a disk with twice this mass. The results are sensitive to the assumed initial outer disk (T{sub o}) temperatures. Models with T{sub o} = 20 K are able to form a single self-gravitating clump, whereas models with T{sub o} = 25 K form clumps that are not quite self-gravitating. These models imply that disk instability requires a disk with a mass of at least {approx}0.043 M{sub sun} inside 20 AU in order to form giant planets around solar-mass protostars with realistic disk cooling rates and outer-disk temperatures. Lower mass disks around solar-mass protostars must rely upon core accretion to form inner giant planets.

  18. A rocky planet transiting a nearby low-mass star

    E-print Network

    Berta-Thompson, Zachory K; Charbonneau, David; Newton, Elisabeth R; Dittmann, Jason A; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michaël; Jehin, Emmanuël; Stark, Antony A; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno C; Udry, Stéphane; Wünsche, Anaël

    2015-01-01

    M-dwarf stars -- hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun -- are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the plane...

  19. Fast migration of low-mass planets in radiative discs

    E-print Network

    Pierens, Arnaud

    2015-01-01

    Low-mass planets are known to undergo Type I migration and this process must have played a key role during the evolution of planetary systems. Analytical formulae for the disc torque have been derived assuming that the planet evolves on a fixed circular orbit. However, recent work has shown that in isothermal discs, a migrating protoplanet may also experience dynamical corotation torques that scale with the planet drift rate. The aim of this study is to examine whether dynamical corotation torques can also affect the migration of low-mass planets in non-isothermal discs. We performed 2D radiative hydrodynamical simulations to examine the orbital evolution outcome of migrating protoplanets as a function of disc mass. We find that a protoplanet can enter a fast migration regime when it migrates in the direction set by the entropy-related horseshoe drag and when the Toomre stability parameter is less than a threshold value below which the horseshoe region contracts into a tadpole-like region. In that case, an un...

  20. ATMOSPHERIC CHEMISTRY IN GIANT PLANETS, BROWN DWARFS, AND LOW-MASS DWARF STARS. III. IRON, MAGNESIUM, AND SILICON

    SciTech Connect

    Visscher, Channon; Lodders, Katharina; Fegley, Bruce E-mail: lodders@wustl.ed

    2010-06-20

    We use thermochemical equilibrium calculations to model iron, magnesium, and silicon chemistry in the atmospheres of giant planets, brown dwarfs, extrasolar giant planets (EGPs), and low-mass stars. The behavior of individual Fe-, Mg-, and Si-bearing gases and condensates is determined as a function of temperature, pressure, and metallicity. Our equilibrium results are thus independent of any particular model atmosphere. The condensation of Fe metal strongly affects iron chemistry by efficiently removing Fe-bearing species from the gas phase. Monatomic Fe is the most abundant Fe-bearing gas throughout the atmospheres of EGPs and L dwarfs, and in the deep atmospheres of giant planets and T dwarfs. Mg- and Si-bearing gases are effectively removed from the atmosphere by forsterite (Mg{sub 2}SiO{sub 4}) and enstatite (MgSiO{sub 3}) cloud formation. Monatomic Mg is the dominant magnesium gas throughout the atmospheres of EGPs and L dwarfs and in the deep atmospheres of giant planets and T dwarfs. Silicon monoxide (SiO) is the most abundant Si-bearing gas in the deep atmospheres of brown dwarfs and EGPs, whereas SiH{sub 4} is dominant in the deep atmosphere of Jupiter and other gas giant planets. Several other Fe-, Mg-, and Si-bearing gases become increasingly important with decreasing effective temperature. In principle, a number of Fe, Mg, and Si gases are potential tracers of weather or diagnostic of temperature in substellar atmospheres.

  1. Atmospheric Escape from Hot Jupiters

    E-print Network

    A. Lecavelier des Etangs; A. Vidal-Madjar; J. C. McConnell; G. Hebrard

    2004-03-16

    The extra-solar planet HD209458b has been found to have an extended atmosphere of escaping atomic hydrogen (Vidal-Madjar et al. 2003), suggesting that ``hot Jupiters'' closer to their parent stars could evaporate. Here we estimate the atmospheric escape (so called evaporation rate) from hot Jupiters and their corresponding life time against evaporation. The calculated evaporation rate of HD209458b is in excellent agreement with the HI Lyman-alpha observations. We find that the tidal forces and high temperatures in the upper atmosphere must be taken into account to obtain reliable estimate of the atmospheric escape. Because of the tidal forces, we show that there is a new escape mechanism at intermediate temperatures at which the exobase reaches the Roche lobe. From an energy balance, we can estimate plausible values for the planetary exospheric temperatures, and thus obtain typical life times of planets as a function of their mass and orbital distance.

  2. An Overview of the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Grammier, Richard S.

    2006-01-01

    Arriving in orbit around the planet Jupiter in 2016 after a five-year journey, the Juno spacecraft will begin a one-year investigation of the gas giant in order to understand its origin and evolution by determining its water abundance and constraining its core mass. In addition, Juno will map the planet's magnetic and gravitational fields, map its atmosphere, and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras. Juno will discriminate among different models for giant planet formation. These investigations will be conducted over the course of thirty-two 11-day elliptical polar orbits of the planet. The orbits are designed to avoid Jupiter's highest radiation regions. The spacecraft is a spinning, solar-powered system carrying a complement of eight science instruments for conducting the investigations. The spacecraft systems and instruments take advantage of significant design and operational heritage from previous space missions.

  3. On the Relation Between Hot Jupiters & the Roche Limit

    E-print Network

    Eric B. Ford; Frederic A. Rasio

    2005-12-29

    Many of the known extrasolar planets are ``hot Jupiters,'' giant planets with orbital periods of just a few days. We use the observed distribution of hot Jupiters to constrain the location of its inner edge in the mass--period diagram. If we assume a slope corresponding to the classical Roche limit, then we find that the edge corresponds to a separation close to_twice_ the Roche limit, as expected if the planets started on highly eccentric orbits that were later circularized. In contrast, any migration scenario would predict an inner edge right at the Roche limit, which applies to planets approaching on nearly circular orbits. However, the current sample of hot Jupiters is not sufficient to provide a precise constraint simultaneously on both the location and slope of the inner edge.

  4. Mass Losses Of Co, Cs And Hcn On Jupiter/sl9

    NASA Astrophysics Data System (ADS)

    Moreno, Raphael; Marten, A.

    2006-09-01

    Since comet Shoemaker-Levy 9 (SL9) collided with Jupiter in 1994, the IRAM 30-m Telescope (Pico Veleta, Spain) and the 15-m JCMT (Mauna Kea,Hawaii) have regularly observed Jupiter at millimeter/submillimeter wavelengths. Molecular trace species such as HCN, CO, CS and their isotopomers have been detected in the upper atmosphere since the collision. Because of the high spectral resolution attained, our data allow one to infer both temperature and abundances in Jupiter's stratosphere with a maximum spatial resolution of 10 arcsec. We have used all these data to monitor the latitudinal spreading since the impacts occurred (Marten et al. 1995), to look for changes in their abundances with time (Moreno et al. 2001, 2003) and to determine several isotopic ratios (Matthews et al. 2002). Data taken in 2004 have shown that latitudinal distributions of all these species were almost homogeneous 10 years after impacts, as predicted by Moreno et al. 2003. Moreover, compared to 1998 results, respective mass loss factors as high as 2-7 have been determined for the three molecular main compounds (Moreno et al. 2005). In order to follow-up our monitoring, new disk mapping observations took place in May 2006 using the IRAM-30m Telescope. Here we report the results of the recent measurements of CO, CS and HCN, and also the search for new species: H2CO, H2CS, CH3CN, CH3OH. Such trace compounds could have explained the mass losses observed in 2004, but no clear detections have been obtained after reasonable integration times. Estimates of the new CO, CS and HCN total masses and upper limits for the trace species searched for will be presented. The loss mechanisms will be discussed. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  5. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    E-print Network

    Chadney, J M; Unruh, Y C; Koskinen, T T; Sanz-Forcada, J

    2014-01-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - epsilon Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale th...

  6. Extraterrestrial Life: Problem Set #1 Solutions 1) Explain briefly how the terrestrial planets (such as the Earth) differ from

    E-print Network

    Armitage, Phil

    Extraterrestrial Life: Problem Set #1 Solutions 1) Explain briefly how the terrestrial planets (such as the Earth) differ from the giant planets (such as Jupiter). Describe how these differences planets are low mass planets (the most massive is the Earth) whose composition is predominantly rock

  7. The Jupiter Twin HD 154345b

    E-print Network

    J. T. Wright; G. W. Marcy; R. P. Butler; S. S. Vogt; G. W. Henry; H. Isaacson; A. W. Howard

    2009-01-12

    We announce the discovery of a twin of Jupiter orbiting the slightly metal-poor ([Fe/H] = -0.1) nearby (d = 18 pc) G8 dwarf HD 154345. This planet has a minimum mass of 0.95 Jupiter masses and a 9.2 year, circular orbit with radius 4.2 AU. There is currently little or no evidence for other planets in the system, but smaller or exterior planets cannot yet be ruled out. We also detect a ~ 9-year activity cycle in this star photometrically and in chromospheric emission. We rule out activity cycles as the source of the radial velocity variations by comparison with other cycling late-G dwarfs.

  8. A rocky planet transiting a nearby low-mass star.

    PubMed

    Berta-Thompson, Zachory K; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R; Dittmann, Jason A; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michaël; Jehin, Emmanuël; Stark, Antony A; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno C; Udry, Stéphane; Wünsche, Anaël

    2015-11-12

    M-dwarf stars--hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun--are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the planet is too hot to be habitable but is cool enough to support a substantial atmosphere, one that has probably been considerably depleted of hydrogen. Because the host star is nearby and only 21 per cent the radius of the Sun, existing and upcoming telescopes will be able to observe the composition and dynamics of the planetary atmosphere. PMID:26560298

  9. A rocky planet transiting a nearby low-mass star

    NASA Astrophysics Data System (ADS)

    Berta-Thompson, Zachory K.; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R.; Dittmann, Jason A.; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michaël; Jehin, Emmanuël; Stark, Antony A.; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno C.; Udry, Stéphane; Wünsche, Anaël

    2015-11-01

    M-dwarf stars—hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun—are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the planet is too hot to be habitable but is cool enough to support a substantial atmosphere, one that has probably been considerably depleted of hydrogen. Because the host star is nearby and only 21 per cent the radius of the Sun, existing and upcoming telescopes will be able to observe the composition and dynamics of the planetary atmosphere.

  10. MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING

    SciTech Connect

    Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M.; Backer, D. C.; Bailes, M.; Bhat, N. D. R.; Van Straten, W.; Coles, W.; Demorest, P. B.; Ferdman, R. D.; Purver, M. B.; Folkner, W. M.; Hotan, A. W.; Kramer, M.; Lommen, A. N.; Nice, D. J.; Stairs, I. H.

    2010-09-10

    High-precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2) x10{sup -4} M {sub sun}, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.

  11. SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

    SciTech Connect

    Wu Yanqin; Lithwick, Yoram

    2011-07-10

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term 'secular migration') explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the 'warm Jupiters' at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  12. TOWARD CHEMICAL CONSTRAINTS ON HOT JUPITER MIGRATION

    SciTech Connect

    Madhusudhan, Nikku; Amin, Mustafa A.; Kennedy, Grant M.

    2014-10-10

    The origin of hot Jupiters—gas giant exoplanets orbiting very close to their host stars—is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses. In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily explained by giant planets forming at large orbital separations, either by core accretion or gravitational instability, and migrating to close-in orbits via disk-free mechanisms involving dynamical encounters. Such planets also contain solar or super-solar C/O ratios. On the contrary, hot Jupiters with super-solar O and C abundances can be explained by a variety of formation-migration pathways which, however, lead to solar or sub-solar C/O ratios. Current estimates of low oxygen abundances in hot Jupiter atmospheres may be indicative of disk-free migration mechanisms. We discuss open questions in this area which future studies will need to investigate.

  13. Planet traps and first planets: The critical metallicity for gas giant formation

    SciTech Connect

    Hasegawa, Yasuhiro; Hirashita, Hiroyuki E-mail: hirashita@asiaa.sinica.edu.tw

    2014-06-10

    The ubiquity of planets poses an interesting question: when are first planets formed in galaxies? We investigate this by adopting a theoretical model where planet traps are combined with the standard core accretion scenario in which the efficiency of forming planetary cores directly relates to the metallicity ([Fe/H]) in disks. Three characteristic exoplanetary populations are examined: hot Jupiters, exo-Jupiters around 1 AU, and low-mass planets in tight orbits, such as super-Earths. We statistically compute planet formation frequencies (PFFs), as well as the orbital radius (?R{sub rapid}?) within which gas accretion becomes efficient enough to form Jovian planets, as a function of metallicity (–2 ? [Fe/H] ?–0.6). We show that the total PFFs for these three populations increase steadily with metallicity. This is the direct outcome of the core accretion picture. For the metallicity range considered here, the population of low-mass planets dominates Jovian planets. The Jovian planets contribute to the PFFs above [Fe/H] ? –1. We find that the hot Jupiters form more efficiently than the exo-Jupiters at [Fe/H] ? –0.7. This arises from the slower growth of planetary cores and their more efficient radial inward transport by the host traps in lower metallicity disks. We show that the critical metallicity for forming Jovian planets is [Fe/H] ? –1.2 by comparing ?R{sub rapid}? of hot Jupiters and low-mass planets. The comparison intrinsically links to the different gas accretion efficiency between these two types of planets. Therefore, this study implies that important physical processes in planet formation may be tested by exoplanet observations around metal-poor stars.

  14. In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

    E-print Network

    Batygin, Konstantin; Laughlin, Gregory P

    2015-01-01

    Hot Jupiters, giant extrasolar planets with orbital periods shorter than ~10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we propose that in contrast with this picture, a substantial fraction of the hot Jupiter population formed in situ via the core accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by Super-Earth type planets, comprising 10-20 Earth masses of refractory composition material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ~100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems' lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring p...

  15. Conditions for water ice lines and Mars-mass exomoons around accreting super-Jovian planets at 1-20 AU from Sun-like stars

    NASA Astrophysics Data System (ADS)

    Heller, R.; Pudritz, R.

    2015-06-01

    Context. The first detection of a moon around an extrasolar planet (an "exomoon") might be feasible with NASA's Kepler or ESA's upcoming PLATO space telescopes or with the future ground-based European Extremely Large Telescope. To guide observers and to use observational resources most efficiently, we need to know where the largest, most easily detected moons can form. Aims: We explore the possibility of large exomoons by following the movement of water (H2O) ice lines in the accretion disks around young super-Jovian planets. We want to know how the different heating sources in those disks affect the location of the H2O ice lines as a function of stellar and planetary distance. Methods: We simulate 2D rotationally symmetric accretion disks in hydrostatic equilibrium around super-Jovian exoplanets. The energy terms in our semi-analytical framework - (1) viscous heating; (2) planetary illumination; (3) accretional heating of the disk; and (4) stellar illumination - are fed by precomputed planet evolution models. We consider accreting planets with final masses between 1 and 12 Jupiter masses at distances between 1 and 20 AU to a solar type star. Results: Accretion disks around Jupiter-mass planets closer than about 4.5 AU to Sun-like stars do not feature H2O ice lines, whereas the most massive super-Jovians can form icy satellites as close as 3 AU to Sun-like stars. We derive an empirical formula for the total moon mass as a function of planetary mass and stellar distance and predict that super-Jovian planets forming beyond about 5 AU can host Mars-mass moons. Planetary illumination is the major heat source in the final stages of accretion around Jupiter-mass planets, whereas disks around the most massive super-Jovians are similarly heated by planetary illumination and viscous heating. This indicates a transition towards circumstellar accretion disks, where viscous heating dominates in the stellar vicinity. We also study a broad range of circumplanetary disk parameters for planets at 5.2 AU and find that the H2O ice lines are universally between about 15 and 30 Jupiter radii in the final stages of accretion when the last generation of moons is supposed to form. Conclusions: If the abundant population of super-Jovian planets around 1 AU formed in situ, then these planets should lack the previously predicted population of giant icy moons, because those planets' disks did not host H2O ice in the final stages of accretion. But in the more likely case that these planets migrated to their current locations from beyond about 3 to 4.5 AU they might be orbited by large, water-rich moons. In this case, Mars-mass ocean moons might be common in the stellar habitable zones. Future exomoon detections and non-detections can provide powerful constraints on the formation and migration history of giant exoplanets.

  16. Deep Atmosphere Ammonia Mixing Ratio at Jupiter from the Galileo Probe Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Mahaffy, P. R.; Niemann, H. B.; Demick, J. E.

    1999-01-01

    New laboratory studies employing the Engineering Unit (EU) of the Galileo Probe Mass Spectrometer (GPMS) have resulted in a substantial reduction in the previously reported upper limit on the ammonia mixing ratio derived from the GPMS experiment at Jupiter. This measurement is complicated by background ammonia contributions in the GPMS during direct atmospheric sampling produced from the preceding gas enrichment experiments. These backgrounds can be quantified with the data from the EU studies when they are carried out in a manner that duplicates the descent profile of pressure and enrichment cell loading. This background is due to the tendency of ammonia to interact strongly with the walls of the mass spectrometer and on release to contribute to the gas being directly directed into the ion source from the atmosphere through a capillary pressure reduction leak. It is evident from the GPMS and other observations that the mixing ratio of ammonia at Jupiter reaches the deep atmosphere value at substantially higher pressures than previously assumed. This is a likely explanation for the previously perceived discrepancy between ammonia values derived from ground based microwave observations and those obtained from attenuation of the Galileo Probe radio signal.

  17. HAT-P-55b: A Hot Jupiter Transiting a Sun-like Star

    E-print Network

    Juncher, D; Hartman, J D; Bakos, G Á; Bieryla, A; Kovács, T; Boisse, I; Latham, D W; Kovács, G; Bhatti, W; Csubry, Z; Penev, K; de Val-Borro, M; Falco, E; Torres, G; Noyes, R W; Lázár, J; Papp, I; Sári, P

    2015-01-01

    We report the discovery of a new transiting extrasolar planet, HAT-P-55b. The planet orbits a V = 13.207 +/- 0.039 sun-like star with a mass of 1.013 +/- 0.037 solar masses, a radius of 1.011 +/- 0.036 solar radii and a metallicity of -0.03 +/- 0.08. The planet itself is a typical hot Jupiter with a period of 3.5852467 +/- 0.0000064 days, a mass of 0.582 +/- 0.056 Jupiter masses and a radius of 1.182 +/- 0.055 Jupiter radii. This discovery adds to the increasing sample of transiting planets with measured bulk densities, which is needed to put constraints on models of planetary structure and formation theories.

  18. Occurrence rate of low-mass planets around nearby M dwarfs

    NASA Astrophysics Data System (ADS)

    Jones, Hugh

    2015-08-01

    We re-analyse archival radial velocities of nearby M dwarfs to constrain low-amplitude Keplerian signals. We apply a variety of signal detection criteria and photometric monitoring to assess the number of planet candidates in the sample. We use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. Our results indicate that M dwarfs are hosts to an abundance of low-mass planets and the occurrence rate of planets less massive than 10 Earth masses is of the order of one planet per star and that planets are common in the stellar habitable zones of M dwarfs.

  19. Periodic mass extinctions and the Planet X model reconsidered

    NASA Astrophysics Data System (ADS)

    Whitmire, Daniel P.

    2016-01-01

    The 27 Myr period in the fossil extinction record has been confirmed in modern data bases dating back 500 Myr, which is twice the time interval of the original analysis from 30 years ago. The surprising regularity of this period has been used to reject the Nemesis model. A second model based on the Sun's vertical Galactic oscillations has been challenged on the basis of an inconsistency in period and phasing. The third astronomical model originally proposed to explain the periodicity is the Planet X model in which the period is associated with the perihelion precession of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated to mass extinctions, a trans-Neptunian super-Earth planet has been proposed to explain the observation that the inner Oort cloud objects Sedna and 2012VP113 have perihelia that lie near the ecliptic plane. In this Letter, we reconsider the Planet X model in light of the confluence of the modern palaeontological and outer Solar system dynamical evidence.

  20. Periodic mass extinctions and the Planet X model reconsidered

    E-print Network

    Whitmire, Daniel P

    2015-01-01

    The 27 Myr periodicity in the fossil extinction record has been confirmed in modern data bases dating back 500 Myr, which is twice the time interval of the original analysis from thirty years ago. The surprising regularity of this period has been used to reject the Nemesis model. A second model based on the sun's vertical galactic oscillations has been challenged on the basis of an inconsistency in period and phasing. The third astronomical model originally proposed to explain the periodicity is the Planet X model in which the period is associated with the perihelion precession of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated to mass extinctions, a trans-Neptunian super-Earth planet has been proposed to explain the observation that the inner Oort cloud objects Sedna and 2012VP113 have perihelia that lie near the ecliptic plane. In this Letter we reconsider the Planet X model in light of the confluence of the modern palaeontological and outer solar system dynamical evidence.

  1. A decreased probability of habitable planet formation around low-mass stars

    E-print Network

    Sean N. Raymond; John Scalo; Victoria Meadows

    2007-07-11

    Smaller terrestrial planets (habitable" planets can form is the availability of solid planet-forming material. We use dynamical simulations of terrestrial planet formation from planetary embryos and simple scaling arguments to explore the implications of correlations between terrestrial planet mass, disk mass, and the mass of the parent star. We assume that the protoplanetary disk mass scales with stellar mass as Mdisk ~ f Mstar^h, where f measures the relative disk mass, and 1/2 planets, based on current models and observations for M stars. We assume the mass of a planet formed in some annulus of a disk with given parameters is proportional to the disk mass in that annulus, and show with a suite of simulations of late-stage accretion that the adopted prescription is surprisingly accurate. Our results suggest that the fraction of systems with sufficient disk mass to form > 0.3 Earth mass habitable planets decreases for low-mass stars for every realistic combination of parameters. This "habitable fraction" is small for stellar masses below a mass in the interval 0.5 to 0.8 Solar masses, depending on disk parameters, an interval that excludes most M stars. Radial mixing and therefore water delivery are inefficient in lower-mass disks commonly found around low-mass stars, such that terrestrial planets in the habitable zones of most low-mass stars are likely to be small and dry.

  2. Planet Formation

    NASA Astrophysics Data System (ADS)

    Chambers, J. E.

    2003-12-01

    Modern theories for the origin of the planets are based on observations of the solar system and star-forming regions elsewhere in the galaxy, together with the results of numerical models. Some key observations are: - The solar system contains eight large planets with roughly circular, coplanar orbits lying 0.4-30 AU from the Sun. There are few locations between the planets where additional large objects could exist on stable orbits. - The major planets are grouped: small volatile-poor planets lie close to the Sun, with large volatile-rich planets further out. The main asteroid belt (2-4 AU from the Sun) is substantially depleted in mass with respect to other regions. - The planets and asteroids are depleted in volatile elements compared to the Sun. The degree of fractionation decreases with distance: the terrestrial planets and inner-belt asteroids are highly depleted in volatiles, the outer-belt asteroids are less so, while many satellites in the outer solar system are ice rich. Primitive CI meteorites (probably from the outer asteroid belt) have elemental abundances very similar to the Sun except for highly volatile elements. - Ancient solid surfaces throughout the solar system are covered in impact craters (e.g., the Moon, Mercury, Mars, Callisto). Most of the planets have large axial tilts with respect to their orbits. Earth possesses a large companion with a mass ˜1% that of the planet itself. - The terrestrial planets and many asteroids have undergone differentiation. There is strong evidence that Saturn is highly centrally condensed, with a core of mass ˜10M?, and weaker evidence that Jupiter has a core of similar mass. These cores have masses comparable to Uranus and Neptune. - Meteorites from the main asteroid belt show evidence that they once contained short-lived radioactive isotopes with half-lives <10 Myr. The main components of primitive meteorites (chondrules and refractory inclusions) have sizes clustered around 1 mm. These components appear to have undergone rapid melting and cooling. - Young stars generally exist in gas- and dust-rich environments. Many young stars possess massive, optically thick disks with diameters of 10-1,000 AU. These disks are inferred to have lifetimes of ˜1-10 Myr. - At least 4% of main sequence (ordinary) stars have planetary-mass companions. The companions have masses of 0.1-10 Jupiter masses (the lower limit is the current detection threshhold), and orbital distances from 0.05 AU to 5 AU (the upper limit is the current detection threshhold).These observations have led to the development and refinement of a theory in which the planets formed from a disk-shaped protoplanetary nebula (Laplace) by pairwise accretion of small solid bodies (Safranov, 1969). A variant of the standard model invokes the gravitational collapse of portions of this disk to form gas giant planets directly. It should be pointed out that the standard model is designed to explain the planets observed in the solar system. Attempts to account for planetary systems recently discovered orbiting other stars suggest that planet formation is likely to differ in several respects from one system to another.

  3. Jupiter Formation, Life in the Slow Lane?

    NASA Astrophysics Data System (ADS)

    Hamilton, D. P.; Kortenkamp, S. J.; Fleming, H. J.

    2000-10-01

    The growth of Jupiter, as predicted by the favored core-accretion model of planetary formation, is a two-stage process. First an ? 10 Earth mass core is formed by runaway growth of an icy protoplanet, after which the protoplanet gravitationally captures over 300 Earth masses of gas directly from the Solar Nebula. The process is thought to take ? 107 years. An alternate possibility, the mass-instability hypothesis, has recently experienced a resurgence of interest due to the increasingly rapid discoveries of unusual jovian-mass extrasolar planets. A sufficiently massive gas disk can become unstable and form an azimuthally asymmetric blob destined to become a giant planet in as short as 102 years. Which process actually formed Jupiter? Trojan asteroids, very numerous and with close dynamical links to Jupiter, are ideally suited to provide critical clues about Jupiter's formation. A number of processes could potentially capture objects into 1:1 resonance with Jupiter including radial migration, gas drag, mass accretion, collisional emplacement, disk tides, and gravitational scattering by massive protoplanetary embryos. We are currently undertaking a systematic study of each of these processes. The mass-instability scenario, in its simplest form, posits a fully-formed Jupiter with L4 and L5 points clear of gas and unpopulated with Trojans. By contrast, in the core-accretion model, precursor material is already trapped in 1:1 resonance with the jovian core. Furthermore, subsequent mass accretion and gas drag systematically concentrate matter toward the L4 and L5 points. The emerging theme is that a populous Trojan region is more easily achieved by the slower core-accretion model.

  4. Discovery of a Jupiter/Saturn analog with gravitational microlensing.

    PubMed

    Gaudi, B S; Bennett, D P; Udalski, A; Gould, A; Christie, G W; Maoz, D; Dong, S; McCormick, J; Szymanski, M K; Tristram, P J; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; Depoy, D L; Han, C; Kaspi, S; Lee, C-U; Mallia, F; Natusch, T; Pogge, R W; Park, B-G; Abe, F; Bond, I A; Botzler, C S; Fukui, A; Hearnshaw, J B; Itow, Y; Kamiya, K; Korpela, A V; Kilmartin, P M; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N J; Sako, T; Saito, To; Sato, S; Skuljan, L; Sullivan, D J; Sumi, T; Sweatman, W L; Yock, P C M; Albrow, M D; Allan, A; Beaulieu, J-P; Burgdorf, M J; Cook, K H; Coutures, C; Dominik, M; Dieters, S; Fouqué, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2008-02-15

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common. PMID:18276883

  5. Conditions for water ice lines and Mars-mass exomoons around accreting super-Jovian planets at 1 - 20 AU from Sun-like stars

    E-print Network

    Heller, René

    2015-01-01

    Exomoon detections might be feasible with NASA's Kepler or ESA's upcoming PLATO mission or the ground-based E-ELT. To use observational resources most efficiently we need to know where the largest, most easily detected moons can form. We explore the possibility of large exomoons by following the movement of water (H2O) ice lines in the accretion disks around young super-Jovian planets. We want to know how different heating sources in those disks affect the H2O ice lines. We simulate 2D rotationally symmetric accretion disks in hydrostatic equilibrium around super-Jovian exoplanets. The energy terms in our semi-analytical model -- (1) viscous heating, (2) planetary illumination, (3) accretional heating, and (4) stellar illumination -- are fed by precomputed planet evolution tracks. We consider planets accreting 1 to 12 Jupiter masses at distances between 1 and 20 AU to a Sun-like star. Accretion disks around Jupiter-mass planets closer than ~4.5 AU to Sun-like stars do not feature H2O ice lines, but the most m...

  6. Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars

    NASA Astrophysics Data System (ADS)

    Leconte, Jérémy; Wu, Hanbo; Menou, Kristen; Murray, Norman

    2015-02-01

    Planets in the habitable zone of lower-mass stars are often assumed to be in a state of tidally synchronized rotation, which would considerably affect their putative habitability. Although thermal tides cause Venus to rotate retrogradely, simple scaling arguments tend to attribute this peculiarity to the massive Venusian atmosphere. Using a global climate model, we show that even a relatively thin atmosphere can drive terrestrial planets’ rotation away from synchronicity. We derive a more realistic atmospheric tide model that predicts four asynchronous equilibrium spin states, two being stable, when the amplitude of the thermal tide exceeds a threshold that is met for habitable Earth-like planets with a 1-bar atmosphere around stars more massive than ~0.5 to 0.7 solar mass. Thus, many recently discovered terrestrial planets could exhibit asynchronous spin-orbit rotation, even with a thin atmosphere.

  7. Volatile-Rich Earth-Mass Planets in the Habitable Zone

    E-print Network

    Marc J. Kuchner

    2003-08-28

    A small planet is not necessarily a terrestrial planet. Planets that form beyond the snow line with too little mass to seed rapid gas accretion (planets should migrate inward by interacting with a circumstellar disk or with other planets. Such objects can retain their volatiles for billions of years or longer at ~1 AU as their atmospheres undergo slow hydrodynamic escape. These objects could appear in future surveys for extrasolar Earth analogs.

  8. Hydrogen EOS at Megabar Pressures and the Search for Jupiter's Core

    NASA Astrophysics Data System (ADS)

    Hubbard, William B.

    The interior structure of Jupiter serves as a benchmark for an entire astrophysical class of liquid-metallic hydrogen-rich objects with masses ranging from ˜0.1MJ to ˜80MJ (1MJ = Jupiter mass = 1.9e30g), comprising hydrogen-rich giant planets (mass < 13MJ) and brown dwarfs (mass > 13MJ but ˜<80MJ), the so-called substellar objects (SSOs). Formation of giant planets may involve nucleated collapse of nebular gas onto a solid, dense core of mass ˜0.04MJ rather than a stellar-like gravitational instability. Thus, detection of a primordial core in Jupiter is a prime objective for understanding the mode of origin of extrasolar giant planets and other SSOs. A basic method for core detection makes use of direct modeling of Jupiter's external gravitational potential terms in response to rotational and tidal perturbations, and is highly sensitive to the thermodynamics of hydrogen at multi-megabar pressures. The present-day core masses of Jupiter and Saturn may be larger than their primordial core masses due to sedimentation of elements heavier than hydrogen. We show that there is a significant contribution of such sedimented mass to Saturn's core mass. The sedimentation contribution to Jupiter's core mass will be smaller and could be zero.

  9. Architectural and Chemical Insights into the Origin of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Schlaufman, Kevin C.

    2015-08-01

    The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. This problem has been with us for 20 years, long enough for significant progress to have been made, and also for a great deal of "lore" to have accumulated about the properties of these planets. Among this lore are the widespread beliefs that hot Jupiters are less likely be in multiple giant planet systems than longer-period giant planets, and that there is an excess of close-in giant planets with orbital periods near three days. I will show that in these cases the lore is not supported by the best data available today: hot Jupiters are not lonely and there is no evidence of a three-day pile-up. I will also show that stellar sodium abundance is inversely proportional to the probability that a star hosts a short-period giant planet. This observation is best explained by the effect of decreasing sodium abundance on protoplanetary disk structure and reveals that planet-disk interactions are critical for the existence of short-period giant planets. Collectively, these results support the importance of disk migration for the origin of short-period giant planets.

  10. THE ANGLO-AUSTRALIAN PLANET SEARCH. XXII. TWO NEW MULTI-PLANET SYSTEMS

    SciTech Connect

    Wittenmyer, Robert A.; Horner, J.; Salter, G. S.; Tinney, C. G.; Bailey, J.; Tuomi, Mikko; Zhang, Z.; Butler, R. P.; Jones, H. R. A.; O'Toole, S. J.; Carter, B. D.; Jenkins, J. S.; Vogt, S. S.; Rivera, Eugenio J.

    2012-07-10

    We report the detection of two new planets from the Anglo-Australian Planet Search. These planets orbit two stars each previously known to host one planet. The new planet orbiting HD 142 has a period of 6005 {+-} 427 days, and a minimum mass of 5.3 M{sub Jup}. HD 142c is thus a new Jupiter analog: a gas-giant planet with a long period and low eccentricity (e = 0.21 {+-} 0.07). The second planet in the HD 159868 system has a period of 352.3 {+-} 1.3 days and m sin i = 0.73 {+-} 0.05 M{sub Jup}. In both of these systems, including the additional planets in the fitting process significantly reduced the eccentricity of the original planet. These systems are thus examples of how multiple-planet systems can masquerade as moderately eccentric single-planet systems.

  11. TERRESTRIAL PLANET FORMATION DURING THE MIGRATION AND RESONANCE CROSSINGS OF THE GIANT PLANETS

    SciTech Connect

    Lykawka, Patryk Sofia; Ito, Takashi

    2013-08-10

    The newly formed giant planets may have migrated and crossed a number of mutual mean motion resonances (MMRs) when smaller objects (embryos) were accreting to form the terrestrial planets in the planetesimal disk. We investigated the effects of the planetesimal-driven migration of Jupiter and Saturn, and the influence of their mutual 1:2 MMR crossing on terrestrial planet formation for the first time, by performing N-body simulations. These simulations considered distinct timescales of MMR crossing and planet migration. In total, 68 high-resolution simulation runs using 2000 disk planetesimals were performed, which was a significant improvement on previously published results. Even when the effects of the 1:2 MMR crossing and planet migration were included in the system, Venus and Earth analogs (considering both orbits and masses) successfully formed in several runs. In addition, we found that the orbits of planetesimals beyond a {approx} 1.5-2 AU were dynamically depleted by the strengthened sweeping secular resonances associated with Jupiter's and Saturn's more eccentric orbits (relative to the present day) during planet migration. However, this depletion did not prevent the formation of massive Mars analogs (planets with more than 1.5 times Mars's mass). Although late MMR crossings (at t > 30 Myr) could remove such planets, Mars-like small mass planets survived on overly excited orbits (high e and/or i), or were completely lost in these systems. We conclude that the orbital migration and crossing of the mutual 1:2 MMR of Jupiter and Saturn are unlikely to provide suitable orbital conditions for the formation of solar system terrestrial planets. This suggests that to explain Mars's small mass and the absence of other planets between Mars and Jupiter, the outer asteroid belt must have suffered a severe depletion due to interactions with Jupiter/Saturn, or by an alternative mechanism (e.g., rogue super-Earths)

  12. A CORRELATION BETWEEN HOST STAR ACTIVITY AND PLANET MASS FOR CLOSE-IN EXTRASOLAR PLANETS?

    SciTech Connect

    Poppenhaeger, K.; Schmitt, J. H. M. M.

    2011-07-01

    The activity levels of stars are influenced by several stellar properties, such as stellar rotation, spectral type, and the presence of stellar companions. Analogous to binaries, planetary companions are also thought to be able to cause higher activity levels in their host stars, although at lower levels. Especially in X-rays, such influences are hard to detect because coronae of cool stars exhibit a considerable amount of intrinsic variability. Recently, a correlation between the mass of close-in exoplanets and their host star's X-ray luminosity has been detected, based on archival X-ray data from the ROSAT All-Sky Survey. This finding has been interpreted as evidence for star-planet interactions. We show in our analysis that this correlation is caused by selection effects due to the flux limit of the X-ray data used and due to the intrinsic planet detectability of the radial velocity method, and thus does not trace possible planet-induced effects. We also show that the correlation is not present in a corresponding complete sample derived from combined XMM-Newton and ROSAT data.

  13. The interplanetary and near-Jupiter meteoroid environments

    NASA Technical Reports Server (NTRS)

    Humes, D. H.; Alvarez, J. M.; Oneal, R. L.; Kinard, W. H.

    1974-01-01

    The meteoroid penetration detectors on the Pioneer 10 spacecraft recorded 67 meteoroid penetrations through the 25-micron stainless steel test material while the spacecraft was between 1.0 and 5.1 AU. Ten of these penetrations occurred during the encounter with Jupiter. The cumulative spatial density of meteoroids with masses greater than 2 nanograms has been calculated from these data for interplanetary space and for the near-Jupiter space. The spatial density is found to be essentially constant in interplanetary space between 1 and 5 AU, approximately 1 meteoroid per cubic km, and 1-2 orders of magnitude greater near Jupiter. There was no increase in the spatial density of meteoroids in the asteroid belt and hence no evidence that there is a significant asteroidal component of 2-nanogram meteoroids. It is uncertain whether the meteoroids detected near Jupiter were in orbit about Jupiter or were gravitationally focused toward the planet from solar orbits.

  14. Transiting exoplanets from the CoRoT space mission. XVII. The hot Jupiter CoRoT-17b: a very old planet

    NASA Astrophysics Data System (ADS)

    Csizmadia, Sz.; Moutou, C.; Deleuil, M.; Cabrera, J.; Fridlund, M.; Gandolfi, D.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Bruntt, H.; Carone, L.; Carpano, S.; Cavarroc, C.; Cochran, W.; Deeg, H. J.; Díaz, R. F.; Dvorak, R.; Endl, M.; Erikson, A.; Ferraz-Mello, S.; Fruth, Th.; Gazzano, J.-C.; Gillon, M.; Guenther, E. W.; Guillot, T.; Hatzes, A.; Havel, M.; Hébrard, G.; Jehin, E.; Jorda, L.; Léger, A.; Llebaria, A.; Lammer, H.; Lovis, C.; MacQueen, P. J.; Mazeh, T.; Ollivier, M.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Titz-Weider, R.; Wuchterl, G.

    2011-07-01

    We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30 MJup and a radius of 1.02 ± 0.07 RJup, while its mean density is 2.82 ± 0.38 g/cm3. CoRoT-17b is in a circular orbit with a period of 3.7681 ± 0.0003 days. The host star is an old (10.7 ± 1.0 Gyr) main-sequence star, which makes it an intriguing object for planetary evolution studies. The planet's internal composition is not well constrained and can range from pure H/He to one that can contain ~380 earth masses of heavier elements. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  15. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter Benjamin; Knutson, Heather; Batygin, Konstantin; Fulton, Benjamin James; Burrows, Adam Seth; Fortney, Jonathan J.

    2016-01-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit due to the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Due to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity is in part dictated by its Love number, i.e. the degree of central mass concentration in its interior. We can therefore directly constrain the fraction of HAT-P-13b's mass contained in its core by measuring its orbital eccentricity. This method offers considerable advantages over the standard approach of inferring core size based on mass and radius measurements alone. In this study we derive new constraints on the value of HAT-P-13b's eccentricity by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that the eccentricity of HAT-P-13b is 0.00696 ± 0.00096. We then use octupole-order secular perturbation theory to find that the corresponding Love number is 0.31 (+0.11, -0.05). Applying structural evolution models, we then find, with 68% confidence, that the core mass lies between 0-25 Earth masses, with a most likely value of the core mass of 11 Earth masses. This is the tightest constraint, to date, on the core mass of an exoplanet. We also compare the measured secondary eclipse depths, in the 3.6 and 4.5 micron bands, to the predictions of a suite of atmosphere models and find that the depths are best matched by models with a dayside temperature inversion and relatively efficient day-night circulation.

  16. CAPTURE OF TROJANS BY JUMPING JUPITER

    SciTech Connect

    Nesvorny, David; Vokrouhlicky, David; Morbidelli, Alessandro

    2013-05-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to {approx}5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) Multiplication-Sign 10{sup -7} for each particle in the original transplanetary disk, implying that the disk contained (3-4) Multiplication-Sign 10{sup 7} planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M{sub disk} {approx} 14-28 M{sub Earth}, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  17. Observed properties of extrasolar planets.

    PubMed

    Howard, Andrew W

    2013-05-01

    Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small planets between the sizes of Earth and Neptune substantially outnumber Jupiter-sized planets. The survey measurements support the core accretion model, in which planets form by the accumulation of solids and then gas in protoplanetary disks. The diversity of exoplanetary characteristics demonstrates that most of the gross features of the solar system are one outcome in a continuum of possibilities. The most common class of planetary system detectable today consists of one or more planets approximately one to three times Earth's size orbiting within a fraction of the Earth-Sun distance. PMID:23641110

  18. Microlensing search for extrasolar planets

    E-print Network

    A. Cassan; D. Kubas

    2006-12-01

    Microlensing has recently proven to be a valuable tool to search for extrasolar planets of Neptune- to super-Earth-mass planets at orbits of few AU. Since planetary signals are of very short duration, an intense and continuous monitoring is required, which is achieved by PLANET : ``Probing Lensing Anomalies NETwork''. Up to now the detection number amounts to four, one of them being OGLE 2005-BLG-390Lb, an extrasolar planet of only ~5.5 M_earth orbiting its M-dwarf host star at ~2.6 AU. For non-planetary microlensing events observed from 1995 to 2006, we compute detection efficiency diagrams which can then be used to derive an estimate of the limit on the Galactic abundance of sub-Jupiter-mass planets, as well as relative abundance of Neptune-like planets.

  19. Extrasolar binary planets. I. Formation by tidal capture during planet-planet scattering

    SciTech Connect

    Ochiai, H.; Nagasawa, M.; Ida, S.

    2014-08-01

    We have investigated (1) the formation of gravitationally bounded pairs of gas-giant planets (which we call 'binary planets') from capturing each other through planet-planet dynamical tide during their close encounters and (2) the subsequent long-term orbital evolution due to planet-planet and planet-star quasi-static tides. For the initial evolution in phase 1, we carried out N-body simulations of the systems consisting of three Jupiter-mass planets taking into account the dynamical tide. The formation rate of the binary planets is as much as 10% of the systems that undergo orbital crossing, and this fraction is almost independent of the initial stellarcentric semimajor axes of the planets, while ejection and merging rates sensitively depend on the semimajor axes. As a result of circularization by the planet-planet dynamical tide, typical binary separations are a few times the sum of the physical radii of the planets. After the orbital circularization, the evolution of the binary system is governed by long-term quasi-static tide. We analytically calculated the quasi-static tidal evolution in phase 2. The binary planets first enter the spin-orbit synchronous state by the planet-planet tide. The planet-star tide removes angular momentum of the binary motion, eventually resulting in a collision between the planets. However, we found that the binary planets survive the tidal decay for the main-sequence lifetime of solar-type stars (?10 Gyr), if the binary planets are beyond ?0.3 AU from the central stars. These results suggest that the binary planets can be detected by transit observations at ? 0.3 AU.

  20. Jupiter's Decisive Role in the Inner Solar System's Early Evolution

    E-print Network

    Batygin, Konstantin

    2015-01-01

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days, and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 AU to a ~ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ~ 10-100 km planetesimals into low-order mean-motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any pre-existing short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the p...

  1. Jupiter's decisive role in the inner Solar System's early evolution.

    PubMed

    Batygin, Konstantin; Laughlin, Greg

    2015-04-01

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ? 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ? 10-100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution. PMID:25831540

  2. A Definition for Giant Planets Based on the Mass-Density Relationship

    E-print Network

    Rauer, Artie P Hatzes Heike

    2015-01-01

    We present the mass-density relationship (log M - log rho) for objects with masses ranging from planets (M ~ 0.01 M_Jup) through stars (M > 0.08 M_Sun). This relationship shows three distinct regions separated by a change in slope in log M -- log rho plane. In particular, objects with masses in the range 0.3 M_Jup to 60 M_Jup follow a tight linear relationship with no distinguishing feature to separate the low mass end (giant planets) from the high mass end (brown dwarfs). The distinction between giant planets and brown dwarfs thus seems arbitrary. We propose a new definition of giant planets based simply on changes in the slope of the log $M$ versus log rho relationship. By this criterion, objects with masses less than ~ 0.3 M_Jup are low mass planets, either icy or rocky. Giant planets cover the mass range 0.3 M_Jup to 60 M_Jup. Analogous to the stellar main sequence, objects on the upper end of the giant planet sequence (brown dwarfs) can simply be referred to as "high mass giant planets", while planets wi...

  3. Planets in the Asteroid Belt

    NASA Astrophysics Data System (ADS)

    Chambers, J. E.

    1999-09-01

    If Jupiter and Saturn formed via accretion of a solid core, and capture of an H-He envelope, the amount of solid material in the proto-planetary disk must have been substantially more than the `minimum mass' nebula. In this case the region now occupied by the main-belt asteroids must have contained (i) several Earth masses of solids, and (ii) planet-sized bodies. One scenario for removing these `asteroidal planets' is that they scattered one another into unstable resonances with the giant planets. N-body integrations show that the modern Jupiter and Saturn can clear 90% of the original mass in the main belt within 100 million years. However, in the course of ejecting asteroidal planets, the orbital eccentricities of the giant planets decrease to almost zero. This implies Jupiter and Saturn initially had more eccentric orbits (roughly e=0.1), which increases the size and strength of the unstable resonances. In this case, they clear 90% of the mass in the asteroid belt in only a few million years. At this point, a few asteroidal planets remain, and these can survive for several hundred million years before being removed. During this time, they are likely to inject a steady stream of smaller asteroids into unstable resonances with the giant planets. Many of these asteroids will enter the region occupied by the terrestrial planets. This scenario may simultaneously solve 2 observational problems: (i) how to remove most of the solid material in the asteroid belt quickly enough, and with few collisions, so that the fragile crust of Vesta is preserved, and (ii) how to continue to supply large impactors to the terrestrial planets until the end of the late heavy bombardment.

  4. STELLAR PARAMETERS AND METALLICITIES OF STARS HOSTING JOVIAN AND NEPTUNIAN MASS PLANETS: A POSSIBLE DEPENDENCE OF PLANETARY MASS ON METALLICITY

    SciTech Connect

    Ghezzi, L.; Cunha, K.; De Araujo, F. X.; De la Reza, R.; Smith, V. V.; Schuler, S. C.

    2010-09-10

    The metal content of planet-hosting stars is an important ingredient that may affect the formation and evolution of planetary systems. Accurate stellar abundances require the determinations of reliable physical parameters, namely, the effective temperature, surface gravity, microturbulent velocity, and metallicity. This work presents the homogeneous derivation of such parameters for a large sample of stars hosting planets (N = 117), as well as a control sample of disk stars not known to harbor giant, closely orbiting planets (N = 145). Stellar parameters and iron abundances are derived from an automated analysis technique developed for this work. As previously found in the literature, the results in this study indicate that the metallicity distribution of planet-hosting stars is more metal rich by {approx}0.15 dex when compared to the control sample stars. A segregation of the sample according to planet mass indicates that the metallicity distribution of stars hosting only Neptunian-mass planets (with no Jovian-mass planets) tends to be more metal poor in comparison with that obtained for stars hosting a closely orbiting Jovian planet. The significance of this difference in metallicity arises from a homogeneous analysis of samples of FGK dwarfs which do not include the cooler and more problematic M dwarfs. This result would indicate that there is a possible link between planet mass and metallicity such that metallicity plays a role in setting the mass of the most massive planet. Further confirmation, however, must await larger samples.

  5. THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

    SciTech Connect

    Guo, J. H.

    2010-04-01

    By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass loss could interfere with tidal evolution. In an upper limit case (beta = 3), a significant portion of mass may be evaporated in a long evolution timescale. Evidence of greater modification of the planets with an initial separation of about 0.1 AU than those with a = 0.15 AU can be found in this model. With the assumption of a large initial eccentricity, the planets with initial mass <=1 M{sub J} and initial distance of about 0.1 AU could not survive. With the supposition of beta = 1.1, we find that the loss process has an effect on the planets with low mass at a {approx} 0.05 AU. In both cases, the effect of evaporation on massive planets can be neglected. Also, heating efficiency and initial eccentricity have significant influence on tidal evolution. We find that even low heating efficiency and initial eccentricity have a significant effect on tidal evolution. Our analysis shows that evaporation on planets with different initial masses can accelerate (decelerate) the tidal evolution due to the increase (decrease) in tide of the planet (star). Consequently, the effect of evaporation cannot be neglected in evolutionary calculations of close-in planets. The physical parameters of HD 209458b can be fitted by our model.

  6. Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometer

    NASA Technical Reports Server (NTRS)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.

    1998-01-01

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.

  7. Chemical composition measurements of the atmosphere of jupiter with the galileo probe mass spectrometer

    NASA Astrophysics Data System (ADS)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for ^3He/^4He, D/H, ^13C/^12C, ^20Ne/^22Ne, ^38Ar/^36Ar and for isotopes of both Kr and Xe.

  8. Jassi - Jupiter Microwave Sounder Mission Concept

    NASA Astrophysics Data System (ADS)

    Bolton, S. J.; Jassi Team

    Jupiter contains key evidence regarding the nature of the proto-planetary disk, or solar nebula, out of which the solar system formed. During formation, Jupiter accreted both a large mass of gas directly from the nebula and considerable amounts-perhaps several tens of Earth masses-of solid planetesimals (Guillot 1999). The abundance of oxygen and nitrogen are crucial pieces of information required to understand where and how Jupiter and its planetesimal inventory formed. These two principal heavy elements, together with the Galileo probe determinations of the abundances of other elements, will enable important generalizations regarding the nature and frequency of incidence of giant planet formation around solar-type stars. The ratio to H of all the heavy elements determined by the Galileo entry probe, N,S,C,Ar,Kr, and Xe were found enriched relative to their solar values by a factor of 2-3. This was interpreted to imply that Jupiter formed from planetesimals that trapped volatile gases in a very cold environment (Owen et al., 1999). It was suggested that either the region of the solar nebula where Jupiter formed was much colder than mod- els or observations of analogous extra-solar proto-planetary disks suggest, or Jupiter formed quite far out and migrated inward, or the components of the icy planetesimals that formed the planet avoided vaporization when entering the solar nebula (Owen et al. 1999). The measurement of nitrogen by Galileo is fraught with uncertainty and does not match ground-based measurements. Moreover, the mixing ratio of water, which, in the form of icy planetesimals, was presumably the original carrier of the volatiles containing the heavy elements, has not yet been determined in the well-mixed part of Jupiter's atmosphere. The cold planetesimal hypothesis predicts the water ratio to H enriched by the same factor of ~3 relative to solar as the other heavy elements are. Recently, Gautier et al. (2001) proposed that the volatiles were delivered by clathrate- hydrates, and that the O/H ratio would be at least 3 times the prediction of the cold planetesimal model. Water determination is thus extremely important. Ar/N and O/N ratio will help determine whether nitrogen entered Jupiter in the form of ammonia or as molecular nitrogen. This is a key constraint on the environment in which the plan- etesimals formed. This paper will discuss a novel microwave remote sensing technique from a fly-by spacecraft for determining the water and ammonia abundances to sev- eral hundred bar pressure levels in Jupiter's atmosphere. The mission in the form of a polar flyby also provides important constraints on Jupiter's interior structure and atmospheric dynamics.

  9. DEUTERIUM BURNING IN MASSIVE GIANT PLANETS AND LOW-MASS BROWN DWARFS FORMED BY CORE-NUCLEATED ACCRETION

    SciTech Connect

    Bodenheimer, Peter; Fortney, Jonathan J.; Saumon, Didier E-mail: gennaro.dangelo@nasa.gov E-mail: jfortney@ucolick.org

    2013-06-20

    Using detailed numerical simulations, we study the formation of bodies near the deuterium-burning limit according to the core-nucleated giant planet accretion scenario. The objects, with heavy-element cores in the range 5-30 M{sub Circled-Plus }, are assumed to accrete gas up to final masses of 10-15 Jupiter masses (M{sub Jup}). After the formation process, which lasts 1-5 Myr and which ends with a ''cold-start'', low-entropy configuration, the bodies evolve at constant mass up to an age of several Gyr. Deuterium burning via proton capture is included in the calculation, and we determined the mass, M{sub 50}, above which more than 50% of the initial deuterium is burned. This often-quoted borderline between giant planets and brown dwarfs is found to depend only slightly on parameters, such as core mass, stellar mass, formation location, solid surface density in the protoplanetary disk, disk viscosity, and dust opacity. The values for M{sub 50} fall in the range 11.6-13.6 M{sub Jup}, in agreement with previous determinations that do not take the formation process into account. For a given opacity law during the formation process, objects with higher core masses form more quickly. The result is higher entropy in the envelope at the completion of accretion, yielding lower values of M{sub 50}. For masses above M{sub 50}, during the deuterium-burning phase, objects expand and increase in luminosity by one to three orders of magnitude. Evolutionary tracks in the luminosity versus time diagram are compared with the observed position of the companion to Beta Pictoris.

  10. Atmospheric Escape From Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth A.; Chiang, Eugene I.; Murray, Norman

    2009-03-01

    Photoionization heating from ultraviolet (UV) radiation incidents on the atmospheres of hot Jupiters may drive planetary mass loss. Observations of stellar Lyman-? (Ly?) absorption have suggested that the hot Jupiter HD 209458b is losing atomic hydrogen. We construct a model of escape that includes realistic heating and cooling, ionization balance, tidal gravity, and pressure confinement by the host star wind. We show that mass loss takes the form of a hydrodynamic (Parker) wind, emitted from the planet's dayside during lulls in the stellar wind. When dayside winds are suppressed by the confining action of the stellar wind, nightside winds might pick up if there is sufficient horizontal transport of heat. A hot Jupiter loses mass at maximum rates of ~2 × 1012 g s-1 during its host star's pre-main-sequence phase and ~2 × 1010 g s-1 during the star's main-sequence lifetime, for total maximum losses of ~0.06% and ~0.6% of the planet's mass, respectively. For UV fluxes F UV lsim 104 erg cm-2 s-1, the mass-loss rate is approximately energy limited and scales as \\dot{M} ? F_UV^{0.9}. For larger UV fluxes, such as those typical of T Tauri stars, radiative losses and plasma recombination force \\dot{M} to increase more slowly as F 0.6 UV. Dayside winds are quenched during the T Tauri phase because of confinement by overwhelming stellar wind pressure. During this early stage, nightside winds can still blow if the planet resides outside the stellar Alfvén radius; otherwise, even nightside winds are stifled by stellar magnetic pressure, and mass loss is restricted to polar regions. We conclude that while UV radiation can indeed drive winds from hot Jupiters, such winds cannot significantly alter planetary masses during any evolutionary stage. They can, however, produce observable signatures. Candidates for explaining why the Lyman-? photons of HD 209458 are absorbed at Doppler-shifted velocities of ±100 km s-1 include charge-exchange in the shock between the planetary and stellar winds.

  11. Constraints on the Mass of Planets with Water of Nebular Origin

    NASA Astrophysics Data System (ADS)

    Ikoma, M.; Genda, H.

    2005-08-01

    Detection of many extrasolar planets has stimulated us to make a systematic study of planet formation. Theoretical studies on the accretion and dynamical evolution of planets have constrained the masses and periods of planets in extrasolar systems. From an astrobiological point of view, special attention has been paid to probabilities of the existence of planets in the habitable zone where a planet can keep liquid water above its surface. Few studies have, however, discussed how likely a planet acquires a sufficient amount of water. Although there are several sources of water on terrestrial planets, we focus on an idea that water is produced on a planet by oxidation of a hydrogen-rich atmosphere, the nebular gas being attracted gravitationally by the planet. The process of water production could work if a planet captures a sufficient amount of hydrogen, has a molten surface (i.e., magma oceans), and contains some oxide. Our extensive investigation of properties of the hydrogen-rich atmosphere shows the former two conditions are fulfilled on an Earth-size planet for a wide range of parameters. Moreover, some oxide such as FeO is common material in planets, as long as the C/O ratio of extrasolar systems is less than unity. Therefore, sufficient water on an Earth-sized rocky planet is a natural consequence of planet formation. The range of masses of those potentially-habitable planets is also constrained. This research was supported by the 21st Century COE Program ``How to build habitable planets", Tokyo Institute of Technology, sponsored by the Ministry of Education, Culture, Sports, Technology and Science (MEXT), Japan.

  12. The occultation of beta Scorpii by Jupiter. VI - The masses of beta Scorpii A1 and A2

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; Rages, K.; Veverka, J.

    1975-01-01

    From images of the spectroscopic binary beta Sco A, formed by the Jovian atmosphere during its 1971 May 13 occultation by Jupiter, the angular separation of the binary components was found to be 0.001496 plus of minus 0.000018 arcsec. The combination of this measurement, the elements of the spectroscopic orbit, and the parallax determination of Bertiau (1958) yields masses of 21.1 plus or minus 3.2 solar masses for the primary (B0.5 V) and 12.7 plus or minus 1.9 solar masses for the secondary. New observations are suggested for improving the accuracy of the mass determinations.

  13. The Gemini Planet Imager Exoplanet Survey and the discovery of the young Jupiter analog 51 Eridani b

    NASA Astrophysics Data System (ADS)

    Macintosh, Bruce; Gemini Planet Imager Exoplanet Survey

    2016-01-01

    The Gemini Planet Imager Exoplanet Survey has been began in November 2014 and has surveyed more than 100 young nearby stars. I will present an updated status of the survey, including instrument performance and completeness limits. We reported our first new exoplanet discovery, the 20 Myr planet 51 Eri b, in August of 2015. J and H band spectra show that it is among the coolest and lowest-luminosity exoplanets yet imaged, with strong methane absorption and a luminosity consistent with low-entropy formation. I will give an overview of the planet's properties, and results from observations in the second half of 2015.

  14. The Mass-Metallicity Relation for Giant Planets

    E-print Network

    Thorngren, Daniel P; Lopez, Eric D

    2015-01-01

    Exoplanet discoveries of recent years have provided a great deal of new data for studying the bulk compositions of giant planets. Here we identify 38 transiting giant planets ($20 M_\\oplus 50 M_\\oplus$) suggest significant amounts of heavy elements in H/He envelopes, rather than cores, such that metal-enriched giant planet atmospheres should be the rule.

  15. The ELODIE and SOPHIE Search for Northern Extrasolar Planets: Jupiter-Analogs around Sun-Like Stars

    NASA Astrophysics Data System (ADS)

    Boisse, I.; Pepe, F.; Perrier, C.; Queloz, D.; Bouchy, F.; Santos, N. C.

    2014-04-01

    We present radial-velocity measurements (RV) obtained in one of the numbers of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Observatoire de Haute-Provence. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years.

  16. The ELODIE and SOPHIE search for northern extrasolar planets: Jupiter-analogs around Sun-like stars

    NASA Astrophysics Data System (ADS)

    Boisse, I.; Pepe, F.; Perrier, C.; Queloz, D.; Bouchy, F.; Santos, N. C.

    2012-12-01

    We present radial-velocity measurements (RV) obtained in one of a number of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Observatoire de Haute-Provence. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years.

  17. DIRECTLY IMAGING TIDALLY POWERED MIGRATING JUPITERS

    SciTech Connect

    Dong Subo; Katz, Boaz; Socrates, Aristotle

    2013-01-10

    Upcoming direct-imaging experiments may detect a new class of long-period, highly luminous, tidally powered extrasolar gas giants. Even though they are hosted by {approx} Gyr-'old' main-sequence stars, they can be as 'hot' as young Jupiters at {approx}100 Myr, the prime targets of direct-imaging surveys. They are on years-long orbits and presently migrating to 'feed' the 'hot Jupiters'. They are expected from 'high-e' migration mechanisms, in which Jupiters are excited to highly eccentric orbits and then shrink semimajor axis by a factor of {approx}10-100 due to tidal dissipation at close periastron passages. The dissipated orbital energy is converted to heat, and if it is deposited deep enough into the atmosphere, the planet likely radiates steadily at luminosity L {approx} 100-1000 L{sub Jup}(2 Multiplication-Sign 10{sup -7}-2 Multiplication-Sign 10{sup -6} L{sub Sun }) during a typical {approx} Gyr migration timescale. Their large orbital separations and expected high planet-to-star flux ratios in IR make them potentially accessible to high-contrast imaging instruments on 10 m class telescopes. {approx}10 such planets are expected to exist around FGK dwarfs within {approx}50 pc. Long-period radial velocity planets are viable candidates, and the highly eccentric planet HD 20782b at maximum angular separation {approx}0.''08 is a promising candidate. Directly imaging these tidally powered Jupiters would enable a direct test of high-e migration mechanisms. Once detected, the luminosity would provide a direct measurement of the migration rate, and together with mass (and possibly radius) estimate, they would serve as a laboratory to study planetary spectral formation and tidal physics.

  18. Influence of solar flares and CME on the gaseous envelopes of hot Jupiter exoplanets

    NASA Astrophysics Data System (ADS)

    Bisikalo, Dmitry; Cherenkov, Alexander

    2015-08-01

    Hot Jupiters, i.e. exoplanets having masses comparable to the mass of Jupiter and semimajor axes shorter than 0.1~AU, have a number of outstanding features, caused mostly by their proximity to the host star. As a matter of fact, the atmospheres of several dozens of these planets fill their Roche lobes, which results in a powerful outflow of material from the planet toward the host star. In addition, since the planet orbits at a short distance, its orbital velocity is supersonic, which causes the formation of a bow shock ahead of the planet. These effects substantially change the mechanism of interaction between the planet's gaseous envelope (atmosphere) and the stellar wind. In this paper, we investigate the flow pattern in the vicinity of a typical hot Jupiter by using 3D gas dynamic simulations. By considering the star-planet interaction we study variations in the structure of the hot Jupiter's envelope and estimate the variations of atmosphere’s mass-loss rate caused by the influence of typical solar flares and coronal mass ejections.

  19. THE LICK-CARNEGIE EXOPLANET SURVEY: A URANUS-MASS FOURTH PLANET FOR GJ 876 IN AN EXTRASOLAR LAPLACE CONFIGURATION

    SciTech Connect

    Rivera, Eugenio J.; Laughlin, Gregory; Vogt, Steven S.; Meschiari, Stefano; Haghighipour, Nader

    2010-08-10

    Continued radial velocity (RV) monitoring of the nearby M4V red dwarf star GJ 876 with Keck/High Resolution Echelle Spectrograph has revealed the presence of a Uranus-mass fourth planetary companion in the system. The new planet has a mean period of P{sub e} = 126.6 days (over the 12.6-year baseline of the RV observations), and a minimum mass of m{sub e} sin i{sub e} = 12.9 {+-} 1.7 M {sub +}. The detection of the new planet has been enabled by significant improvements to our RV data set for GJ 876. The data have been augmented by 36 new high-precision measurements taken over the past five years. In addition, the precision of all of the Doppler measurements have been significantly improved by the incorporation of a high signal-to-noise template spectrum for GJ 876 into the analysis pipeline. Implementation of the new template spectrum improves the internal rms errors for the velocity measurements taken during 1998-2005 from 4.1 m s{sup -1} to 2.5 m s{sup -1}. Self-consistent, N-body fits to the RV data set show that the four-planet system has an invariable plane with an inclination relative to the plane of the sky of i = 59.{sup 0}5. The fit is not significantly improved by the introduction of a mutual inclination between the planets 'b' and 'c', but the new data do confirm a non-zero eccentricity, e{sub d} = 0.207 {+-} 0.055 for the innermost planet, 'd'. In our best-fit coplanar model, the mass of the new component is m{sub e} = 14.6 {+-} 1.7 M {sub +}. Our best-fitting model places the new planet in a three-body resonance with the previously known giant planets (which have mean periods of P{sub c} = 30.4 and P{sub b} = 61.1 days). The critical argument, {psi}{sub Laplace} = {lambda} {sub c} - 3{lambda} {sub b} + 2{lambda} {sub e}, for the Laplace resonance librates with an amplitude of {Delta}{psi}{sub Laplace} = 40{sup 0} {+-} 13{sup 0} about {psi}{sub Laplace} = 0{sup 0}. Numerical integration indicates that the four-planet system is stable for at least a billion years (at least for the coplanar cases). This resonant configuration of three giant planets orbiting an M dwarf primary differs from the well-known Laplace configuration of the three inner Galilean satellites of Jupiter, which are executing very small librations about {psi}{sub Laplace} = 180{sup 0} and which never experience triple conjunctions. The GJ 876 system, by contrast, comes close to a triple conjunction between the outer three planets once per every orbit of the outer planet, 'e'.

  20. Mapping the stability field of Jupiter Trojans

    NASA Technical Reports Server (NTRS)

    Levison, H. F.; Shoemaker, E. M.; Wolfe, R. F.

    1991-01-01

    Jupiter Trojans are a remnant of outer solar system planetesimals captured into stable or quasistable libration about the 1:1 resonance with the mean motion of Jupiter. The observed swarms of Trojans may provide insight into the original mass of condensed solids in the zone from which the Jovian planets accumulated, provided that the mechanisms of capture can be understood. As the first step toward this understanding, the stability field of Trojans were mapped in the coordinate proper eccentricity, e(sub p), and libration amplitude, D. To accomplish this mapping, the orbits of 100 particles with e(sub p) in the range of 0 to 0.8 and D in the range 0 to 140 deg were numerically integrated. Orbits of the Sun, the four Jovian planets, and the massless particles were integrated as a full N-body system, in a barycentric frame using fourth order symplectic scheme.

  1. RV SURVEY FOR PLANETS OF BROWN DWARFS AND VERY LOW-MASS STARS IN CHA I

    E-print Network

    Joergens, Viki

    1 RV SURVEY FOR PLANETS OF BROWN DWARFS AND VERY LOW-MASS STARS IN CHA I Viki Joergens1 and Ralph, Germany ABSTRACT We have carried out a radial velocity (RV) search for planets and brown dwarf companions to very young (1-10 Myr) brown dwarfs and very low-mass stars in the Cha I star forming region

  2. THE McDONALD OBSERVATORY PLANET SEARCH: NEW LONG-PERIOD GIANT PLANETS AND TWO INTERACTING JUPITERS IN THE HD 155358 SYSTEM

    SciTech Connect

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Barnes, Stuart I.; Caldwell, Caroline; Wittenmyer, Robert A.; Horner, J.; Simon, Attila E.

    2012-04-10

    We present high-precision radial velocity (RV) observations of four solar-type (F7-G5) stars-HD 79498, HD 155358, HD 197037, and HD 220773-taken as part of the McDonald Observatory Planet Search Program. For each of these stars, we see evidence of Keplerian motion caused by the presence of one or more gas giant planets in long-period orbits. We derive orbital parameters for each system and note the properties (composition, activity, etc.) of the host stars. While we have previously announced the two-gas-giant HD 155358 system, we now report a shorter period for planet c. This new period is consistent with the planets being trapped in mutual 2:1 mean-motion resonance. We therefore perform an in-depth stability analysis, placing additional constraints on the orbital parameters of the planets. These results demonstrate the excellent long-term RV stability of the spectrometers on both the Harlan J. Smith 2.7 m telescope and the Hobby-Eberly telescope.

  3. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS

    SciTech Connect

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2010-03-10

    We develop an idealized dynamical model to predict the typical properties of outer extrasolar planetary systems, at radii comparable to the Jupiter-to-Neptune region of the solar system. The model is based upon the hypothesis that dynamical evolution in outer planetary systems is controlled by a combination of planet-planet scattering and planetary interactions with an exterior disk of small bodies ('planetesimals'). Our results are based on 5000 long duration N-body simulations that follow the evolution of three planets from a few to 10 AU, together with a planetesimal disk containing 50 M{sub +} from 10 to 20 AU. For large planet masses (M {approx}> M{sub Sat}), the model recovers the observed eccentricity distribution of extrasolar planets. For lower-mass planets, the range of outcomes in models with disks is far greater than that which is seen in isolated planet-planet scattering. Common outcomes include strong scattering among massive planets, sudden jumps in eccentricity due to resonance crossings driven by divergent migration, and re-circularization of scattered low-mass planets in the outer disk. We present the distributions of the eccentricity and inclination that result, and discuss how they vary with planet mass and initial system architecture. In agreement with other studies, we find that the currently observed eccentricity distribution (derived primarily from planets at a {approx}< 3 AU) is consistent with isolated planet-planet scattering. We explain the observed mass dependence-which is in the opposite sense from that predicted by the simplest scattering models-as a consequence of strong correlations between planet masses in the same system. At somewhat larger radii, initial planetary mass correlations and disk effects can yield similar modest changes to the eccentricity distribution. Nonetheless, strong damping of eccentricity for low-mass planets at large radii appears to be a secure signature of the dynamical influence of disks. Radial velocity measurements capable of detecting planets with K {approx} 5 m s{sup -1} and periods in excess of 10 years will provide constraints on this regime. Finally, we present an analysis of the predicted separation of planets in two-planet systems, and of the population of planets in mean-motion resonances (MMRs). We show that, if there are systems with {approx} Jupiter-mass planets that avoid close encounters, the planetesimal disk acts as a damping mechanism and populates MMRs at a very high rate (50%-80%). In many cases, resonant chains (in particular the 4:2:1 Laplace resonance) are set up among all three planets. We expect such resonant chains to be common among massive planets in outer planetary systems.

  4. A Systematic Study of the Final Masses of Gas Giant Planets

    E-print Network

    T. Tanigawa; M. Ikoma

    2007-05-30

    We construct an analytic model for the rate of gas accretion onto a planet embedded in a protoplanetary disk as a function of planetary mass, disk viscosity, disk scale height, and unperturbed surface density in order to study the long-term accretion and final masses of gas giant planets. We first derive an analytical formula for surface density profile near the planetary orbit from considerations of the balance of force and the dynamical stability. Using it in the empirical formula linking surface density with gas accretion rate that is derived based on hydrodynamic simulations of Tanigawa and Watanabe (2002, ApJ 586, 506), we then simulate the mass evolution of gas giant planets in viscously-evolving disks. We finally determine the final mass as a function of semi-major axis of the planet. We find that the disk can be divided into three regions characterized by different processes by which the final mass is determined. In the inner region, the planet grows quickly and forms a deep gap to suppress the growth by itself before disk dissipation. The final mass of the planet in this region is found to increase with the semi-major axis in a similar way to the mass given by the viscous condition for gap opening, but the former is larger by a factor of approximately 10 than the latter. In the intermediate region, viscous diffusion of the disk gas limits the gas accretion before the planet form a deep gap. The final mass can be up to the disk mass, when disk viscous evolution occurs faster than disk evaporation. In the outer region, planets capture only tiny amounts of gas within the lifetime of the disk to form Neptune-like planets. We derive analytic formulae for the final masses in the different regions and the locations of the boundaries, which are helpful to gain a systematic understanding of the masses of gas giant planets.

  5. The Europa Jupiter system mission

    NASA Astrophysics Data System (ADS)

    Clark, K.; Stankov, A.; Pappalardo, R. T.; Greeley, R.; Blanc, M.; Lebreton, J.-P.; van Houten, T.

    2009-04-01

    Europa Jupiter System Mission (EJSM)— would be an international mission that would achieve Decadal Survey and Cosmic Vision goals. NASA and ESA have concluded a joint study of a mission to Europa, Ganymede and the Jupiter system with orbiters developed by NASA and ESA; contributions by JAXA are also possible. The baseline EJSM architecture consists of two primary elements operating in the Jovian system: the NASA-led Jupiter Europa Orbiter (JEO), and the ESA-led Jupiter Ganymede Orbiter (JGO). JEO and JGO would execute an intricately choreographed exploration of the Jupiter System be-fore settling into orbit around Europa and Ganymede, respectively. JEO and JGO would carry eleven and ten complementary instruments, respectively, to monitor dynamic phenomena (such as Io's volcanoes and Jupi-ter's atmosphere), map the Jovian magnetosphere and its interactions with the Galilean satellites, and charac-terize water oceans beneath the ice shells of Europa and Ganymede. EJSM would fully addresses high priority science objectives identified by the National Research Coun-cil's (NRC's) Decadal Survey and ESA's Cosmic Vi-sion for exploration of the outer solar system. The De-cadal Survey recommended a Europa Orbiter as the highest priority outer planet flagship mission and also identified Ganymede as a highly desirable mission tar-get. EJSM would uniquely addresse several of the cen-tral themes of ESA's Cosmic Vision Programme, through its in-depth exploration of the Jupiter system and its evolution from origin to habitability. EJSM would investigate the potential habitability of the active ocean-bearing moons Europa and Gany-mede, detailing the geophysical, compositional, geo-logical, and external processes that affect these icy worlds. EJSM would also explore Io and Callisto, Jupi-ter's atmosphere, and the Jovian magnetosphere. By understanding the Jupiter system and unraveling its history, the formation and evolution of gas giant plan-ets and their satellites would be better known. Most important, EJSM would shed new light on the potential for the emergence of life in the celestial neighborhood and beyond. The EJSM mission architecture provides opportu-nities for coordinated synergistic observations by JEO and JGO of the Jupiter and Ganymede magnetospheres, the volcanoes and torus of Io, the atmosphere of Jupi-ter, and comparative planetology of icy satellites. Each spacecraft could and would conduct "stand-alone" measurements, including the detailed investigation of Europa and Ganymede, providing significant pro-grammatic flexibility. Although engineering advances are needed for JEO (radiation designs) and JGO, no new technologies would be required to execute either EJSM mission element. The development schedule for the mission is such that a technology developed by 2012 - 2013 could easily be incorporated if it enhances the mission capability. Risk mitigation activities are under way to ensure that the radiation designs are implemented in the lowest-risk approach. The baseline mission con-cepts include robust mass and power margins. The EJSM mission architecture provides the opti-mal balance between science, risk, and cost using three guiding principles: achieve Decadal science; builds on lessons learned; and leverages international collabora-tions.

  6. ON THE TIDAL ORIGIN OF HOT JUPITER STELLAR OBLIQUITY TRENDS

    SciTech Connect

    Dawson, Rebekah I.

    2014-08-01

    It is debated whether the two hot Jupiter populations—those on orbits misaligned from their host star's spin axis and those well-aligned—result from two migration channels or from two tidal realignment regimes. Here I demonstrate that equilibrium tides raised by a planet on its star can account for three observed spin-orbit alignment trends: the aligned orbits of hot Jupiters orbiting cool stars, the planetary mass cut-off for retrograde planets, and the stratification by planet mass of cool host stars' rotation frequencies. The first trend can be caused by strong versus weak magnetic braking (the Kraft break), rather than realignment of the star's convective envelope versus the entire star. The second trend can result from a small effective stellar moment of inertia participating in the tidal realignment in hot stars, enabling massive retrograde planets to partially realign to become prograde. The third trend is attributable to higher-mass planets more effectively counteracting braking to spin up their stars. Both hot and cool stars require a small effective stellar moment of inertia participating in the tidal realignment, e.g., an outer layer weakly coupled to the interior. I demonstrate via Monte Carlo that this model can match the observed trends and distributions of sky-projected misalignments and stellar rotation frequencies. I discuss implications for inferring hot Jupiter migration mechanisms from obliquities, emphasizing that even hot stars do not constitute a pristine sample.

  7. TIDAL AND MAGNETIC INTERACTIONS BETWEEN A HOT JUPITER AND ITS HOST STAR IN THE MAGNETOSPHERIC CAVITY OF A PROTOPLANETARY DISK

    SciTech Connect

    Chang, S.-H.; Gu, P.-G.; Bodenheimer, P. H.

    2010-01-10

    We present a simplified model to study the orbital evolution of a young hot Jupiter inside the magnetospheric cavity of a proto-planetary disk. The model takes into account the disk locking of stellar spin as well as the tidal and magnetic interactions between the star and the planet. We focus on the orbital evolution starting from the orbit in 2:1 resonance with the inner edge of the disk, followed by the inward and then outward orbital migration driven by the tidal and magnetic torques as well as the Roche-lobe overflow of the tidally inflated planet. The goal in this paper is to study how the orbital evolution inside the magnetospheric cavity depends on the cavity size, planet mass, and orbital eccentricity. In the present work, we only target the mass range from 0.7 to 2 Jupiter masses. In the case of the large cavity corresponding to the rotational period approx7 days, the planet of mass >1 Jupiter mass with moderate initial eccentricities (approx>0.3) can move to the region <0.03 AU from its central star in 10{sup 7} yr, while the planet of mass <1 Jupiter mass cannot. We estimate the critical eccentricity beyond which the planet of a given mass will overflow its Roche radius and finally lose all of its gas onto the star due to runaway mass loss. In the case of the small cavity corresponding to the rotational period approx3 days, all of the simulated planets lose all of their gas even in circular orbits. Our results for the orbital evolution of young hot Jupiters may have the potential to explain the absence of low-mass giant planets inside approx0.03 AU from their dwarf stars revealed by transit surveys.

  8. KEPLER-15b: A HOT JUPITER ENRICHED IN HEAVY ELEMENTS AND THE FIRST KEPLER MISSION PLANET CONFIRMED WITH THE HOBBY-EBERLY TELESCOPE

    SciTech Connect

    Endl, Michael; MacQueen, Phillip J.; Cochran, William D.; Brugamyer, Erik J.; Buchhave, Lars A.; Rowe, Jason; Lucas, Phillip; Isaacson, Howard; Bryson, Steve; Howell, Steve B.; Borucki, William J.; Caldwell, Douglas; Christiansen, Jessie L.; Haas, Michael R.; Fortney, Jonathan J.; Hansen, Terese; Ciardi, David R.; Everett, Mark; Ford, Eric B.; and others

    2011-11-01

    We report the discovery of Kepler-15b (KOI-128), a new transiting exoplanet detected by NASA's Kepler mission. The transit signal with a period of 4.94 days was detected in the quarter 1 (Q1) Kepler photometry. For the first time, we have used the High Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) to determine the mass of a Kepler planet via precise radial velocity (RV) measurements. The 24 HET/HRS RVs and 6 additional measurements from the Fibre-fed Echelle Spectrograph spectrograph at the Nordic Optical Telescope reveal a Doppler signal with the same period and phase as the transit ephemeris. We used one HET/HRS spectrum of Kepler-15 taken without the iodine cell to determine accurate stellar parameters. The host star is a metal-rich ([Fe/H] = 0.36 {+-} 0.07) G-type main-sequence star with T{sub eff} = 5515 {+-} 124 K. The semi-amplitude K of the RV orbit is 78.7{sup +8.5}{sub -9.5} m s{sup -1}, which yields a planet mass of 0.66 {+-} 0.1 M{sub Jup}. The planet has a radius of 0.96 {+-} 0.06 R{sub Jup} and a mean bulk density of 0.9 {+-} 0.2 g cm{sup -3}. The radius of Kepler-15b is smaller than the majority of transiting planets with similar mass and irradiation level. This suggests that the planet is more enriched in heavy elements than most other transiting giant planets. For Kepler-15b we estimate a heavy element mass of 30-40 M{sub Circled-Plus }.

  9. The detection of Earth-mass planets around active stars. The mass of Kepler-78b

    NASA Astrophysics Data System (ADS)

    Hatzes, A. P.

    2014-08-01

    Kepler-78b is a transiting Earth-mass planet in an 8.5 h orbit discovered by the Kepler Space Mission. We performed an analysis of the published radial velocity measurements for Kepler-78 in order to derive a refined measurement for the planet mass. Kepler-78 is an active star and radial velocity variations due to activity were removed using a floating chunk offset (FCO) method where an orbital solution was made to the data by allowing the velocity offsets of individual nights to vary. We show that if we had no a priori knowledge of the transit period the FCO method, used as a periodogram, would still have detected Kepler-78b in the radial velocity data. It can thus be effective at finding unknown short-period signals in the presence of significant activity noise.Using the FCO method while keeping the ephemeris and orbital phase fixed to the photometric values and using only data from nights where 6-10 measurements were taken results in a K-amplitude of 1.34 ± 0.25 m s-1, a planet mass of 1.31 ± 0.24 M?, and a planet density of ? = 4.5-2.0+2.2 g cm-3. Allowing the orbital phase to be a free parameter reproduces the transit phase to within the uncertainty. The corresponding density implies that Kepler-78b may have a structure that is deficient in iron and is thus more like the Moon. Although the various approaches that were used to filter out the activity of Kepler-78 produce consistent radial velocity amplitudes to within the errors, these are still too large to constrain the structure of this planet. The uncertainty in the mass for Kepler-78b is large enough to encompass models with structures ranging from Mercury-like (iron enriched) to Moon-like (iron deficient). A more accurate K-amplitude as well as a better determination of the planet radius are needed to distinguish between these models.

  10. A Day on Jupiter (Animation)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This 'movie' strings 11 images of Jupiter captured by the New Horizons Long Range Reconnaissance Imager (LORRI) on January 9, 2007, when the spacecraft was about 80 million kilometers (49.6 million miles) from the giant planet. The sequence covers a full 10-hour rotation of Jupiter, during which the moons Ganymede and Io -- as well as the shadows they cast on Jupiter -- move across the camera's field of view.

  11. Small, Numerous and Close-in: The Population of Planets around Low-mass Stars.

    NASA Astrophysics Data System (ADS)

    Mulders, Gijs Dirk; Pascucci, Ilaria; apai, Daniel

    2015-08-01

    The Kepler Space Telescope has monitored stars from spectral type M to A for transiting exoplanets, covering a factor four in planet host star mass. We take advantage of this large coverage in stellar masses to establish what are the key processes in the formation and evolution of planetary systems.We derive planet occurrence rates for a range of orbital periods and planet sizes, taking into account the different observational biases that exist for stars of different mass, size, and luminosity. This uniform approach allows us to compare planet populations directly and identify scaling relations with stellar mass. We identify three trends:First, planets around lower mass stars are found closer to their hosts stars. The inner edges of the planet populations match the inner edges of the gas disks where planets halt their migration. Second, the size of the largest planets decreases with stellar mass, indicating formation in less massive disks. Third, the 3-4 times higher occurrence rate of small (1-3 earth radii) planets around M dwarfs with respect to sunlike stars indicates an increased planet migration efficiency and is inconsistent with in-situ formation models.Our findings demonstrate how exoplanet studies around stars of very different masses can pin down specific physical processes shaping the final architecture of planetary systems. We will conclude by exploring how the yield from the Kepler extended mission -- with a large number of M stars but a different detection bias -- can further our knowledge of planet formation and evolution.References:Mulders et al. 2015Mulders et al. in prep

  12. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    SciTech Connect

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G.

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  13. On the Mass-Period Distributions and Correlations of Extrasolar Planets

    E-print Network

    Ing-Guey Jiang; Li-Chin Yeh; Yen-Chang Chang; Wen-Liang Hung

    2007-09-05

    In addition to fitting the data of 233 extra-solar planets with power laws, we construct a correlated mass-period distribution function of extrasolar planets, as the first time in this field. The algorithm to generate a pair of positively correlated beta-distributed random variables is introduced and used for the construction of correlated distribution functions. We investigate the mass-period correlations of extrasolar planets both in the linear and logarithm spaces, determine the confidence intervals of the correlation coefficients, and confirm that there is a positive mass-period correlation for the extrasolar planets. In addition to the paucity of massive close-in planets, which makes the main contribution on this correlation, there are other fine structures for the data in the mass-period plane.

  14. On the Number of Hot Jupiters Having Extended Non-Spherical Envelopes

    NASA Astrophysics Data System (ADS)

    Bisikalo, D. V.; Kaygorodov, P. V.; Arakcheev, A. S.

    2015-07-01

    A system containing a hot Jupiter and its host star may be considered as a binary system with an extremely low mass ratio. Among 189 hot Jupiters currently known (October 2014), 54 planets have atmospheres exceeding the size of the Roche lobe by ˜3 RJup on average. This degree of overfilling should result in a very high rate of mass loss through the vicinity of the inner Lagrangian point, and should significantly reduce the lifetime of an exoplanet. However, observations to not show this. Previously we proposed a mechanism that explains stable hot Jupiter atmospheres extending far beyond the Roche lobes. By this mechanism, the atmospheres are stabilized by the interaction with the stellar wind. In this case an extended non-spherical long-lived envelope forms around the hot Jupiter. In this work we consider the parameters of a sample of currently known hot Jupiters in order to find objects that may potentially have extended gaseous envelopes.

  15. A limit on the presence of Earth-mass planets around a Sun-like star

    SciTech Connect

    Agol, Eric; Steffen, Jason H.; /Fermilab

    2006-10-01

    We present a combined analysis of all publicly available, visible HST observations of transits of the planet HD 209458b. We derive the times of transit, planet radius, inclination, period, and ephemeris. The transit times are then used to constrain the existence of secondary planets in the system. We show that planets near an Earth mass can be ruled out in low-order mean-motion resonance, while planets less than an Earth mass are ruled out in interior, 2:1 resonance. We also present a combined analysis of the transit times and 68 high precision radial velocity measurements of the system. These results are compared to theoretical predictions for the constraints that can be placed on secondary planets.

  16. Jupiter and Super-Earth embedded in a gaseous disc

    E-print Network

    E. Podlewska; E. Szuszkiewicz

    2007-12-19

    In this paper we investigate the evolution of a pair of interacting planets - a Jupiter mass planet and a Super-Earth with the 5.5 Earth masses - orbiting a Solar type star and embedded in a gaseous protoplanetary disc. We focus on the effects of type I and II orbital migrations, caused by the planet-disc interaction, leading to the Super-Earth capture in first order mean motion resonances by the Jupiter. The stability of the resulting resonant system in which the Super-Earth is on the internal orbit relatively to the Jupiter has been studied numerically by means of full 2D hydrodynamical simulations. Our main motivation is to determine the Super-Earth behaviour in the presence of the gas giant in the system. It has been found that the Jupiter captures the Super-Earth into the interior 3:2 or 4:3 mean motion resonances and the stability of such configurations depends on the initial planet positions and eccentricity evolution. If the initial separation of planet orbits is larger or close to that required for the exact resonance than the final outcome is the migration of the pair of planets with the rate similar to that of the gas giant at least for time of our simulations. Otherwise we observe a scattering of the Super-Earth from the disc. The evolution of planets immersed in the gaseous disc has been compared with their behaviour in the case of the classical three-body problem when the disc is absent.

  17. Jupiter - friend or foe? II: the Centaurs

    NASA Astrophysics Data System (ADS)

    Horner, J.; Jones, B. W.

    2009-04-01

    It has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of minor bodies upon the Earth, and thus enabling the development and evolution of life in a collisional environment which is not overly hostile. In other words, it is thought that, thanks to Jupiter, mass extinctions have been sufficiently infrequent that the biosphere has been able to diversify and prosper. However, in the past, little work has been carried out to examine the validity of this idea. In the second of a series of papers, we examine the degree to which the impact risk resulting from objects on Centaur-like orbits is affected by the presence of a giant planet, in an attempt to fully understand the impact regime under which life on Earth has developed. The Centaurs are a population of ice-rich bodies which move on dynamically unstable orbits in the outer Solar system. The largest Centaurs known are several hundred kilometres in diameter, and it is certain that a great number of kilometre or sub-kilometre sized Centaurs still await discovery. These objects move on orbits which bring them closer to the Sun than Neptune, although they remain beyond the orbit of Jupiter at all times, and have their origins in the vast reservoir of debris known as the Edgeworth-Kuiper belt that extends beyond Neptune. Over time, the giant planets perturb the Centaurs, sending a significant fraction into the inner Solar System where they become visible as short-period comets. In this work, we obtain results which show that the presence of a giant planet can act to significantly change the impact rate of short-period comets on the Earth, and that such planets often actually increase the impact flux greatly over that which would be expected were a giant planet not present.

  18. Securing the Extremely Low-Densities of Low-Mass Planets Characterized by Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.

    2015-12-01

    Transit timing variations (TTVs) provide an excellent tool to characterize the masses and orbits of dozens of small planets, including many at orbital periods beyond the reach of both Doppler surveys and photoevaporation-induced atmospheric loss. Dynamical modeling of these systems has identified low-mass planets with surprisingly large radii and low densities (e.g., Kepler-79d, Jontof-Hutter et al. 2014; Kepler-51, Masuda 2014; Kepler-87c, Ofir et al. 2014). Additional low-density, low-mass planets will likely become public before ESS III (Jontof-Hutter et al. in prep). Collectively, these results suggest that very low density planets with masses of 2-6 MEarth are not uncommon in compact multiple planet systems. Some astronomers have questioned whether there could be an alternative interpretation of the TTV observations. Indeed, extraordinary claims require extraordinary evidence. While the physics of TTVs is rock solid, the statistical analysis of Kepler observations can be challenging, due to the complex interactions between model parameters and high-dimensional parameter spaces that must be explored. We summarize recent advances in computational statistics that enable robust characterization of planetary systems using TTVs. We present updated analyses of a few particularly interesting systems and discuss the implications for the robustness of extremely low densities for low-mass planets. Such planets pose an interesting challenge for planet formation theory and are motivating detailed theoretical studies (e.g., Lee & Chiang 2015 and associated ESS III abstracts).

  19. Mass Estimates of a Giant Planet in a Protoplanetary Disk from the Gap Structures

    NASA Astrophysics Data System (ADS)

    Kanagawa, Kazuhiro D.; Muto, Takayuki; Tanaka, Hidekazu; Tanigawa, Takayuki; Takeuchi, Taku; Tsukagoshi, Takashi; Momose, Munetake

    2015-06-01

    A giant planet embedded in a protoplanetary disk forms a gap. An analytic relationship among the gap depth, planet mass Mp, disk aspect ratio hp, and viscosity ? has been found recently, and the gap depth can be written in terms of a single parameter K={{({{M}p}/{{M}*})}2}hp-5{{? }-1}. We discuss how observed gap features can be used to constrain the disk and/or planet parameters based on the analytic formula for the gap depth. The constraint on the disk aspect ratio is critical in determining the planet mass so the combination of the observations of the temperature and the image can provide a constraint on the planet mass. We apply the formula for the gap depth to observations of HL Tau and HD 169142. In the case of HL Tau, we propose that a planet with ? 0.3 MJ is responsible for the observed gap at 30 AU from the central star based on the estimate that the gap depth is ? 1/3. In the case of HD 169142, the planet mass that causes the gap structure recently found by VLA is ? 0.4{{M}J}. We also argue that the spiral structure, if observed, can be used to estimate the lower limit of the disk aspect ratio and the planet mass.

  20. Towards A Census of Earth-mass Exo-planets with Gravitational Microlensing

    E-print Network

    J. P. Beaulieu; E. Kerins; S. Mao; D. Bennett; A. Cassan; S. Dieters; B. S. Gaudi; A. Gould; V. Batista; R. Bender; S. Brillant; K. Cook; C. Coutures; D. Dominis-Prester; J. Donatowicz; P. Fouqué; E. Grebel; J. Greenhill; D. Heyrovsky; K. Horne; D. Kubas; J. B. Marquette; J. Menzies; N. J. Rattenbury; I. Ribas; K. Sahu; Y. Tsapras; A. Udalski; C. Vinter

    2008-07-31

    Thirteen exo-planets have been discovered using the gravitational microlensing technique (out of which 7 have been published). These planets already demonstrate that super-Earths (with mass up to ~10 Earth masses) beyond the snow line are common and multiple planet systems are not rare. In this White Paper we introduce the basic concepts of the gravitational microlensing technique, summarise the current mode of discovery and outline future steps towards a complete census of planets including Earth-mass planets. In the near-term (over the next 5 years) we advocate a strategy of automated follow-up with existing and upgraded telescopes which will significantly increase the current planet detection efficiency. In the medium 5-10 year term, we envision an international network of wide-field 2m class telescopes to discover Earth-mass and free-floating exo-planets. In the long (10-15 year) term, we strongly advocate a space microlensing telescope which, when combined with Kepler, will provide a complete census of planets down to Earth mass at almost all separations. Such a survey could be undertaken as a science programme on Euclid, a dark energy probe with a wide-field imager which has been proposed to ESA's Cosmic Vision Programme.

  1. The Pan-Pacific Planet Search. IV. Two super-Jupiters in a 3:5 resonance orbiting the giant star HD33844

    E-print Network

    Wittenmyer, Robert A; Butler, R P; Horner, Jonathan; Wang, Liang; Robertson, Paul; Jones, M I; Jenkins, J S; Brahm, R; Tinney, C G; Mengel, M W; Clark, J

    2015-01-01

    We report the discovery of two giant planets orbiting the K giant HD 33844 based on radial velocity data from three independent campaigns. The planets move on nearly circular orbits with semimajor axes $a_b=1.60\\pm$0.02 AU and $a_c=2.24\\pm$0.05 AU, and have minimum masses (m sin $i$) of $M_b=1.96\\pm$0.12 Mjup and $M_c=1.76\\pm$0.18 Mjup. Detailed N-body dynamical simulations show that the two planets remain on stable orbits for more than $10^6$ years for low eccentricities, and are most likely trapped in a mutual 3:5 mean-motion resonance.

  2. PLANET HUNTERS. VII. DISCOVERY OF A NEW LOW-MASS, LOW-DENSITY PLANET (PH3 C) ORBITING KEPLER-289 WITH MASS MEASUREMENTS OF TWO ADDITIONAL PLANETS (PH3 B AND D)

    E-print Network

    Schmitt, Joseph R.

    We report the discovery of one newly confirmed planet (P = 66.06 days, R [subscript P] = 2.68 ± 0.17 R [subscript ?]) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R ...

  3. Friends of hot Jupiters. I. A radial velocity search for massive, long-period companions to close-in gas giant planets

    SciTech Connect

    Knutson, Heather A.; Ngo, Henry; Johnson, John Asher; Fulton, Benjamin J.; Howard, Andrew W.; Montet, Benjamin T.; Kao, Melodie; Hinkley, Sasha; Morton, Timothy D.; Muirhead, Philip S.; Crepp, Justin R.; Bakos, Gaspar Á.; Batygin, Konstantin

    2014-04-20

    In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 planets obtained using the Keck HIRES instrument, and find statistically significant accelerations in fifteen systems. Six of these systems have no previously reported accelerations in the published literature: HAT-P-10, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 adaptive optics (AO) imaging data to place constraints on the allowed masses and orbital periods of the companions responsible for the detected accelerations. The estimated masses of the companions range between 1-500 M {sub Jup}, with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the transiting planets in these systems, making them candidates for influencing the orbital evolution of the inner gas giant. We estimate a total occurrence rate of 51% ± 10% for companions with masses between 1-13 M {sub Jup} and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions to transiting planets with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the planets included in our survey.

  4. Friends of Hot Jupiters. I. A Radial Velocity Search for Massive, Long-period Companions to Close-in Gas Giant Planets

    NASA Astrophysics Data System (ADS)

    Knutson, Heather A.; Fulton, Benjamin J.; Montet, Benjamin T.; Kao, Melodie; Ngo, Henry; Howard, Andrew W.; Crepp, Justin R.; Hinkley, Sasha; Bakos, Gaspar Á.; Batygin, Konstantin; Johnson, John Asher; Morton, Timothy D.; Muirhead, Philip S.

    2014-04-01

    In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 planets obtained using the Keck HIRES instrument, and find statistically significant accelerations in fifteen systems. Six of these systems have no previously reported accelerations in the published literature: HAT-P-10, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 adaptive optics (AO) imaging data to place constraints on the allowed masses and orbital periods of the companions responsible for the detected accelerations. The estimated masses of the companions range between 1-500 M Jup, with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the transiting planets in these systems, making them candidates for influencing the orbital evolution of the inner gas giant. We estimate a total occurrence rate of 51% ± 10% for companions with masses between 1-13 M Jup and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions to transiting planets with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the planets included in our survey.

  5. Low-Density Low-Mass Planets Forma4on and Structure of Low-Density Exo-Neptunes

    E-print Network

    Johnson, Robert E.

    -Density Exo-Neptunes Leslie A. Rogers, Peter Bodenheimer, Jack J. Lissauer, & Sara masses of Neptune- size (2-6 R) planets? Planets with gas layers can get larger: Neptune-size Kepler planet candidates could have low mass (a few Earth masses

  6. Jupiter Polar Winds Movie

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Bands of eastward and westward winds on Jupiter appear as concentric rotating circles in this movie composed of Cassini spacecraft images that have been re-projected as if the viewer were looking down at Jupiter's north pole and the planet were flattened.

    The sequence covers 70 days, from October 1 to December 9, 2000. Cassini's narrow-angle camera captured the images of Jupiter's atmosphere in the near-infrared region of the spectrum.

    What is surprising in this view is the coherent nature of the high-latitude flows, despite the very chaotic, mottled and non-banded appearance of the planet's polar regions. This is the first extended movie sequence to show the coherence and longevity of winds near the pole and the features blown around the planet by them.

    There are thousands of spots, each an active storm similar to the size to the largest of storms on Earth. Large terrestrial storms usually last only a week before they dissolve and are replaced by other storms. But many of the Jovian storms seen here, while occasionally changing latitude or merging with each other, persist for the entire 70 days. Until now, the lifetime of the high-latitude features was unknown. Their longevity is a mystery of Jovian weather.

    Cassini collected images of Jupiter for months before and after it passed the planet on December 30, 2000. Six or more images of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire sequence was repeated generally every other Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours.

    The images used for the movie shown here were taken every 20 hours through a filter centered at a wavelength of 756 nanometers, where there are almost no absorptions in the planet's atmosphere. The images covering each rotation were mosaiced together to form a cylindrical map extending from 75 degrees north to 75 degrees south in latitude and covering 360 degrees in longitude. The movie consists of 84 such maps, spanning 70 Earth days in time or 168 Jupiter rotations.

    Transforming the cylindrical maps into polar stereographic projections produces a movie of what Jupiter would look like if viewed from the pole. Jupiter's alternating eastward and westward jet streams flow in concentric rings around the pole, with equatorial motions visible in the corners. The dark features flowing counterclockwise near the equator are'hot spots' where cloud cover is relatively thin.

    The high-latitude movements call into question one notion concerning wind circulation on Jupiter. The model in question suggests that Jupiter'a alternating bands of east-west winds are the exposed edges of deeper rotating cylinders that extend north-south through the planet. However, the east-west winds that the movie shows in polar regions don't fit that model. The cylinders whose edges would form those bands would have to go through the innermost portion of the planet, where the cylinders' different rotations could not be maintained. Jupiter's wind pattern may involve a mix of rotation-on-cylinders near the equator and some other circulation mechanism near the poles.

    For more information, see the Cassini Project home page, http://www.jpl.nasa.gov/cassini/ and the Cassini Imaging Team home page, http://ciclops.lpl.arizona.edu/ciclops/ .

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  7. Jupiter's Role in Sculpting the Early Solar System

    NASA Astrophysics Data System (ADS)

    Naoz, Smadar

    2015-03-01

    Recent observations made by the Kepler space mission, combined with statistical analysis of existing ground and space-based data, have shown that planets somewhat bigger than the Earth - but substantially smaller than Jupiter - ;are extremely common in our Galaxy (1-4). These systems are typically found to be tightly packed, nearly coplanar, and have nearly circular orbits. Furthermore, these planets tend to have very short-period orbits, ranging from days to months. In contrast, our innermost planet, Mercury, orbits the Sun once every 88 d. Thus, taken at face value, these observations imply that the architecture of our Solar System is unique compared with the galactic population. In other words, why are there no short-period planets in our Solar System? In PNAS, Batygin and Laughlin (5) demonstrate that Jupiter is to blame. In particular, Jupiter's inward-followed-by-outward migration during the Solar System's early evolution could have driven a collisional cascade that would grind planetesimals to smaller size. Gas drag, which dominates these small planetesimals, may then have driven preexisting short-period planets into the Sun. Thus, Batygin and Laughlin (5) suggest that the terrestrial planets in our Solar System are in fact "second-generation planets," which formed after the first short-period planets were destroyed, in mass-dispersed, gas-depleted conditions (see Fig. 1 for the description of the scenario). The developed model suggests that systems with short-period Earth and super-Earth planets are anticorrelated with the existence of giant planets within the same system.

  8. Combining Transit and Radial Velocity Data to Infer the Planet Mass-Radius-Flux Distribution

    NASA Astrophysics Data System (ADS)

    Rogers, Leslie Anne

    2015-08-01

    The Kepler Mission, combined with ground based radial velocity (RV) follow-up, has revolutionized the observational constraints on sub-Neptune-size planet compositions. Kepler’s unprecedentedly large and homogeneous samples of planets with both mass and radius constraints open the possibility of statistical studies of the underlying planet composition distribution. This presentation will describe the application of hierarchical Bayesian models to constrain the underlying planet composition distribution from a sample of noisy mass-radius measurements. This approach represents a promising avenue toward a quantitative measurement of the amount of physical scatter in small planet compositions, the identification of planet sub-populations that may be tied to distinct formation pathways, and empirical constraints on the dominant compositional trends in the planet sample. Both the transit and radial velocity techniques are subject to selection effects, and approaches to mitigate the resulting biases will be addressed. In addition to distilling composition-distribution insights from the current sample of Kepler planets with RV masses, this framework may be used to optimize the target selection for future transiting planet RV follow-up surveys.

  9. The effect of stellar evolution on migrating warm jupiters

    NASA Astrophysics Data System (ADS)

    Frewen, S. F. N.; Hansen, B. M. S.

    2016-01-01

    Warm jupiters are an unexpected population of extrasolar planets that are too near to their host to have formed in situ, but distant enough to retain a significant eccentricity in the face of tidal damping. These planets are curiously absent around stars larger than two solar radii. We hypothesize that the warm jupiters are migrating due to Kozai-Lidov oscillations, which lead to transient episodes of high eccentricity and a consequent tidal decay. As their host evolves, such planets would be rapidly dragged in or engulfed at minimum periapse, leading to a dramatic depletion of this population with increasing stellar radius, as is observed. Using numerical simulations, we determine the relationship between periapse distance and orbital migration rate for planets 0.1-10 Jupiter masses and with orbital periods between 10 and 100 d. We find that Kozai-Lidov oscillations effectively result in planetary removal early in the evolution of the host star, possibly accounting for the observed deficit. While the observed eccentricity distribution is inconsistent with the simulated distribution for an oscillating and migrating warm jupiter population, observational biases may explain the discrepancy.

  10. EVIDENCE FROM THE ASTEROID BELT FOR A VIOLENT PAST EVOLUTION OF JUPITER'S ORBIT

    SciTech Connect

    Morbidelli, Alessandro; Brasser, Ramon; Gomes, Rodney; Levison, Harold F.; Tsiganis, Kleomenis

    2010-11-15

    We use the current orbital structure of large (>50 km) asteroids in the main asteroid belt to constrain the evolution of the giant planets when they migrated from their primordial orbits to their current ones. Minton and Malhotra showed that the orbital distribution of large asteroids in the main belt can be reproduced by an exponentially decaying migration of the giant planets on a timescale of {tau} {approx} 0.5 Myr. However, self-consistent numerical simulations show that the planetesimal-driven migration of the giant planets is inconsistent with an exponential change in their semi-major axes on such a short timescale. In fact, the typical timescale is {tau} {>=} 5 Myr. When giant planet migration on this timescale is applied to the asteroid belt, the resulting orbital distribution is incompatible with the observed one. However, the planet migration can be significantly sped up by planet-planet encounters. Consider an evolution where both Jupiter and Saturn have close encounters with a Neptune-mass planet (presumably Uranus or Neptune itself) and where this third planet, after being scattered inward by Saturn, is scattered outward by Jupiter. This scenario leads to a very rapid increase in the orbital separation between Jupiter and Saturn which we show here to have only mild effects on the structure of the asteroid belt. This type of evolution is called a 'jumping-Jupiter' case. Our results suggest that the total mass and dynamical excitation of the asteroid belt before migration were comparable to those currently observed. Moreover, they imply that, before migration, the orbits of Jupiter and Saturn were much less eccentric than their current ones.

  11. CMB. A spacecraft of mass m is to be sent from the Earth to Jupiter. It is decided to use a Hohmann-ellipse transfer orbit which is tangential to

    E-print Network

    Ha, Taekjip

    CMB. A spacecraft of mass m is to be sent from the Earth to Jupiter. It is decided to use a Hohmann, and to the orbit (also assumed circular) of Jupiter at r = R2. [There is more than one way of solving this problem Earth Jupiter a) Find the orbital velocities v1 and v2 of the Earth and Jupiter. Your answer should

  12. HABITABILITY OF EARTH-MASS PLANETS AND MOONS IN THE KEPLER-16 SYSTEM

    SciTech Connect

    Quarles, B.; Musielak, Z. E.; Cuntz, M. E-mail: zmusielak@uta.edu

    2012-05-01

    We demonstrate that habitable Earth-mass planets and moons can exist in the Kepler-16 system, known to host a Saturn-mass planet around a stellar binary, by investigating their orbital stability in the standard and extended habitable zone (HZ). We find that Earth-mass planets in satellite-like (S-type) orbits are possible within the standard HZ in direct vicinity of Kepler-16b, thus constituting habitable exomoons. However, Earth-mass planets cannot exist in planetary-like (P-type) orbits around the two stellar components within the standard HZ. Yet, P-type Earth-mass planets can exist superior to the Saturnian planet in the extended HZ pertaining to considerably enhanced back-warming in the planetary atmosphere if facilitated. We briefly discuss the potential detectability of such habitable Earth-mass moons and planets positioned in satellite and planetary orbits, respectively. The range of inferior and superior P-type orbits in the HZ is between 0.657-0.71 AU and 0.95-1.02 AU, respectively.

  13. mass function of the brown dwarfs/giant planets, we need to conduct more compre-

    E-print Network

    Zreda, Marek

    mass function of the brown dwarfs/giant planets, we need to conduct more compre- hensive surveys the very young brown dwarfs at several hundred as- tronomical units from their companions de- scribed in this paper and the close (0.5 to 10 astronomical units) extrasolar giant planets and brown dwarfs around

  14. ORBITAL MIGRATION OF LOW-MASS PLANETS IN EVOLUTIONARY RADIATIVE MODELS: AVOIDING CATASTROPHIC INFALL

    SciTech Connect

    Lyra, Wladimir; Mac Low, Mordecai-Mark; Paardekooper, Sijme-Jan E-mail: mordecai@amnh.or

    2010-06-01

    Outward migration of low-mass planets has recently been shown to be a possibility in non-barotropic disks. We examine the consequences of this result in evolutionary models of protoplanetary disks. Planet migration occurs toward equilibrium radii with zero torque. These radii themselves migrate inwards because of viscous accretion and photoevaporation. We show that as the surface density and temperature fall the planet orbital migration and disk depletion timescales eventually become comparable, with the precise timing depending on the mass of the planet. When this occurs, the planet decouples from the equilibrium radius. At this time, however, the gas surface density is already too low to drive substantial further migration. A higher mass planet, of 10 M {sub +}, can open a gap during the late evolution of the disk, and stops migrating. Low-mass planets, with 1 or 0.1 M {sub +}, released beyond 1 AU in our models avoid migrating into the star. Our results provide support for the reduced migration rates adopted in recent planet population synthesis models.

  15. Formation of the giant planets

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2006-01-01

    The observed properties of giant planets, models of their evolution and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our Solar System contain considerable quantities of hydrogen and helium, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our Solar System, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory .experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions planets with small cores/total heavy element abundances can accrete gaseous envelopes within the lifetimes of gaseous protoplanetary disks.

  16. The Search for other Earths: limits on the giant planet orbits that allow habitable terrestrial planets to form

    E-print Network

    Sean N. Raymond

    2006-05-04

    Gas giant planets are far easier than terrestrial planets to detect around other stars, and are thought to form much more quickly than terrestrial planets. Thus, in systems with giant planets, the late stages of terrestrial planet formation are strongly affected by the giant planets' dynamical presence. Observations of giant planet orbits may therefore constrain the systems that can harbor potentially habitable, Earth-like planets. We present results of 460 N-body simulations of terrestrial accretion from a disk of Moon- to Mars-sized planetary embryos. We systematically vary the orbital semimajor axis of a Jupiter-mass giant planet between 1.6 and 6 AU, and eccentricity between 0 and 0.4. We find that for Sun-like stars, giant planets inside roughly 2.5 AU inhibit the growth of 0.3 Earth-mass planets in the habitable zone. If planets accrete water from volatile-rich embryos past 2-2.5 AU, then water-rich habitable planets can only form in systems with giant planets beyond 3.5 AU. Giant planets with significant orbital eccentricities inhibit both accretion and water delivery. The majority of the current sample of extra-solar giant planets appears unlikely to form habitable planets.

  17. Planet hunters. VII. Discovery of a new low-mass, low-density planet (PH3 C) orbiting Kepler-289 with mass measurements of two additional planets (PH3 B and D)

    SciTech Connect

    Schmitt, Joseph R.; Fischer, Debra A.; Wang, Ji; Margossian, Charles; Brewer, John M.; Giguere, Matthew J.; Agol, Eric; Deck, Katherine M.; Rogers, Leslie A.; Gazak, J. Zachary; Holman, Matthew J.; Jek, Kian J.; Omohundro, Mark R.; Winarski, Troy; Lintott, Chris; Simpson, Robert; Lynn, Stuart; Parrish, Michael; Schawinski, Kevin; Schwamb, Megan E.; and others

    2014-11-10

    We report the discovery of one newly confirmed planet (P = 66.06 days, R {sub P} = 2.68 ± 0.17 R {sub ?}) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R {sub P} = 2.15 ± 0.10 R {sub ?}) and Kepler-289-c (P = 125.85 days, R {sub P} = 11.59 ± 0.10 R {sub ?}), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a 1:2:4 Laplace resonance. The outer planet has very deep (?1.3%), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young (?1 Gyr as determined by isochrones and gyrochronology), Sun-like star with M {sub *} = 1.08 ± 0.02 M {sub ?}, R {sub *} = 1.00 ± 0.02 R {sub ?}, and T {sub eff} = 5990 ± 38 K. The middle planet's large TTV amplitude (?5 hr) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allows us to break the mass-eccentricity degeneracy and uniquely determine the masses of the inner, middle, and outer planets to be M = 7.3 ± 6.8 M {sub ?}, 4.0 ± 0.9M {sub ?}, and M = 132 ± 17 M {sub ?}, which we designate PH3 b, c, and d, respectively. Furthermore, the middle planet, PH3 c, has a relatively low density, ? = 1.2 ± 0.3 g cm{sup –3} for a planet of its mass, requiring a substantial H/He atmosphere of 2.1{sub ?0.3}{sup +0.8}% by mass, and joins a growing population of low-mass, low-density planets.

  18. Atmospheric escape by magnetically driven wind from gaseous planets

    SciTech Connect

    Tanaka, Yuki A.; Suzuki, Takeru K.; Inutsuka, Shu-ichiro

    2014-09-01

    We calculate the mass loss driven by magnetohydrodynamic (MHD) waves from hot Jupiters by using MHD simulations in one-dimensional flux tubes. If a gaseous planet has a magnetic field, MHD waves are excited by turbulence at the surface, dissipate in the upper atmosphere, and drive gas outflows. Our calculation shows that mass-loss rates are comparable to the observed mass-loss rates of hot Jupiters; therefore, it is suggested that gas flow driven by MHD waves can play an important role in the mass loss from gaseous planets. The mass-loss rate varies dramatically with the radius and mass of a planet: a gaseous planet with a small mass but an inflated radius produces a very large mass-loss rate. We also derive an analytical expression for the dependence of mass-loss rate on planet radius and mass that is in good agreement with the numerical calculation. The mass-loss rate also depends on the amplitude of the velocity dispersion at the surface of a planet. Thus, we expect to infer the condition of the surface and the internal structure of a gaseous planet from future observations of mass-loss rate from various exoplanets.

  19. A closely packed system of low-mass, low-density planets transiting Kepler-11.

    PubMed

    Lissauer, Jack J; Fabrycky, Daniel C; Ford, Eric B; Borucki, William J; Fressin, Francois; Marcy, Geoffrey W; Orosz, Jerome A; Rowe, Jason F; Torres, Guillermo; Welsh, William F; Batalha, Natalie M; Bryson, Stephen T; Buchhave, Lars A; Caldwell, Douglas A; Carter, Joshua A; Charbonneau, David; Christiansen, Jessie L; Cochran, William D; Desert, Jean-Michel; Dunham, Edward W; Fanelli, Michael N; Fortney, Jonathan J; Gautier, Thomas N; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer R; Holman, Matthew J; Koch, David G; Latham, David W; Lopez, Eric; McCauliff, Sean; Miller, Neil; Morehead, Robert C; Quintana, Elisa V; Ragozzine, Darin; Sasselov, Dimitar; Short, Donald R; Steffen, Jason H

    2011-02-01

    When an extrasolar planet passes in front of (transits) its star, its radius can be measured from the decrease in starlight and its orbital period from the time between transits. Multiple planets transiting the same star reveal much more: period ratios determine stability and dynamics, mutual gravitational interactions reflect planet masses and orbital shapes, and the fraction of transiting planets observed as multiples has implications for the planarity of planetary systems. But few stars have more than one known transiting planet, and none has more than three. Here we report Kepler spacecraft observations of a single Sun-like star, which we call Kepler-11, that reveal six transiting planets, five with orbital periods between 10 and 47?days and a sixth planet with a longer period. The five inner planets are among the smallest for which mass and size have both been measured, and these measurements imply substantial envelopes of light gases. The degree of coplanarity and proximity of the planetary orbits imply energy dissipation near the end of planet formation. PMID:21293371

  20. Galilean Moons, Kepler's Third Law, and the Mass of Jupiter

    ERIC Educational Resources Information Center

    Bates, Alan

    2013-01-01

    Simulations of physical systems are widely available online, with no cost, and are ready to be used in our classrooms. Such simulations offer an accessible tool that can be used for a range of interactive learning activities. The Jovian Moons Apple allows the user to track the position of Jupiter's four Galilean moons with a variety of…

  1. Taxonomy of the extrasolar planet.

    PubMed

    Plávalová, Eva

    2012-04-01

    When a star is described as a spectral class G2V, we know that the star is similar to our Sun. We know its approximate mass, temperature, age, and size. When working with an extrasolar planet database, it is very useful to have a taxonomy scale (classification) such as, for example, the Harvard classification for stars. The taxonomy has to be easily interpreted and present the most relevant information about extrasolar planets. I propose an extrasolar planet taxonomy scale with four parameters. The first parameter concerns the mass of an extrasolar planet in the form of units of the mass of other known planets, where M represents the mass of Mercury, E that of Earth, N Neptune, and J Jupiter. The second parameter is the planet's distance from its parent star (semimajor axis) described in a logarithm with base 10. The third parameter is the mean Dyson temperature of the extrasolar planet, for which I established four main temperature classes: F represents the Freezing class, W the Water class, G the Gaseous class, and R the Roasters class. I devised one additional class, however: P, the Pulsar class, which concerns extrasolar planets orbiting pulsar stars. The fourth parameter is eccentricity. If the attributes of the surface of the extrasolar planet are known, we are able to establish this additional parameter where t represents a terrestrial planet, g a gaseous planet, and i an ice planet. According to this taxonomy scale, for example, Earth is 1E0W0t, Neptune is 1N1.5F0i, and extrasolar planet 55 Cnc e is 9E-1.8R1. PMID:22506608

  2. Reevaluating the feasibility of ground-based Earth-mass microlensing planet detections

    SciTech Connect

    Jung, Youn Kil; Park, Hyuk; Han, Cheongho; Hwang, Kyu-Ha; Shin, In-Gu; Choi, Joon-Young

    2014-05-10

    An important strength of the microlensing method to detect extrasolar planets is its high sensitivity to low-mass planets. However, many believe that microlensing detections of Earth-mass planets from ground-based observation would be difficult because of limits set by finite-source effects. This view comes from the previous estimation of planet detection probability based on the fractional deviation of planetary signals; however, a proper probability estimation is required when considering the source brightness, which is directly related to the photometric precision. In this paper, we reevaluate the feasibility of low-mass planet detections by considering photometric precision for different populations of source stars. From this, we find that the contribution of improved photometric precision to the planetary signal of a giant-source event is large enough to compensate for the decrease in magnification excess caused by finite-source effects. As a result, we conclude that giant-source events are suitable targets for Earth-mass planet detections with significantly higher detection probability than events involved with source stars of smaller radii, and we predict that Earth-mass planets could be detected by prospective high-cadence surveys.

  3. Microlensing Sensitivity to Earth-mass Planets in the Habitable Zone

    E-print Network

    Byeong-Gon Park; Young-Beom Jeon; Chung-Uk Lee; Cheongho Han

    2006-01-31

    Microlensing is one of the most powerful methods that can detect extrasolar planets and a future space-based survey with a high monitoring frequency is proposed to detect a large sample of Earth-mass planets. In this paper, we examine the sensitivity of the future microlensing survey to Earth-mass planets located in the habitable zone. For this, we estimate the fraction of Earth-mass planets that will be located in the habitable zone of their parent stars by carrying out detailed simulation of microlensing events based on standard models of the physical and dynamic distributions and the mass function of Galactic matter. From this investigation, we find that among the total detectable Earth-mass planets from the survey, those located in the habitable zone would comprise less than 1% even under a less-conservative definition of the habitable zone. We find the main reason for the low sensitivity is that the projected star-planet separation at which the microlensing planet detection efficiency becomes maximum (lensing zone) is in most cases substantially larger than the median value of the habitable zone. We find that the ratio of the median radius of the habitable zone to the mean radius of the lensing zone is roughly expressed as $d_{\\rm HZ}/r_{\\rm E}\\sim 0.2(m/0.5 M_\\odot)^{1/2}$.

  4. Search for Low-Mass Planets Around Late-M Dwarfs Using IRD

    NASA Astrophysics Data System (ADS)

    Omiya, Masashi; Sato, Bun'ei; Harakawa, Hiroki; Kuzuhara, Masayuki; Hirano, Teruyuki; Narita, Norio

    2014-04-01

    We have a plan to conduct a Doppler planet search for low-mass planets around nearby middle-to-late M dwarfs using IRD. IRD is the near-infrared high-precision radial velocity instrument for the Subaru 8.2-m telescope. We expect to achieve the accuracy of the radial velocity measurements of 1 m/s using IRD with a frequency comb as a wavelengh calibrator. Thus, we would detect super-Earths in habitable zone and low-mass rocky planets in close-in orbits around late-M dwarfs. In this survey, we aim to understand and discuss statistical properties of low-mass planets around low-mass M dwarfs compared with those derived from theoretical simulations.

  5. Planet traps and planetary cores: origins of the planet-metallicity correlation

    SciTech Connect

    Hasegawa, Yasuhiro; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2014-10-10

    Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ? 1 AU, and the low-mass planets. We show using a statistical approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = –0.2 to –0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M {sub c,} {sub crit}) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > –0.6, our models predict that the most likely value of the 'mean' critical core mass of Jovian planets is (M {sub c,} {sub crit}) ? 5 M {sub ?} rather than 10 M {sub ?}. This implies that grain opacities in accreting envelopes should be reduced in order to lower M {sub c,} {sub crit}.

  6. Planet Traps and Planetary Cores: Origins of the Planet-Metallicity Correlation

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yasuhiro; Pudritz, Ralph E.

    2014-10-01

    Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ~= 1 AU, and the low-mass planets. We show using a statistical approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = -0.2 to -0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M c, crit) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > -0.6, our models predict that the most likely value of the "mean" critical core mass of Jovian planets is langM c, critrang ~= 5 M ? rather than 10 M ?. This implies that grain opacities in accreting envelopes should be reduced in order to lower M c, crit.

  7. Formation of Misaligned Hot Jupiters: Star-Disk-Binary Interaction, Spin-Orbit Coupling and Chaos

    NASA Astrophysics Data System (ADS)

    Lai, Dong

    2015-08-01

    Many hot Jupiter systems are found to have highly misaligned orbital axes relative to the stellar spin axes. The formation mecahnisms of these misaligned hot Jupiters remain uncertain. I will discuss (1) the possibility of primordial misalignment in proptoplanetary disks due to star-disk-binary resonant interactions, and (2) chaotic evolution of stellar spin as a giant planet undergoes high-eccetricty, Lidov-Kozai migration. The implications for the observation of misaligned planets will also be discussed, particularly the dependence of hot Jupiter formation on the stellar rotation history and the planet mass.(1) Lai,D. 2014 MNRAS, 440, 3532(2) Storch, N., Anderson, K.R., Lai, D. 2014, Science, 345, 1317(3) Srorch, N., Lai, D. 2015, MNRAS, 448, 1821(4) Anderson, K.R., Storch, N., Lai, D. 2015, MNRAS, submitted

  8. The Jupiter Twin HD 154345b

    NASA Astrophysics Data System (ADS)

    Wright, J. T.; Marcy, G. W.; Butler, R. P.; Vogt, S. S.; Henry, G. W.; Isaacson, H.; Howard, A. W.

    2008-08-01

    We announce the discovery of a twin of Jupiter orbiting the slightly metal-poor ([Fe/H]=-0.1) nearby (d=18 pc) G8 dwarf HD 154345. This planet has a minimum mass of 0.95 MJup and a 9.2 year, circular orbit with radius 4.2 AU. There is currently little or no evidence for other planets in the system, but smaller or exterior planets cannot yet be ruled out. We also detect a ~ 9 year activity cycle in this star photometrically and in chromospheric emission. We rule out activity cycles as the source of the radial velocity variations by comparison with other cycling late G dwarfs. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. The Keck Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  9. A Massive Core in Jupiter Predicted From First-Principles Simulations

    E-print Network

    B. Militzer; W. B. Hubbard; J. Vorberger; I. Tamblyn; S. A. Bonev

    2008-07-26

    Hydrogen-helium mixtures at conditions of Jupiter's interior are studied with first-principles computer simulations. The resulting equation of state (EOS) implies that Jupiter possesses a central core of 14-18 Earth masses of heavier elements, a result that supports core accretion as standard model for the formation of hydrogen-rich giant planets. Our nominal model has about 2 Earth masses of planetary ices in the H-He-rich mantle, a result that is, within modeling errors, consistent with abundances measured by the 1995 Galileo Entry Probe mission (equivalent to about 5 Earth masses of planetary ices when extrapolated to the mantle), suggesting that the composition found by the probe may be representative of the entire planet. Interior models derived from this first-principles EOS do not give a match to Jupiter's gravity moment J4 unless one invokes interior differential rotation, implying that jovian interior dynamics has an observable effect on the measured gravity field.

  10. Kepler’s Low-Mass, Low Density Planets Characterized via Transit Timing

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Ford, Eric B.; Lissauer, Jack; Rowe, Jason; Fabrycky, Daniel

    2015-08-01

    The Kepler mission has revealed an abundance of planets in a regime of mass and size that is absent from the Solar System. This includes systems of high multiplicity within 1 AU, where low-mass volatile-rich planets have been observed in compact orbital configurations, as have smaller, rocky planets. The existing sample of characterized planets on the mass-radius diagram shows no abrupt transition from rocky planets to those that must be volatile-rich, but characteristic trends are beginning to emerge. More precise characterizations of planets by mass, radius, and incident flux are revealing fundamental properties of a common class of exoplanets.There is a small sample of low mass exoplanets with known masses and radii, whose radii are known from transit depths, and whose masses are determined from radial velocity spectroscopy (RV). In the super-Earth mass range, detectability limits this sample to planets that have short orbital periods, and high incident fluxes.In the absence of mass determinations via RV observations, transit timing variations (TTVs) offer a chance to probe perturbations between planets that pass close to one another or are near resonance, and hence dynamical fits to observed transit times can be used to measure planetary masses and orbital parameters. Such modeling with Kepler data probes planetary masses over orbital periods ranging from ~5-200 days, complementing the sample of RV detections, but also with some overlap.In addition, dynamical fits to observed TTVs can tightly constrain the orbital eccentricity vectors in select cases, which can, alongside the transit light curve, tightly constrain the density and radius of the host star, and hence reduce the uncertainty on planetary radius.TTV studies have revealed a class of low-mass, low-density objects with a substantial mass fraction in the form of a voluminous H-rich atmosphere. We will present new precise planetary mass characterizations from TTVs. We find that super-Earth mass planets characterized by TTV are remarkably diverse in bulk density, and can range from super-Earth to sub-Saturn size.

  11. The Internal Structural Adjustment due to Tidal Heating of Short-Period Inflated Giant Planets

    E-print Network

    Pin-Gao Gu; Peter H. Bodenheimer; Douglas N. C. Lin

    2004-03-03

    Several short-period Jupiter-mass planets have been discovered around nearby solar-type stars. During the circularization of their orbits, the dissipation of tidal disturbance by their host stars heats the interior and inflates the sizes of these planets. Based on a series of internal structure calculations for giant planets, we examine the physical processes which determine their luminosity-radius relation. In order for young or intensely heated gas giant planets to attain quasi-hydrostatic equilibria, with sizes comparable to or larger than two Jupiter radii, their interiors must have sufficiently high temperature and low density such that degeneracy effects are relatively weak compared to those in a mature and compact Jupiter. Consequently, the polytropic index monotonically increases whereas the central temperature increases and then decreases with the planets' size. These effects, along with a temperature-sensitive opacity for the radiative surface layers of giant planets, cause the power index of the luminosity's dependence on radius to decrease with increasing radius. For planets larger than twice Jupiter's radius, this index is sufficiently small that they become unstable to tidal inflation. We make comparisons between cases of uniform heating and cases in which the heating is concentrated in various locations within the giant planet. Based on these results we suggest that accurate measurement of the sizes of close-in young Jupiters can be used to probe their internal structure under the influence of tidal heating.

  12. Shaping of the Inner Solar System by the Gas-Driven Migration of Jupiter

    NASA Astrophysics Data System (ADS)

    Walsh, Kevin J.; Morbidelli, Alessando; Raymond, Sean N.; O'Brien, David P.; Mandell, Avi M.

    2014-04-01

    A persistent difficulty in terrestrial planet formation models is creating Mars analogs with the appropriate mass: Mars is typically an order of magnitude too large in simulations. Some recent work found that a small Mars can be created if the planetesimal disk from which the planets form has an outermost edge at 1.0 AU. However, that work and no previous work could produce a truncation of the planetesimal disk while also explaining the mass and structure of the asteroid belt. We show that gas-driven migration of Jupiter inward to 1.5 AU, before its subsequent outward migration, can truncate the disk and repopulate the asteroid belt. This dramatic migration history of Jupiter suggests that the dynamical behavior of our giant planets was more similar to that inferred for extra-solar planets than previously thought, as both have been characterised by substantial radial migration.

  13. Stability of Earth-mass Planets in the Kepler-68 System

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.

    2015-11-01

    A key component of characterizing multi-planet exosystems is testing the orbital stability based on the observed properties. Such characterization not only tests the validity of how observations are interpreted but can also place additional constraints upon the properties of the detected planets. The Kepler mission has identified hundreds of multi-planet systems but there are a few that have additional non-transiting planets and also have well characterized host stars. Kepler-68 is one such system for which we are able to provide a detailed study of the orbital dynamics. We use the stellar parameters to calculate the extent of the habitable zone (HZ) for this system, showing that the outer planet lies within that region. We use N-body integrations to study the orbital stability of the system, in particular placing an orbital inclination constraint on the outer planet of i > 5°. Finally, we present the results of an exhaustive stability simulation that investigates possible locations of stable orbits for an Earth-mass planet. We show that there are several islands of stability within the HZ that could harbor such a planet, most particularly at the 2:3 mean motion resonance with the outer planet.

  14. A planet in a polar orbit of 1.4 solar-mass star

    NASA Astrophysics Data System (ADS)

    Guenther, E. W.; Cusano, F.; Deeg, H.; Gandolfi, D.; Geier, S.; Grziwa, S.; Heber, U.; Tal-Or, L.; Sebastian, D.; Rodler, F.

    2015-09-01

    Although more than a thousand transiting extrasolar planets have been discovered, only very few of them orbit stars that are more massive than the Sun. The discovery of such planets is interesting, because they have formed in disks that are more massive but had a shorter life time than those of solar-like stars. Studies of planets more massive than the Sun thus tell us how the properties of the proto-planetary disks effect the formation of planets. Another aspect that makes these planets interesting is that they have kept their original orbital inclinations. By studying them we can thus find out whether the orbital axes planets are initially aligned to the stars rotational axes, or not. Here we report on the discovery of a planet of a 1.4 solar-mass star with a period of 5.6 days in a polar orbit made by CoRoT. This new planet thus is one of the few known close-in planets orbiting a star that is substantially more massive than the Sun.

  15. Water Ice Lines and the Formation of Giant Moons around Super-Jovian Planets

    NASA Astrophysics Data System (ADS)

    Heller, René; Pudritz, Ralph

    2015-06-01

    Most of the exoplanets with known masses at Earth-like distances to Sun-like stars are heavier than Jupiter, which raises the question of whether such planets are accompanied by detectable, possibly habitable moons. Here we simulate the accretion disks around super-Jovian planets and find that giant moons with masses similar to Mars can form. Our results suggest that the Galilean moons formed during the final stages of accretion onto Jupiter, when the circumjovian disk was sufficiently cool. In contrast to other studies, with our assumptions, we show that Jupiter was still feeding from the circumsolar disk and that its principal moons cannot have formed after the complete photoevaporation of the circumsolar nebula. To counteract the steady loss of moons into the planet due to type I migration, we propose that the water ice line around Jupiter and super-Jovian exoplanets acted as a migration trap for moons. Heat transitions, however, cross the disk during the gap opening within ?104 years, which makes them inefficient as moon traps and indicates a fundamental difference between planet and moon formation. We find that icy moons larger than the smallest known exoplanet can form at about 15-30 Jupiter radii around super-Jovian planets. Their size implies detectability by the Kepler and PLATO space telescopes as well as by the European Extremely Large Telescope. Observations of such giant exomoons would be a novel gateway to understanding planet formation, as moons carry information about the accretion history of their planets.

  16. Constraints on the mass of a habitable planet with water of nebular origin

    E-print Network

    Masahiro Ikoma; Hidenori Genda

    2006-06-06

    From an astrobiological point of view, special attention has been paid to the probability of habitable planets in extrasolar systems. The purpose of this study is to constrain a possible range of the mass of a terrestrial planet that can get water. We focus on the process of water production through oxidation of the atmospheric hydrogen--the nebular gas having been attracted gravitationally--by oxide available at the planetary surface. For the water production to work well on a planet, a sufficient amount of hydrogen and enough high temperature to melt the planetary surface are needed. We have simulated the structure of the atmosphere that connects with the protoplanetary nebula for wide ranges of heat flux, opacity, and density of the nebular gas. We have found both requirements are fulfilled for an Earth-mass planet for wide ranges of the parameters. We have also found the surface temperature of planets of planet of more than several Earth masses becomes a gas giant planet through runaway accretion of the nebular gas.

  17. RESOLVING THE sin(I) DEGENERACY IN LOW-MASS MULTI-PLANET SYSTEMS

    SciTech Connect

    Batygin, Konstantin; Laughlin, Gregory

    2011-04-01

    Long-term orbital evolution of multi-planet systems under tidal dissipation often converges to a stationary state, known as the tidal fixed point. The fixed point is characterized by a lack of oscillations in the eccentricities and apsidal alignment among the orbits. Quantitatively, the nature of the fixed point is dictated by mutual interactions among the planets as well as non-Keplerian effects. We show that if a roughly coplanar system hosts a hot, sub-Saturn mass planet, and is tidally relaxed, separation of planet-planet interactions and non-Keplerian effects in the equations of motion leads to a direct determination of the true masses of the planets. Consequently, a 'snap-shot' observational determination of the orbital state resolves the sin(I) degeneracy and opens up a direct avenue toward identification of the true lowest-mass exoplanets detected. We present an approximate, as well as a general, mathematical framework for computation of the line-of-sight inclination of secular systems, and apply our models illustratively to the 61 Vir system. We conclude by discussing the observability of planetary systems to which our method is applicable and we set our analysis into a broader context by presenting a current summary of the various possibilities for determining the physical properties of planets from observations of their orbital states.

  18. ORBITAL MIGRATION OF INTERACTING LOW-MASS PLANETS IN EVOLUTIONARY RADIATIVE TURBULENT MODELS

    SciTech Connect

    Horn, Brandon; Mac Low, Mordecai-Mark; Lyra, Wladimir; Sandor, Zsolt E-mail: wlyra@amnh.org E-mail: zsolt.sandor@uibk.ac.at

    2012-05-01

    The torques exerted by a locally isothermal disk on an embedded planet lead to rapid inward migration. Recent work has shown that modeling the thermodynamics without the assumption of local isothermality reveals regions where the net torque on an embedded planet is positive, leading to outward migration of the planet. When a region with negative torque lies directly exterior to this, planets in the inner region migrate outward and planets in the outer region migrate inward, converging where the torque is zero. We incorporate the torques from an evolving non-isothermal disk into an N-body simulation to examine the behavior of planets or planetary embryos interacting in the convergence zone. We find that mutual interactions do not eject objects from the convergence zone. Small numbers of objects in a laminar disk settle into near resonant orbits that remain stable over the 10 Myr periods that we examine. However, either or both increasing the number of planets or including a correlated, stochastic force to represent turbulence drives orbit crossings and mergers in the convergence zone. These processes can build gas giant cores with masses of order 10 Earth masses from sub-Earth mass embryos in 2-3 Myr.

  19. The Metallicity of Giant Planets

    NASA Astrophysics Data System (ADS)

    Thorngren, Daniel P.; Fortney, Jonathan

    2015-12-01

    Unique clues about the formation processes of giant planets can be found in their bulk compositions. Transiting planets provide us with bulk density determinations that can then be compared to models of planetary structure and evolution, to deduce planet bulk metallicities. At a given mass, denser planets have a higher mass fraction of metals. However, the unknown hot Jupiter "radius inflation" mechanism leads to under-dense planets that severely biases this work. Here we look at cooler transiting gas giants (Teff < 1000 K), which do not exhibit the radius inflation effect seen in their warmer cousins. We identified 40 such planets between 20 M_Earth and 20 M_Jup from the literature and used evolution models to determine their bulk heavy-element ("metal") mass. Several important trends are apparent. We see that all planets have at least ~10 M_Earth of metals, and that the mass of metal correlates strongly with the total mass of the planet. The heavy-element mass goes as the square root of the total mass. Both findings are consistent with the core accretion model. We also examined the effect of the parent star metallicity [Fe/H], finding that planets around high-metallicity stars are more likely to have large amounts of metal, but the relation appears weaker than previous studies with smaller sample sizes had suggested. We also looked for connections between bulk composition and planetary orbital parameters and stellar parameters, but saw no pattern, which is also an important result. This work can be directly compared to current and future outputs from planet formation models, including population synthesis.

  20. SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars

    NASA Astrophysics Data System (ADS)

    Almenara, J. M.; Damiani, C.; Bouchy, F.; Havel, M.; Bruno, G.; Hébrard, G.; Diaz, R. F.; Deleuil, M.; Barros, S. C. C.; Boisse, I.; Bonomo, A. S.; Montagnier, G.; Santerne, A.

    2015-03-01

    We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of 2.86 ± 0.35 MJup and a radius of 1.13 +0.26-0.18 RJup, and it orbits a G0, metallic ([ Fe/H ] = 0.35 ± 0.15) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of Teq = 1000 ± 45 K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of 2.82 ± 0.52 MJup and a radius of 1.45 ± 0.16 RJup, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the planet. On the other hand, KOI-680b has a much lower mass of 0.84 ± 0.15 MJup and requires less extra-dissipation to explain its uncommonly large radius of 1.99 ± 0.18 RJup. It is one of the biggest transiting planets characterized so far, and it orbits a subgiant F9-star well on its way to the red giant stage, with an orbital period of 8.6 days. With host stars of masses of 1.46 ± 0.17 M? and 1.54 ± 0.09 M?, respectively, KOI-206b, and KOI-680b are interesting objects for theories of formation and survival of short-period planets around stars more massive than the Sun. For those two targets, we also find signs of a possible distant additional companion in the system. Based on observations made with SOPHIE on the 1.93-m telescope at the Observatoire de Haute-Provence (CNRS), France.Figures 11-14 are available in electronic form at http://www.aanda.org

  1. THE EFFECT OF PLANET-PLANET SCATTERING ON THE SURVIVAL OF EXOMOONS

    SciTech Connect

    Gong Yanxiang; Zhou Jilin; Xie Jiwei; Wu Xiaomei E-mail: yxgong@nju.edu.cn

    2013-05-20

    Compared to the giant planets in the solar system, exoplanets have many remarkable properties, such as the prevalence of giant planets on eccentric orbits and the presence of hot Jupiters. Planet-planet scattering (PPS) between giant planets is a possible mechanism to interpret the above and other observed properties. If the observed giant planet architectures are indeed outcomes of PPS, such a drastic dynamical process must affect their primordial moon systems. In this Letter, we discuss the effect of PPS on the survival of exoplanets' regular moons. From an observational viewpoint, some preliminary conclusions are drawn from the simulations. (1) PPS is a destructive process to the moon systems; single planets on eccentric orbits are not ideal moon-search targets. (2) If hot Jupiters formed through PPS, their original moons have little chance of survival. (3) Planets in multiple systems with small eccentricities are more likely to hold their primordial moons. (4) Compared with lower-mass planets, massive planets in multiple systems may not be the preferred moon-search targets if the system underwent a PPS history.

  2. GAP OPENING BY EXTREMELY LOW-MASS PLANETS IN A VISCOUS DISK

    SciTech Connect

    Duffell, Paul C.; MacFadyen, Andrew I. E-mail: macfadyen@nyu.edu

    2013-05-20

    By numerically integrating the compressible Navier-Stokes equations in two dimensions, we calculate the criterion for gap formation by a very low mass (q {approx} 10{sup -4}) protoplanet on a fixed orbit in a thin viscous disk. In contrast with some previously proposed gap-opening criteria, we find that a planet can open a gap even if the Hill radius is smaller than the disk scale height. Moreover, in the low-viscosity limit, we find no minimum mass necessary to open a gap for a planet held on a fixed orbit. In particular, a Neptune-mass planet will open a gap in a minimum mass solar nebula with suitably low viscosity ({alpha} {approx}< 10{sup -4}). We find that the mass threshold scales as the square root of viscosity in the low mass regime. This is because the gap width for critical planet masses in this regime is a fixed multiple of the scale height, not of the Hill radius of the planet.

  3. Exoplanet dynamics. Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars.

    PubMed

    Leconte, Jérémy; Wu, Hanbo; Menou, Kristen; Murray, Norman

    2015-02-01

    Planets in the habitable zone of lower-mass stars are often assumed to be in a state of tidally synchronized rotation, which would considerably affect their putative habitability. Although thermal tides cause Venus to rotate retrogradely, simple scaling arguments tend to attribute this peculiarity to the massive Venusian atmosphere. Using a global climate model, we show that even a relatively thin atmosphere can drive terrestrial planets' rotation away from synchronicity. We derive a more realistic atmospheric tide model that predicts four asynchronous equilibrium spin states, two being stable, when the amplitude of the thermal tide exceeds a threshold that is met for habitable Earth-like planets with a 1-bar atmosphere around stars more massive than ~0.5 to 0.7 solar mass. Thus, many recently discovered terrestrial planets could exhibit asynchronous spin-orbit rotation, even with a thin atmosphere. PMID:25592420

  4. ExtraSolar Planets How did we find the planets?

    E-print Network

    Walter, Frederick M.

    ExtraSolar Planets #12;How did we find the planets? · Mercury, Venus, Mars, Jupiter, Saturn: orbital motions · KBOs: motions #12;How do we find ExtraSolar Planets? #12;How do we find ExtraSolar Planets? · Back to Astronomy... #12;Finding Extrasolar Planets. I Direct Searches Direct searches

  5. Exobiology, Jupiter and life.

    NASA Technical Reports Server (NTRS)

    Molton, P. M.

    1972-01-01

    Recent experiments in an environmental chamber have shown that not even hardy terrestrial bacteria can survive on the Martian surface. The planet Jupiter is now considered by many to be the most likely place to find nonterrestrial life. Atmospheric simulation experiments for Jupiter that have been performed involve spark or semicorona discharges in mixtures of methane and ammonia at room temperature and a pressure lower than atmospheric. Terrestrial microorganisms have been shown capable of surviving 24 hr under a range of possible Jovian atmospheric conditions. The final mode of approach to the question of Jovian life concerns theoretical studies on the sort of chemical systems from which life could be generated.

  6. Discovery and spectroscopy of the young jovian planet 51 Eri b with the Gemini Planet Imager.

    PubMed

    Macintosh, B; Graham, J R; Barman, T; De Rosa, R J; Konopacky, Q; Marley, M S; Marois, C; Nielsen, E L; Pueyo, L; Rajan, A; Rameau, J; Saumon, D; Wang, J J; Patience, J; Ammons, M; Arriaga, P; Artigau, E; Beckwith, S; Brewster, J; Bruzzone, S; Bulger, J; Burningham, B; Burrows, A S; Chen, C; Chiang, E; Chilcote, J K; Dawson, R I; Dong, R; Doyon, R; Draper, Z H; Duchêne, G; Esposito, T M; Fabrycky, D; Fitzgerald, M P; Follette, K B; Fortney, J J; Gerard, B; Goodsell, S; Greenbaum, A Z; Hibon, P; Hinkley, S; Cotten, T H; Hung, L-W; Ingraham, P; Johnson-Groh, M; Kalas, P; Lafreniere, D; Larkin, J E; Lee, J; Line, M; Long, D; Maire, J; Marchis, F; Matthews, B C; Max, C E; Metchev, S; Millar-Blanchaer, M A; Mittal, T; Morley, C V; Morzinski, K M; Murray-Clay, R; Oppenheimer, R; Palmer, D W; Patel, R; Perrin, M D; Poyneer, L A; Rafikov, R R; Rantakyrö, F T; Rice, E L; Rojo, P; Rudy, A R; Ruffio, J-B; Ruiz, M T; Sadakuni, N; Saddlemyer, L; Salama, M; Savransky, D; Schneider, A C; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vasisht, G; Wallace, J K; Ward-Duong, K; Wiktorowicz, S J; Wolff, S G; Zuckerman, B

    2015-10-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10(-6) and an effective temperature of 600 to 750 kelvin. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold-start" core-accretion process that may have formed Jupiter. PMID:26272904

  7. Discovery and spectroscopy of the young jovian planet 51 Eri b with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Macintosh, B.; Graham, J. R.; Barman, T.; De Rosa, R. J.; Konopacky, Q.; Marley, M. S.; Marois, C.; Nielsen, E. L.; Pueyo, L.; Rajan, A.; Rameau, J.; Saumon, D.; Wang, J. J.; Patience, J.; Ammons, M.; Arriaga, P.; Artigau, E.; Beckwith, S.; Brewster, J.; Bruzzone, S.; Bulger, J.; Burningham, B.; Burrows, A. S.; Chen, C.; Chiang, E.; Chilcote, J. K.; Dawson, R. I.; Dong, R.; Doyon, R.; Draper, Z. H.; Duchêne, G.; Esposito, T. M.; Fabrycky, D.; Fitzgerald, M. P.; Follette, K. B.; Fortney, J. J.; Gerard, B.; Goodsell, S.; Greenbaum, A. Z.; Hibon, P.; Hinkley, S.; Cotten, T. H.; Hung, L.-W.; Ingraham, P.; Johnson-Groh, M.; Kalas, P.; Lafreniere, D.; Larkin, J. E.; Lee, J.; Line, M.; Long, D.; Maire, J.; Marchis, F.; Matthews, B. C.; Max, C. E.; Metchev, S.; Millar-Blanchaer, M. A.; Mittal, T.; Morley, C. V.; Morzinski, K. M.; Murray-Clay, R.; Oppenheimer, R.; Palmer, D. W.; Patel, R.; Perrin, M. D.; Poyneer, L. A.; Rafikov, R. R.; Rantakyrö, F. T.; Rice, E. L.; Rojo, P.; Rudy, A. R.; Ruffio, J.-B.; Ruiz, M. T.; Sadakuni, N.; Saddlemyer, L.; Salama, M.; Savransky, D.; Schneider, A. C.; Sivaramakrishnan, A.; Song, I.; Soummer, R.; Thomas, S.; Vasisht, G.; Wallace, J. K.; Ward-Duong, K.; Wiktorowicz, S. J.; Wolff, S. G.; Zuckerman, B.

    2015-10-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10-6 and an effective temperature of 600 to 750 kelvin. For this age and luminosity, “hot-start” formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the “cold-start” core-accretion process that may have formed Jupiter.

  8. Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager

    E-print Network

    Macintosh, B; Barman, T; De Rosa, R J; Konopacky, Q; Marley, M S; Marois, C; Nielsen, E L; Pueyo, L; Rajan, A; Rameau, J; Saumon, D; Wang, J J; Ammons, M; Arriaga, P; Artigau, E; Beckwith, S; Brewster, J; Bruzzone, S; Bulger, J; Burningham, B; Burrows, A S; Chen, C; Chiang, E; Chilcote, J K; Dawson, R I; Dong, R; Doyon, R; Draper, Z H; Duchêne, G; Esposito, T M; Fabrycky, D; Fitzgerald, M P; Follette, K B; Fortney, J J; Gerard, B; Goodsell, S; Greenbaum, A Z; Hibon, P; Hinkley, S; Hufford, T; Hung, L -W; Ingraham, P; Johnson-Groh, M; Kalas, P; Lafreniere, D; Larkin, J E; Lee, J; Line, M; Long, D; Maire, J; Marchis, F; Matthews, B C; Max, C E; Metchev, S; Millar-Blanchaer, M A; Mittal, T; Morley, C V; Morzinski, K M; Murray-Clay, R; Oppenheimer, R; Palmer, D W; Patel, R; Patience, J; Perrin, M D; Poyneer, L A; Rafikov, R R; Rantakyrö, F T; Rice, E; Rojo, P; Rudy, A R; Ruffio, J -B; Ruiz, M T; Sadakuni, N; Saddlemyer, L; Salama, M; Savransky, D; Schneider, A C; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vasisht, G; Wallace, J K; Ward-Duong, K; Wiktorowicz, S J; Wolff, S G; Zuckerman, B

    2015-01-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric composition and luminosity, which is influenced by their formation mechanism. Using the Gemini Planet Imager, we discovered a planet orbiting the \\$sim$20 Myr-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water vapor absorption. Modeling of the spectra and photometry yields a luminosity of L/LS=1.6-4.0 x 10-6 and an effective temperature of 600-750 K. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold- start" core accretion process that may have formed Jupiter.

  9. Probing the Spatial Distribution of Extrasolar Planets with Gravitational Microlensing

    E-print Network

    Cheongho Han; Young Woon Kang

    2003-03-14

    Under the current microlensing planet search strategy of monitoring events caused by stellar-mass lenses, only planets located within a narrow region of separations from central stars can be effectively detected. However, with the dramatic increase of the monitoring frequency, two additional populations of free-floating and wide-orbit planets can be detected. In this paper, we investigate the lensing properties of events caused by wide-orbit planets and find that the light curves of a significant fraction of these events will exhibit signatures of central stars, enabling one to distinguish them from those caused by free-floating planets. Due to the large primary/planet mass ratio, the effect of the central star endures to considerable separations. We find that for a Jupiter-mass planet the signatures of the central star can be detected with fractional deviations of > 5% from the best-fitting single-lens light curves for > 80% of events caused by bound planets with separations planets with separations up to 20 AU. Therefore, detecting a large sample of these events will provide useful information about the distribution of extrasolar planets around their central stars. Proper estimation of the probability of distinguishing events caused by wide-orbit planets from those caused by free-floating planets will be important for the correct determination of the frequency of free-floating planets, whose microlensing sample will be contaminated by wide-orbits planets.

  10. ARTIST'S CONCEPT -- 'HOT JUPITER' AROUND THE STAR HD 209458

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an artist's impression of the gas-giant planet orbiting the yellow, Sun-like star HD 209458, 150 light-years from Earth. Astronomers used NASA's Hubble Space Telescope to look at this world and make the first direct detection of an atmosphere around an extrasolar planet. The planet was not directly seen by Hubble. Instead, the presence of sodium was detected in light filtered through the planet's atmosphere when it passed in front of its star as seen from Earth (an event called a transit). The planet was discovered in 1999 by its subtle gravitational pull on the star. The planet is 70 percent the mass of Jupiter, the largest planet in our solar system. Its orbit is tilted nearly edge-on to Earth, which allows repeated transit observations. The planet is merely 4 million miles from the star. The distance between the pair is so close that the yellow star looms in the sky, with an angular diameter 23 times larger than the full Moon's diameter as seen from Earth, and glows 500 times brighter than our Sun. At this precarious distance the planet's atmosphere is heated to 2000 degrees Fahrenheit (1100 degrees Celsius). But the planet is big enough to hold onto its seething atmosphere. Illustration Credit: NASA and Greg Bacon (STScI/AVL)

  11. Direct imaging of multiple planets orbiting the star HR 8799.

    PubMed

    Marois, Christian; Macintosh, Bruce; Barman, Travis; Zuckerman, B; Song, Inseok; Patience, Jennifer; Lafrenière, David; Doyon, René

    2008-11-28

    Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step toward imaging Earth-like planets. Imaging detections are challenging because of the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our solar system. PMID:19008415

  12. Direct imaging of multiple planets orbiting the star HR 8799

    SciTech Connect

    Marois, C; Macintosh, B; Barman, T; Zuckerman, B; Song, I; Patience, J; Lafreniere, D; Doyon, R

    2008-10-14

    Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step towards imaging Earth-like planets. Imaging detections are challenging due to the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter-clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our Solar System.

  13. Formation and structure of the three Neptune-mass planets system around HD69830

    E-print Network

    Yann Alibert; Isabelle Baraffe; Willy Benz; Gilles Chabrier; Christophe Mordasini; Christophe Lovis; Michel Mayor; Francesco Pepe; Francois Bouchy; Didier Queloz; Stephane Udry

    2006-07-10

    Since the discovery of the first giant planet outside the solar system in 1995 (Mayor & Queloz 1995), more than 180 extrasolar planets have been discovered. With improving detection capabilities, a new class of planets with masses 5-20 times larger than the Earth, at close distance from their parent star is rapidly emerging. Recently, the first system of three Neptune-mass planets has been discovered around the solar type star HD69830 (Lovis et al. 2006). Here, we present and discuss a possible formation scenario for this planetary system based on a consistent coupling between the extended core accretion model and evolutionary models (Alibert et al. 2005a, Baraffe et al. 2004,2006). We show that the innermost planet formed from an embryo having started inside the iceline is composed essentially of a rocky core surrounded by a tiny gaseous envelope. The two outermost planets started their formation beyond the iceline and, as a consequence, accrete a substantial amount of water ice during their formation. We calculate the present day thermodynamical conditions inside these two latter planets and show that they are made of a rocky core surrounded by a shell of fluid water and a gaseous envelope.

  14. WARM JUPITERS NEED CLOSE ''FRIENDS'' FOR HIGH-ECCENTRICITY MIGRATION—A STRINGENT UPPER LIMIT ON THE PERTURBER'S SEPARATION

    SciTech Connect

    Dong, Subo; Katz, Boaz; Socrates, Aristotle

    2014-01-20

    We propose a stringent observational test on the formation of warm Jupiters (gas-giant planets with 10 days ? P ? 100 days) by high-eccentricity (high-e) migration mechanisms. Unlike hot Jupiters, the majority of observed warm Jupiters have pericenter distances too large to allow efficient tidal dissipation to induce migration. To access the close pericenter required for migration during a Kozai-Lidov cycle, they must be accompanied by a strong enough perturber to overcome the precession caused by general relativity, placing a strong upper limit on the perturber's separation. For a warm Jupiter at a ? 0.2 AU, a Jupiter-mass (solar-mass) perturber is required to be ? 3 AU (? 30 AU) and can be identified observationally. Among warm Jupiters detected by radial velocities (RVs), ? 50% (5 out of 9) with large eccentricities (e ? 0.4) have known Jovian companions satisfying this necessary condition for high-e migration. In contrast, ? 20% (3 out of 17) of the low-e (e ? 0.2) warm Jupiters have detected additional Jovian companions, suggesting that high-e migration with planetary perturbers may not be the dominant formation channel. Complete, long-term RV follow-ups of the warm-Jupiter population will allow a firm upper limit to be put on the fraction of these planets formed by high-e migration. Transiting warm Jupiters showing spin-orbit misalignments will be interesting to apply our test. If the misalignments are solely due to high-e migration as commonly suggested, we expect that the majority of warm Jupiters with low-e (e ? 0.2) are not misaligned, in contrast with low-e hot Jupiters.

  15. Maps and Masses of Transiting Exoplanets: Towards New Insights into Atmospheric and Interior Properties of Planets

    E-print Network

    de Wit, Julien

    2015-01-01

    With over 1800 planets discovered outside of the Solar System in the past two decades, the field of exoplanetology has broadened our perspective on planetary systems. Research priorities are now moving from planet detection to planet characterization. In this context, transiting exoplanets are of special interest due to the wealth of data made available by their orbital configuration. Here, I introduce two methods to gain new insights into the atmospheric and interior properties of exoplanets. The first method aims to map an exoplanet's atmosphere based on the scanning obtained while it is occulted by its host star. I introduce the basics of eclipse mapping, its caveats, and a framework to mitigate their effects via global analyses including transits, phase curves, and radial velocity measurements. I use this method to create the first 2D map and the first cloud map of an exoplanet for the hot-Jupiters HD189733b and Kepler-7b, respectively. Ultimately temperature, composition, and circulation patterns could b...

  16. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    E-print Network

    Wolfgang, Angie; Ford, Eric B

    2015-01-01

    The Kepler Mission has discovered thousands of planets with radii $Neptunes and super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern for these studies is therefore how to map the measured radii to mass estimates for this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters. We analyze how the det...

  17. Constraint of a planet mass from the depth and width of an observed gap on a protoplanetary disk

    NASA Astrophysics Data System (ADS)

    Kanagawa, Kazuhiro; Muto, Takayuki; Tanaka, Hidekazu; Tanigawa, Takayuki; Takeuchi, Taku

    2015-12-01

    In a protoplanetary disk, a large planet is able to create the so-called disk gap, which is a low gas density region along the planet's orbit, due to the gravitational interaction between the disc and the planet. The gap formation induced by the giant planet is a possible mechanism to explain the formation of the so-called pre-transition disks with a ring gap structure. If the gap is created by the planet, the gap shape, i.e., the depth and width, would represent the mass and location of the planet. At the present stage, many pre-transition disks have been observed by e.g., ALMA and Subaru telescopes. It is important for us to examine what properties of the planet are constrained from the observed gap if the planet is in the gap.We derived the relation between the depth of the observed gap and the planet mass in the gap based on the analytical model (Kanagawa et al. 2015a). This relation is a powerful tool to estimate the planet mass from the direct imaging of gaps in protoplanetary disks. We also applied this relation to the image of HL Tau' disk given by a part of the 2014 ALMA long baseline camphene and estimate the planet masses (Kanagawa et al 2015b).We also performed the numerical hydrodynamic simulation with the FARGO which is well-known code for the rotation disk, and found that the gap width becomes wider with a square root of the planet mass. Using this empirical relation for the gap width, we can also constrain the planet mass from the gap width.I'll talk about the relation between the gap depth, width and the planet, and the method for estimating the planet mass from the observed image of the disks.

  18. The HARPS search for southern extra-solar planets. XVII. Super-Earth and Neptune-mass planets in multiple planet systems HD47186 and HD181433

    E-print Network

    Bouchy, F; Lovis, C; Udry, S; Benz, W; Bertaux, J-L; Delfosse, X; Mordasini, C; Pepe, F; Queloz, D; Ségransan, D

    2008-01-01

    This paper reports on the detection of two new multiple planet systems around solar-like stars HD47186 and HD181433. The first system includes a hot Neptune of 22.78 M_Earth at 4.08-days period and a Saturn of 0.35 M_Jup at 3.7-years period. The second system includes a Super-Earth of 7.5 M_Earth at 9.4-days period, a 0.64 M$_Jup at 2.6-years period as well as a third companion of 0.54 M_Jup with a period of about 6 years. These detections increase to 20 the number of close-in low-mass exoplanets (below 0.1 M_Jup) and strengthen the fact that 80% of these planets are in a multiple planetary systems.

  19. The HARPS search for southern extra-solar planets. XVII. Super-Earth and Neptune-mass planets in multiple planet systems HD47186 and HD181433

    E-print Network

    F. Bouchy; M. Mayor; C. Lovis; S. Udry; W. Benz; J-L Bertaux; X. Delfosse; C. Mordasini; F. Pepe; D. Queloz; D. Segransan

    2008-12-09

    This paper reports on the detection of two new multiple planet systems around solar-like stars HD47186 and HD181433. The first system includes a hot Neptune of 22.78 M_Earth at 4.08-days period and a Saturn of 0.35 M_Jup at 3.7-years period. The second system includes a Super-Earth of 7.5 M_Earth at 9.4-days period, a 0.64 M$_Jup at 2.6-years period as well as a third companion of 0.54 M_Jup with a period of about 6 years. These detections increase to 20 the number of close-in low-mass exoplanets (below 0.1 M_Jup) and strengthen the fact that 80% of these planets are in a multiple planetary systems.

  20. The High-Energy Radiation Environment of Planets around Low-Mass Stars

    NASA Astrophysics Data System (ADS)

    Shkolnik, Evgenya; Miles, Brittany; Barman, Travis; Peacock, Sarah

    2015-12-01

    Low-mass stars are the dominant planet hosts averaging about one planet per star. Many of these planets orbit in the canonical habitable zone (HZ) of the star where, if other conditions allowed, liquid water may exist on the surface.A planet’s habitability, including atmospheric retention, is strongly dependent on the star’s ultraviolet (UV) emission, which chemically modifies, ionizes, and even erodes the atmosphere over time including the photodissociation of important diagnostic molecules, e.g. H2O, CH4, and CO2. The UV spectral slope of a low-mass star can enhance atmospheric lifetimes, and increase the detectability of biologically generated gases. But, a different slope may lead to the formation of abiotic oxygen and ozone producing a false-positive biosignature for oxygenic photosynthesis. Realistic constraints on the incident UV flux over a planet’s lifetime are necessary to explore the cumulative effects on the evolution, composition, and fate of a HZ planetary atmosphere.NASA’s Galaxy Evolution Explorer (GALEX) provides a unique data set with which to study the broadband UV emission from many hundreds of M dwarfs. The GALEX satellite has imaged nearly 3/4 of the sky simultaneously in two UV bands: near-UV (NUV; 175–275 nm) and far-UV (FUV; 135–175 nm). With these data these, we are able to calculate the mean UV emission and its level of variability at these wavelengths over critical planet formation and evolution time scales to better understand the probable conditions in HZ planetary atmospheres.In the near future, dedicated CubeSats (miniaturized satellites for space research) to monitor M dwarf hosts of transiting exoplanets will provide the best opportunity to measure their UV variability, constrain the probabilities of detecting habitable (and inhabited) planets, and provide the correct context within which to interpret IR transmission and emission spectroscopy of transiting exoplanets.

  1. Detection of Extrasolar Planets by Transit Photometry

    NASA Technical Reports Server (NTRS)

    Borucki, William; Koch, David; Webster, Larry; Dunham, Edward; Witteborn, Fred; Jenkins, Jon; Caldwell, Douglas; Showen, Robert; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    A knowledge of other planetary systems that includes information on the number, size, mass, and spacing of the planets around a variety of star types is needed to deepen our understanding of planetary system formation and processes that give rise to their final configurations. Recent discoveries show that many planetary systems are quite different from the solar system in that they often possess giant planets in short period orbits. The inferred evolution of these planets and their orbital characteristics imply the absence of Earth-like planets near the habitable zone. Information on the properties of the giant-inner planets is now being obtained by both the Doppler velocity and the transit photometry techniques. The combination of the two techniques provides the mass, size, and density of the planets. For the planet orbiting star HD209458, transit photometry provided the first independent confirmation and measurement of the diameter of an extrasolar planet. The observations indicate a planet 1.27 the diameter of Jupiter with 0.63 of its mass (Charbonneau et al. 1999). The results are in excellent agreement with the theory of planetary atmospheres for a planet of the indicated mass and distance from a solar-like star. The observation of the November 23, 1999 transit of that planet made by the Ames Vulcan photometer at Lick Observatory is presented. In the future, the combination of the two techniques will greatly increase the number of discoveries and the richness of the science yield. Small rocky planets at orbital distances from 0.9 to 1.2 AU are more likely to harbor life than the gas giant planets that are now being discovered. However, new technology is needed to find smaller, Earth-like planets, which are about three hundred times less massive than Jupiter-like planets. The Kepler project is a space craft mission designed to discover hundreds of Earth-size planets in and near the habitable zone around a wide variety of stars. To demonstrate that the technology exists to find such small planets, our group has conducted an end-to-end system test. The results of the laboratory tests are presented and show that we are ready to start the search for Earth-size planets.

  2. ATMOSPHERIC CHEMISTRY IN GIANT PLANETS, BROWN DWARFS, AND LOW-MASS DWARF STARS. II. SULFUR AND PHOSPHORUS

    E-print Network

    ATMOSPHERIC CHEMISTRY IN GIANT PLANETS, BROWN DWARFS, AND LOW-MASS DWARF STARS. II. SULFUR to model sulfur and phosphorus chemistry in giant planets, brown dwarfs, and extrasolar giant planets (EGPs and approximately represents the atmospheric sulfur inventory. Silicon sulfide (SiS) is a potential tracer

  3. Measuring Masses and Densities of Small Planets found by NASA's Kepler Spacecraft with Radial Velocity Measurements from Keck/HIRES

    NASA Astrophysics Data System (ADS)

    Isaacson, Howard T.; Marcy, G.; Rowe, J.; Kepler Team

    2013-06-01

    We use the Keck telescope and HIRES spectrometer to measure the masses of Kepler planet candidates. Analysis of 22 Kepler-identified planetary systems, holding 42 transiting planets (candidates) and 8 newly discovered non-transiting planets are presented herein. Combining the planet radius measurements from Kepler with mass measurements from Keck, we constrain the bulk density of short period planets that range in size from 1.0 to 3.0 Earth radii. Extensive ground based observations made by the Kepler Follow-up Program (KFOP) have provided extensive details about each KOI. Reconnaissance spectroscopy was used to refine the stellar and planet properties of each KOI at an early stage. SME spectral analysis and asteroseismology, when available, are used to obtain the final stellar properties. Adaptive Optics and speckle imaging constrain the presence of background eclipsing binaries that could masquerade as transiting planets. By combining ground based follow-up observations with Kepler photometry, a false positive probability is calculated for each KOI. An MCMC analysis that combines both Kepler photometry and Keck radial velocity measurements determines the final orbital parameters and planet properties for each system. The resulting mass vs. radius diagram for the planets reveals that radii increase with mass monotonically, well represented by a power law for the smallest planets. This M-R relationship offers key insights about the internal composition of the planets and the division between rocky and gaseous planets.

  4. Microlensing Searches for Extrasolar Planets: Current Status and Future Prospects

    E-print Network

    B. Scott Gaudi

    2002-09-30

    I review results from, and future prospects for, microlensing searches for extrasolar planets. Analyses of well-sampled microlensing light curves by several collaborations have demonstrated that current searches are sensitive to Jupiter-mass planets with few AU separations from M-dwarfs in the Galactic bulge. To date, however, no unambiguous planetary detections have been made. Detailed analysis has shown that this null result implies that <33% of typical stars (i.e. M-dwarfs) in the Galactic bulge have Jupiter-mass companions with separations between 1.5 and 4 AU, and <45% have three-Jupiter-mass companions between 1 and 7 AU. The recent dramatic increase in the number of alerts per year will allow ongoing microlensing searches to probe companion fractions of a few percent within a few years.

  5. The Effect of Stellar Evolution on Migrating Warm Jupiters

    E-print Network

    Frewen, Shane

    2015-01-01

    Warm jupiters are an unexpected population of extrasolar planets that are too near to their host to have formed in situ, but distant enough to retain a significant eccentricity in the face of tidal damping. These planets are curiously absent around stars larger than two solar radii. We hypothesize that the warm jupiters are migrating due to Kozai-Lidov oscillations, which leads to transient episodes of high eccentricity and a consequent tidal decay. As their host evolves, such planets would be rapidly dragged in or engulfed at minimum periapse, leading to a rapid depletion of the population with increasing stellar radius, as is observed. Using numerical simulations, we determine the relationship between periapse distance and orbital migration rate for planets 0.1 to 10 Jupiter masses and with orbital periods between 10 and 100 days. We find that Kozai-Lidov oscillations effectively result in planetary removal early in the evolution of the host star, possibly accounting for the observed deficit. While the obse...

  6. FORMATION OF GIANT PLANETS BY DISK INSTABILITY ON WIDE ORBITS AROUND PROTOSTARS WITH VARIED MASSES

    SciTech Connect

    Boss, Alan P.

    2011-04-10

    Doppler surveys have shown that more massive stars have significantly higher frequencies of giant planets inside {approx}3 AU than lower mass stars, consistent with giant planet formation by core accretion. Direct imaging searches have begun to discover significant numbers of giant planet candidates around stars with masses of {approx}1 M{sub sun} to {approx}2 M{sub sun} at orbital distances of {approx}20 AU to {approx}120 AU. Given the inability of core accretion to form giant planets at such large distances, gravitational instabilities of the gas disk leading to clump formation have been suggested as the more likely formation mechanism. Here, we present five new models of the evolution of disks with inner radii of 20 AU and outer radii of 60 AU, for central protostars with masses of 0.1, 0.5, 1.0, 1.5, and 2.0 M{sub sun}, in order to assess the likelihood of planet formation on wide orbits around stars with varied masses. The disk masses range from 0.028 M{sub sun} to 0.21 M{sub sun}, with initial Toomre Q stability values ranging from 1.1 in the inner disks to {approx}1.6 in the outer disks. These five models show that disk instability is capable of forming clumps on timescales of {approx}10{sup 3} yr that, if they survive for longer times, could form giant planets initially on orbits with semimajor axes of {approx}30 AU to {approx}70 AU and eccentricities of {approx}0 to {approx}0.35, with initial masses of {approx}1 M{sub Jup} to {approx}5 M{sub Jup}, around solar-type stars, with more protoplanets forming as the mass of the protostar (and protoplanetary disk) is increased. In particular, disk instability appears to be a likely formation mechanism for the HR 8799 gas giant planetary system.

  7. Measurement of Planet Masses with Transit Timing Variations Due to Synodic “Chopping” Effects

    NASA Astrophysics Data System (ADS)

    Deck, Katherine M.; Agol, Eric

    2015-04-01

    Gravitational interactions between planets in transiting exoplanetary systems lead to variations in the times of transit that are diagnostic of the planetary masses and the dynamical state of the system. Here we show that synodic “chopping” contributions to these transit timing variations (TTVs) can be used to uniquely measure the masses of planets without full dynamical analyses involving direct integration of the equations of motion. We present simple analytic formulae for the chopping signal, which are valid (generally \\lt 10% error) for modest eccentricities e? 0.1. Importantly, these formulae primarily depend on the mass of the perturbing planet, and therefore the chopping signal can be used to break the mass/free-eccentricity degeneracy, which can appear for systems near first-order mean motion resonances. Using a harmonic analysis, we apply these TTV formulae to a number of Kepler systems, which had been previously modeled with full dynamical analyses. We show that when chopping is measured, the masses of both planets can be determined uniquely, in agreement with previous results, but without the need for numerical orbit integrations. This demonstrates how mass measurements from TTVs may primarily arise from an observable chopping signal. The formula for chopping can also be used to predict the number of transits and timing precision required for future observations, such as those made by TESS or PLATO, in order to infer planetary masses through analysis of TTVs.

  8. MOA 2011-BLG-028Lb: a Neptune-mass Microlensing Planet in the Galactic Bulge

    E-print Network

    Skowron, J; Poleski, R; Koz?owski, S; Szyma?ski, M K; Wyrzykowski, ?; Ulaczyk, K; Pietrukowicz, P; Pietrzy?ski, G; Soszy?ski, I; Abe, F; Bennett, D P; Bhattacharya, A; Bond, I A; Freeman, M; Fukui, A; Hirao, Y; Itow, Y; Koshimoto, N; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Nagakane, M; Ohnishi, K; Rattenbury, N; Saito, To; Sullivan, D J; Sumi, T; Suzuki, D; Tristram, P J; Yonehara, A; Dominik, M; Jørgensen, U G; Bozza, V; Harpsøe, K; Hundertmark, M; Skottfelt, J

    2015-01-01

    We present the discovery of a Neptune-mass planet orbiting a 0.8 +- 0.3 M_Sun star in the Galactic bulge. The planet manifested itself during the microlensing event MOA 2011-BLG-028/OGLE-2011-BLG-0203 as a low-mass companion to the lens star. The analysis of the light curve provides the measurement of the mass ratio: (1.2 +- 0.2) x 10^-4, which indicates the mass of the planet to be 12-60 Earth masses. The lensing system is located at 7.3 +- 0.7 kpc away from the Earth near the direction to Baade's Window. The projected separation of the planet, at the time of the microlensing event, was 3.1-5.2 AU. Although the "microlens parallax" effect is not detected in the light curve of this event, preventing the actual mass measurement, the uncertainties of mass and distance estimation are narrowed by the measurement of the source star proper motion on the OGLE-III images spanning eight years, and by the low amount of blended light seen, proving that the host star cannot be too bright and massive. We also discuss the ...

  9. Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism

    E-print Network

    M. Nagasawa; S. Ida; T. Bessho

    2008-01-09

    We have investigated the formation of close-in extrasolar giant planets through a coupling effect of mutual scattering, Kozai mechanism, and tidal circularization, by orbital integrations. We have carried out orbital integrations of three planets with Jupiter-mass, directly including the effect of tidal circularization. We have found that in about 30% runs close-in planets are formed, which is much higher than suggested by previous studies. We have found that Kozai mechanism by outer planets is responsible for the formation of close-in planets. During the three-planet orbital crossing, the Kozai excitation is repeated and the eccentricity is often increased secularly to values close enough to unity for tidal circularization to transform the inner planet to a close-in planet. Since a moderate eccentricity can remain for the close-in planet, this mechanism may account for the observed close-in planets with moderate eccentricities and without nearby secondary planets. Since these planets also remain a broad range of orbital inclinations (even retrograde ones), the contribution of this process would be clarified by more observations of Rossiter-McLaughlin effects for transiting planets.

  10. HOW DRY IS THE BROWN DWARF DESERT? QUANTIFYING THE RELATIVE NUMBER OF PLANETS, BROWN DWARFS, AND STELLAR COMPANIONS AROUND NEARBY SUN-LIKE STARS

    E-print Network

    Lineweaver, Charles H.

    . The minimum number of companions per unit interval in log mass (the driest part of the desert) is at M ¼ 31þ25 and describe it quantitatively. With decreasing mass, the companion mass function drops by almost 2 orders of magnitude from brown dwarfs to Jupiter-mass planets. The slopes of the planetary and stellar companion mass

  11. The Effect of Composition on the Evolution of Giant and Intermediate-Mass Planets

    E-print Network

    Vazan, A; Podolak, M; Helled, R

    2013-01-01

    We model the evolution of planets with various masses and compositions. We investigate the effects of the composition and its depth dependence on the long-term evolution of the planets. The effects of opacity and stellar irradiation are also considered. It is shown that the change in radius due to various compositions can be significantly smaller than the change in radius caused by the opacity. Irradiation also affects the planetary contraction but is found to be less important than the opacity effects. We suggest that the mass-radius relationship used for characterization of observed extrasolar planets should be taken with great caution since different physical conditions can result in very different mass-radius relationships.

  12. Dark Compact Planets

    E-print Network

    Laura Tolos; Juergen Schaffner-Bielich

    2015-07-29

    We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron star matter and white dwarf material. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from few Km to few hundred Km for weakly interacting dark matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be formed primordially and accrete white dwarf material subsequently. They could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 ${\\rm M}_{\\odot}$ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, $10^{-6}{\\rm M}_\\odot$.

  13. Dark Compact Planets

    E-print Network

    Tolos, Laura

    2015-01-01

    We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron star matter and white dwarf material. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from few Km to few hundred Km for weakly interacting dark matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be formed primordially and accrete white dwarf material subsequently. They could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 ${\\rm M}_{\\odot}$ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, $10^{-6}{\\rm M}_\\odot$.

  14. Dark compact planets

    NASA Astrophysics Data System (ADS)

    Tolos, Laura; Schaffner-Bielich, Jürgen

    2015-12-01

    We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron-star matter and white-dwarf material. We consider non-self annihilating dark matter with an equation of state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from a few Km to few hundred Km for weakly interacting dark matter which are stabilized by the mutual presence of dark matter and compact star matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 M? pulsars set limits on the amount of dark matter inside neutron stars which is, at most, 1 0-6 M? .

  15. The effect of planets beyond the ice line on the accretion of volatiles by habitable-zone rocky planets

    SciTech Connect

    Quintana, Elisa V.; Lissauer, Jack J.

    2014-05-01

    Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 M {sub ?} to 1 M {sub J}) in Jupiter's orbit at ?5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.

  16. Structure and Evolution of Internally Heated Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Youdin, Andrew N.

    2015-11-01

    The transit radii of many close-in extrasolar giant planets, or "hot Jupiters," are systematically larger than those expected from models considering only cooling from an initial high-entropy state. Though these planets receive strong irradiation, with equilibrium temperatures of 1000-2500 Kelvin, the absorption of stellar incident flux in the upper atmosphere alone cannot explain these anomalous radii. More promising mechanisms involve irradiation-driven meteorological activity, which penetrates much deeper into the planet than direct stellar heating. This circulation can lead to large-scale mixing and downward transport of kinetic energy, both processes whereby a fraction of the stellar incident power is transported downwards to the interior of the planet. Here we consider how deposition of heat at different pressure levels or structural locations within a planet affects the resulting evolution. To do so, we run global gas giant evolutionary models with with the stellar structure code MESA including additional energy dissipation. We find that relatively shallow atmospheric heating alone can explain the transit radii of the hot Jupiter sample, but heating in the convective zone is an order of magnitude more efficient regardless of exact location. Additionally, a small difference in atmospheric heating location can have a significant effect on radius evolution, especially near the radiative-convective boundary. The most efficient location to heat the planet is at the radiative-convective boundary or deeper. We expect that shear instabilities at this interface may naturally explain energy dissipation at the radiative-convective boundary, which typically lies at a pressure of ~1 kilobar after 5 Gyr for a planet with the mass and incident stellar flux of HD 209458b. Hence, atmospheric processes are most efficient at explaining the bloated radii of hot Jupiters if they can transport incident stellar power downwards to the top of the inner convective zone.

  17. The formation of Pegasi planets: fluid-dynamics, mass-function and observational tests

    NASA Astrophysics Data System (ADS)

    Wuchterl, G.

    2006-02-01

    Fluid-dynamical models based on the planetesimal hypothesis show that Pegasi-planets may form near their stars if sufficiently large reservoirs of gas and solids are available. The conventional minimum mass nebula cannot provide such reservoirs inside ?1 AU, but more generally, gravitationally stable nebulae do. Alternatively Pegasi planets might form in a special giant planet formation region, further out in the nebula and subsequently migrate to their present-day orbits. Three observational tests distinguish between the two scenarii: (1) the existence of Hot Neptunes, (2) birthplace exclusion in binaries, and (3) Hill-exclusion stability criteria. Scenario (1) uses the fact that migrating planets with about 10 Earth masses usually accrete gas. Scenario (2) uses the absence of an `appropriate' birth-place, and (3) the fact the Hill-spheres shrink as planets migrate inwards with increasing speed. For the in-situ formation-hypothesis the evolution of a Pegasi planet is calculated for the first 200 Myr from planetesimal accretion and the fluid-dynamics of gas-accretion with spherical symmetry.

  18. Discovering Jupiter. II

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Data derived from Pioneer 10 and Pioneer 11 and other sources on the Jovian magnetosphere, the circum-Jovian radiation belts, and Jupiter's radio emission are presented at some length, descriptions are given of the principal Jovian satellites (Io, Europa, Ganymede, Callisto), and inferences are drawn on the origin of the planet and its place in the solar system. The inner, middle, and outer regions of the magnetosphere, the bow shock wave, and the particularly heavy intensity of the inner radiation belt region (within 1.44 million km of the planet) are discussed. All of the major satellites except Callisto lie immersed in the intense radiation belts. Jupiter's failure to become a stellar companion to the sun, Io's action in 'switching on' Jovian radio emission, and other Pioneer discoveries relating to asteroids, the solar system in general, and trans-Jovian space, are discussed

  19. TOO LITTLE, TOO LATE: HOW THE TIDAL EVOLUTION OF HOT JUPITERS AFFECTS TRANSIT SURVEYS OF CLUSTERS

    SciTech Connect

    Debes, John H.; Jackson, Brian

    2010-11-10

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense Hubble Space Telescope search for transits. We find that in older clusters, one expects to detect fewer transiting planets by a factor of 2 for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of the semimajor axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  20. Too Little, Too Late: How the Tidal Evolution of Hot Jupiters Affects Transit Surveys of Clusters

    NASA Technical Reports Server (NTRS)

    Debes, John H.; Jackson, Brian

    2010-01-01

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  1. Asynchronous rotation of Earth-like planets in the habitable zone of lower-mass stars

    E-print Network

    Leconte, Jérémy; Menou, Kristen; Murray, Norman

    2015-01-01

    Planets in the habitable zone of lower-mass stars are often assumed to be in a state of tidally synchronized rotation, which would considerably affect their putative habitability. Although thermal tides cause Venus to rotate retrogradely, simple scaling arguments tend to attribute this peculiarity to the massive Venusian atmosphere. Using a global climate model, we show that even a relatively thin atmosphere can drive terrestrial planets' rotation away from synchronicity. We derive a more realistic atmospheric tide model that predicts four asynchronous equilibrium spin states, two being stable, when the amplitude of the thermal tide exceeds a threshold that is met for habitable Earth-like planets with a 1-bar atmosphere around stars more massive than 0.5-0.7Msun. Thus, many recently discovered terrestrial planets could exhibit asynchronous spin-orbit rotation, even with a thin atmosphere.

  2. The Kepler Mission: Search for Habitable Planets

    NASA Technical Reports Server (NTRS)

    Borucki, William; Likins, B.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    Detecting extrasolar terrestrial planets orbiting main-sequence stars is of great interest and importance. Current ground-based methods are only capable of detecting objects about the size or mass of Jupiter or larger. The difficulties encountered with direct imaging of Earth-size planets from space are expected to be resolved in the next twenty years. Spacebased photometry of planetary transits is currently the only viable method for detection of terrestrial planets (30-600 times less massive than Jupiter). This method searches the extended solar neighborhood, providing a statistically large sample and the detailed characteristics of each individual case. A robust concept has been developed and proposed as a Discovery-class mission. Its capabilities and strengths are presented.

  3. Evolution of Giant Planets Close to the Roche Limit

    NASA Astrophysics Data System (ADS)

    Valsecchi, Francesca

    2015-12-01

    Two formation models have been proposed to explain hot Jupiters’ tight orbits. These could have migrated inward in a disk (disk migration), or they could have formed via tidal circularization of an orbit made highly eccentric following gravitational interactions with a companion (high-eccentricity migration). I will show how current observations coupled with a detailed treatment of tides can be used to constrain both hot Jupiter formation and tidal dissipation theories.Eventually, stellar tides will cause the orbits of many hot Jupiters to decay down to their Roche limit. Using a detailed binary mass transfer model we show how a hot Jupiter undergoing a phase of Roche-lobe overflow (RLO) leads to lower-mass planets in orbits of a few days. The remnant planets have a rocky core and some amount of envelope material, which is slowly removed via photo-evaporation at nearly constant orbital period; these have properties resembling many of the observed super-Earths and sub-Neptunes. For these remnant planets we also predict an anti-correlation between mass and orbital period; very low-mass planets in ultra-short periods cannot be produced through this type of evolution.

  4. Interiors of giant planets inside and outside the solar system.

    PubMed

    Guillot, T

    1999-10-01

    An understanding of the structure and composition of the giant planets is rapidly evolving because of (i) high-pressure experiments with the ability to study metallic hydrogen and define the properties of its equation of state and (ii) spectroscopic and in situ measurements made by telescopes and satellites that allow an accurate determination of the chemical composition of the deep atmospheres of the giant planets. However, the total amount of heavy elements that Jupiter, Saturn, Uranus, and Neptune contain remains poorly constrained. The discovery of extrasolar giant planets with masses ranging from that of Saturn to a few times the mass of Jupiter opens up new possibilities for understanding planet composition and formation. Evolutionary models predict that gaseous extrasolar giant planets should have a variety of atmospheric temperatures and chemical compositions, but the radii are estimated to be close to that of Jupiter (between 0.9 and 1.7 Jupiter radii), provided that they contain mostly hydrogen and helium. PMID:10506563

  5. Planets around Giant Stars: Results from the Lick Survey

    NASA Astrophysics Data System (ADS)

    Quirrenbach, Andreas; Reffert, Sabine; Trifonov, Trifon; Bergmann, Christoph; Schwab, Christian

    2015-12-01

    We present results from a radial-velocity survey of 373 giant stars at Lick Observatory, which started in 1999. We have detected planets around 15 of these stars; an additional 20 stars host planet candidates. Companions with up to 25 Jupiter masses are rather commonly found around stars with about 2 Solar masses. The frequency of detected planetary companions appears to increase with metallicity. No planets or planet candidates are found around stars with more than 2.7 Solar masses, although our sample contains 113 such stars. We conclude that the occurrence rate of giant planets as a function of Stellar mass peaks around 2 Solar masses. This has important consequences for our understanding of giant planet formation.The stars 91 Aqr and tau Gem have companions with orbits that are among those with the lowest eccentricities of all known exoplanets, perhaps due to tidal circularization during the RGB phase. If confirmed, this would be the first evidence of planetary orbits modified through stellar evolution.We have discovered several multiple systems in our sample. An extensive dynamical analysis of the eta Cet system indicates that it contains two massive planets in a 2:1 orbital resonance. The star nu Oph is orbited by two brown dwarf companions in a 6:1 resonance. It is likely that they arrived in this resonance through migration in a circumstellar disk, arguing strongly that objects with more than 20 Jupiter masses can be formed in disks around Herbig Ae stars.

  6. The depths of clouds on Jupiter: Observational constraints on the O/H ratio

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; Bjoraker, Gordon L.; de Pater, Imke; Ádámkovics, Máté

    2015-11-01

    The oxygen abundance in Jupiter is an important constraint on planet formation and conditions in protoplanetary disks. Oxygen, in the form of water, is also dynamically significant in Jupiter's atmosphere: as a tracer of circulation and as a carrier of latent heat.We have developed a technique to spectroscopically measure the depth of opaque cloud tops in Jupiter's atmosphere (Bjoraker et al. 2015, ApJ in press, arXiv:1508.04795). We measure resolved CH3D line shapes in the 5-micron window of Jupiter's spectrum to distinguish between cloud-top pressure levels of about 3 to 10 bars.We will use the retrieved cloud top pressure levels to place lower limits on the deep O/H ratio in Jupiter, based on Keck/NIRSPEC spectra acquired in January 2013. Since our spectra do not directly give the temperature/pressure profile in the cloud layer, constraining the O/H ratio requires independent atmospheric structure data. We will review observational and theoretical constraints on Jupiter's thermal structure, which lead to uncertainty bounds on the O/H ratio we derive. Preliminary work to date suggests that our technique may be able to determine whether or not the Galileo Probe Mass Spectrometer O/H measurement can be representative of the planet's bulk abundance, and whether O is supersolar in Jupiter like the other volatile elements C, N, and S. If we can distinguish between O/H lower limits of 10x and 3x solar, we will be able to test the hypothesis that Jupiter's volatiles must have been delivered via water ice clathrates.[This conference abstract is supported by NASA grant NNX11AM55G issued through the Outer Planets Research Program, and by grants NNX14AJ43G and NNX15AJ41G through the Planetary Astronomy and Solar System Observations Programs.

  7. View of Jupiter

    NASA Technical Reports Server (NTRS)

    1975-01-01

    This view of Jupiter shows the giant planet's cloud tops taken by the Pioneer 10 spacecraft as it flew past Jupiter last December. This view was taken from 2,695,000 kilometers (1,842,451 miles) away. It shows the 25,000 mile long Great Red Spot, which is large enough to swallow up several Earths. Individual cloud formations are visible in some detail. The bright zones appear to become split up into the detailed flow patterns of Jupiter's atmosphere and clouds. The area surrounding the Spot in the bright South Tropical Zone, suggests a flow pattern about the Spot which is bulged toward the north by the Spot. The Spot may be a gigantic 'permanent hurricane.' The gigantic cloud swirls are thousands or more miles across. Pioneer 10 flew past Jupiter in December 1974 and flew past the orbit of Pluto in 1987. A sister spacecraft, Pioneer 11 reached Jupiter in December 1975. The Pioneer Project was managed by NASA's Ames Research Center, Mountain View, Calafornia. The spacecraft was built by TRW Systems.

  8. A Neptune-Mass Planet Orbiting the Nearby M Dwarf GJ 436

    E-print Network

    Paul Butler; Steven S. Vogt; Geoffrey W. Marcy; Debra A. Fischer; Jason T. Wright; Gregory W. Henry; Greg Laughlin; Jack Lissauer

    2004-09-15

    We report precise Doppler measurements of GJ 436 (M2.5V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 d, eccentricity of 0.12 (consistent with zero) and velocity semi-amplitude of $K =18.1$ \\ms. The minimum mass (\\msini) for the planet is 0.067 \\mjup = 1.2 M$_{\\rm NEP}$ = 21 M$_{\\rm EARTH}$, making it the lowest mass exoplanet yet found around a main sequence star and the first candidate in the Neptune mass domain. GJ 436 (Mass = 0.41 \\msune) is only the second M dwarf found to harbor a planet, joining the two--planet system around GJ 876. The low mass of the planet raises questions about its constitution, with possible compositions of primarily H and He gas, ice/rock, or rock--dominated. The implied semi--major axis is $a$ = 0.028 AU = 14 stellar radii, raising issues of planet formation, migration, and tidal coupling with the star. GJ 436 is $>3$ Gyr old, based on both kinematic and chromospheric diagnostics. The star exhibits no photometric variability on the 2.644-day Doppler period to a limiting amplitude of 0.0004 mag, supporting the planetary interpretation of the Doppler periodicity. Photometric transits of the planet across the star are ruled out for gas giant compositions and are also unlikely for solid compositions. As the third closest known planetary system, GJ 436 warrants follow--up observations by high resolution optical and IR

  9. A Moderate Migration Scenario to form the Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Todd, Zoe Robin; Sigurdsson, Steinn

    2015-12-01

    The early solar system contained a gas-dominated protoplanetary disk that could cause the migration of the giant planets. This migration can be in the form of a two-stage migration, including an inward and then outward migration. One of the current favored theories, the Grand Tack theory, states that Jupiter migrates in to 1.5 AU, creating a planetesimal disk truncated at 1 AU to then form the terrestrial planets during the subsequent outward migration of Jupiter. There are reasons to believe that such a large movement by Jupiter may be impractical, namely the disk would need to be massive and long-lived. An exploration of migration parameters that involve smaller migration distances and shorter timescales can shed light on whether such extreme displacements are necessary for the formation of the solar system. We examine more moderate migration simulations, where Jupiter starts near the conjectured location of the ice line and migrates a moderate radial distance inward for a variety of distances and times. After the inward migration, Jupiter moves outwards to its final orbital configuration today. We find that the planetesimal disk need not be truncated at 1 AU to form planets with similar characteristics to those in the solar system. We vary the number and mass of planetesimals in the disk to see how this affects the characteristics of the forming terrestrial planets. We find a number of scenarios that provide systems of terrestrial planets similar to those in the solar system. We thus propose an alternative to the Grand Tack theory where Jupiter’s migration is less extreme than proposed in the Grand Tack theory.

  10. Taxonomy of the extrasolar planet

    E-print Network

    Plávalová, E

    2011-01-01

    When a star is described as a spectral class G2V, we know that the star is similar to our Sun.We know its approximate mass, temperature, age and size. In our work with extrasolar planets database, it is very useful to have a taxonomy scale (classification), for example, like the Harvard classification for stars. This new taxonomy has to be comprehensible and present the important information about extrasolar planets. The important information of extrasolar planets are their mass, radius, period, density, eccentricity, temperature, and their distance from the parent star. There are too many parameters, that is, taxonomy with six parameters would be complicated and difficult to apply. We propose following the extrasolar planet taxonomy scale with only four parameters. The first parameter is the information about the mass of an extrasolar planet in the form of the units of the mass of other known planets, where M - Mercury, E - Earth, N - Neptune, and J - Jupiter. The second parameter is the distance from its pa...

  11. Precision Astrometry of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Unwin, Stephen C.; Traub, W. A.

    2010-05-01

    Exoplanets are now being discovered by a variety of observational techniques, including radial velocity, transits, microlensing and in a few examples, direct imaging. Each technique has distinct advantages and disadvantages, depending on the planet or system parameters of interest. The exoplanet parameter space is very large, and only partially explored. Precision astrometry has yet to contribute significantly, due to the difficulty of achieving the necessary precision from the ground. Space astrometry of exoplanets will begin with Gaia, which will explore Jupiter-mass planet populations. The Space Interferometry Mission (SIM Lite) will provide the precision needed to do a thorough survey of the local neighborhood for planets down to Earth mass, and measure their masses and orbits. In this poster we show how astrometry opens up a critical part of the exoplanet parameter space: low-mass planets around nearby stars. This is of particular significance because these are the planets for which direct imaging and spectroscopy will provide the most detailed understanding of planets that may have Earth-like characteristics.

  12. Extrasolar planets

    PubMed Central

    Lissauer, Jack J.; Marcy, Geoffrey W.; Ida, Shigeru

    2000-01-01

    The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems. PMID:11035782

  13. On Jupiter's inertial mode oscillations

    E-print Network

    Boris Dintrans; Rachid Ouyed

    2001-08-31

    Properties of inertial modes of Jupiter are investigated for an n=1 polytropic description of the planet interior. We use the anelastic approximation to overcome the usual handicap of a severe spherical harmonics truncation. A powerful iterative solver then allows us to compute the frequencies of the most promising low-order modes using as many spherical harmonics as necessary. The induced O(1%) errors of our model are now within observational limits. A plausible seismological model of Jupiter might thus be at hand provided the use of a more realistic description of the planet interior.

  14. Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets

    NASA Astrophysics Data System (ADS)

    Heller, R.; Barnes, R.

    2015-04-01

    The Kepler space telescope has proven capable of detecting transits of objects almost as small as the Earth's Moon. Some studies suggest that moons as small as 0.2 Earth masses can be detected in the Kepler data by transit timing variations and transit duration variations of their host planets. If such massive moons exist around giant planets in the stellar habitable zone (HZ), then they could serve as habitats for extraterrestrial life. While earlier studies on exomoon habitability assumed the host planet to be in thermal equilibrium with the absorbed stellar flux, we here extend this concept by including the planetary luminosity from evolutionary shrinking. Our aim is to assess the danger of exomoons to be in a runaway greenhouse state due to extensive heating from the planet. We apply pre-computed evolution tracks for giant planets to calculate the incident planetary radiation on the moon as a function of time. Added to the stellar flux, the total illumination yields constraints on a moon's habitability. Ultimately, we include tidal heating to evaluate a moon's energy budget. We use a semi-analytical formula to parameterize the critical flux for the moon to experience a runaway greenhouse effect. Planetary illumination from a 13-Jupiter-mass planet onto an Earth-sized moon at a distance of ten Jupiter radii can drive a runaway greenhouse state on the moon for about 200 million years (Myr). When stellar illumination equivalent to that received by Earth from the Sun is added, then the runaway greenhouse holds for about 500 Myr. After 1000 Myr, the planet's habitable edge has moved inward to about six Jupiter radii. Exomoons in orbits with eccentricities of 0.1 experience strong tidal heating; they must orbit a 13-Jupiter-mass host beyond 29 or 18 Jupiter radii after 100 Myr (at the inner and outer boundaries of the stellar HZ, respectively), and beyond 13 Jupiter radii (in both cases) after 1000 Myr to be habitable. If a roughly Earth-sized, Earth-mass moon would be detected in orbit around a giant planet, and if the planet-moon duet would orbit in the stellar HZ, then it will be crucial to recover the orbital history of the moon. If, for example, such a moon around a 13-Jupiter-mass planet has been closer than 20 Jupiter radii to its host during the first few hundred million years at least, then it might have lost substantial amounts of its initial water reservoir and be uninhabitable today.

  15. Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass Stars

    E-print Network

    Ciesla, Fred J; Pascucci, Ilaria; Apai, Daniel

    2015-01-01

    Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our Solar System. Here we suggest that the water content of primitive bodies in many planetary systems may actually be much higher, as carbonaceous chondrites have lost some of their original water due to heating from short-lived radioisotopes that drove parent body alteration. Using N-body simulations, we explore how planetary accretion would be different if bodies beyond the water line contained a water mass fraction consistent with chemical equilibrium calculations, and more similar to comets, as opposed to the more traditional water-depleted values. We apply this model to consider planet formation around stars of different masses and identify trends in the properties of Habitable Zone planets and planetary system architecture which could be tested by ongoing exoplanet census data collection. Comparison of such data with the model predicted tren...

  16. The fate of scattered planets

    SciTech Connect

    Bromley, Benjamin C.; Kenyon, Scott J. E-mail: skenyon@cfa.harvard.edu

    2014-12-01

    As gas giant planets evolve, they may scatter other planets far from their original orbits to produce hot Jupiters or rogue planets that are not gravitationally bound to any star. Here, we consider planets cast out to large orbital distances on eccentric, bound orbits through a gaseous disk. With simple numerical models, we show that super-Earths can interact with the gas through dynamical friction to settle in the remote outer regions of a planetary system. Outcomes depend on planet mass, the initial scattered orbit, and the evolution of the time-dependent disk. Efficient orbital damping by dynamical friction requires planets at least as massive as the Earth. More massive, longer-lived disks damp eccentricities more efficiently than less massive, short-lived ones. Transition disks with an expanding inner cavity can circularize orbits at larger distances than disks that experience a global (homologous) decay in surface density. Thus, orbits of remote planets may reveal the evolutionary history of their primordial gas disks. A remote planet with an orbital distance ?100 AU from the Sun is plausible and might explain correlations in the orbital parameters of several distant trans-Neptunian objects.

  17. KEPLER-6b: A TRANSITING HOT JUPITER ORBITING A METAL-RICH STAR

    SciTech Connect

    Dunham, Edward W.; Borucki, William J.; Koch, David G.; Lissauer, Jack J.; Batalha, Natalie M.; Buchhave, Lars A.; Furesz, Gabor; Geary, John C.; Latham, David W.; Brown, Timothy M.; Caldwell, Douglas A.; Jenkins, Jon M.; Cochran, William D.; Endl, Michael; Fischer, Debra; Gautier, Thomas N.; Gould, Alan; Howell, Steve B.; Kjeldsen, Hans

    2010-04-20

    We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H]= +0.34{+-}0.04. The planet's mass is about 2/3 that of Jupiter, M {sub P} = 0.67 M {sub J}, and the radius is 30% larger than that of Jupiter, R {sub P} = 1.32 R {sub J}, resulting in a density of {rho}{sub P} = 0.35 g cm{sup -3}, a fairly typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, M {sub *} = 1.21 M {sub sun}, and larger than the Sun, R {sub *} = 1.39 R {sub sun}.

  18. Predictions for the frequency and orbital radii of massive extrasolar planets

    E-print Network

    Philip J. Armitage; Mario Livio; S. H. Lubow; J. E. Pringle

    2002-03-29

    We investigate the migration of massive extrasolar planets due to gravitational interaction with a viscous protoplanetary disc. We show that a model in which planets form at 5 AU at a constant rate, before migrating, leads to a predicted distribution of planets that is a steeply rising function of log (a), where a is the orbital radius. Between 1 AU and 3 AU, the expected number of planets per logarithmic interval in orbital radius roughly doubles. We demonstrate that, once selection effects are accounted for, this is consistent with current data, and then extrapolate the observed planet fraction to masses and radii that are inaccessible to current observations. In total, about 15 percent of stars targeted by existing radial velocity searches are predicted to possess planets with masses 0.3 M_Jupiter planets (around 5 percent of the target stars) lie at the radii most amenable to detection via microlensing. A further 5-10 percent of stars could have planets at radii of 5 AU planet does not occur. About 10-15 percent of systems with a surviving massive planet are estimated to fall into this class. Finally, we note that a smaller fraction of low mass planets than high mass planets is expected to survive without being consumed by the star. The initial mass function for planets is thus predicted to rise more steeply towards small masses than the observed mass function.

  19. Hot Neptunes - a Key to Giant Planet Formation

    NASA Astrophysics Data System (ADS)

    Wuchterl, G.

    A hot Neptune is a hypothetical giant planet in an orbit close to its star (typically less than 1 AU) that has core and envelope masses similar to Uranus and Neptune. As a consequence the core mass is supercritical (typically 10 earth masses) and the hydrogen and helium envelope-mass is per definition relatively small (typically an earth mass). Because the core mass is supercritical, quasi-hydrostatic giant planet formation models predict envelope growth to large masses, if nebula gas is present. Hence a proto Neptune should accrete gas and rapidly grow to masses comparable to Jupiter's mass under such conditions. On the other hand, some formation models for Vulcans -- that are also called hot Jupiters, like 51 Pegasi b or HD 209458 b -- invoke orbital migration to transfer giant planets from their formation regions, beyond the snow-line, say, to their ultimately small orbital radii, after they accumulated their massive envelopes. A necessary condition for the required type-I/II migration to operate, is the presence of a significant nebula disk. Hence if planets migrate, they do so in the presence of a disk of considerable mass. In that case, they are expected to grow the large, Jupiter-mass envelopes that correspond to their supercritical cores. If migration is important in the formation of Vulcans they are expected to have large envelopes. Hence I argue that the detection of a Hot Neptune would refute migration models for the formation of hot giant planets and is a critical observation to decide between migration models and in-situ formation models. The latter explain low-mass gaseous envelopes and Uranus/Neptune-like giant planets by a hydrodynamical accretion instability that limits the envelope mass.

  20. HST hot Jupiter transmission spectral survey: The atmospheric circulation of a large hot Jupiter sample

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David K.; Lewis, Nikole K.; Fortney, Jonathan J.; Marley, Mark S.; Showman, Adam P.

    2015-11-01

    Even as we move towards characterizing smaller and cooler exoplanets, hot Jupiters continue to be the best transiting planets for probing the atmospheric properties of exoplanets and refining current theory. Here we present results from a comprehensive atmospheric circulation study of nine transiting hot Jupiters that probe a wide range of planetary properties, including orbital distance, rotation rate, mass, radius, gravity and stellar insolation. We utilize these circulation models to aid in the interpretation of transmission spectra obtained using the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) as a part of a large Hubble Space Telescope (HST) transmission spectral survey. These observations have shown a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. Our “grid” of models recovers trends shown in other parametric studies of hot Jupiters, particularly increased day-night temperature contrast with increasing equilibrium temperature and equatorial superrotation. Furthermore, we show that three-dimensional variations in temperature, particularly across the western and eastern terminators and from the equator to the pole, can vary by hundreds of Kelvin. This can result in vastly different cloud properties across the limb, which can lead to variations in transmission spectra. Finally, we comment on prospects with the James Webb Space Telescope (JWST) to further characterize hot Jupiters out to longer wavelengths.

  1. HST hot Jupiter transmission spectral survey: The atmospheric circulation of a large hot Jupiter sample

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David Kent; Lewis, Nikole K.; Fortney, Jonathan; Marley, Mark; Showman, Adam P.

    2015-12-01

    Even as we move towards characterizing smaller and cooler exoplanets, hot Jupiters continue to be the best transiting planets for probing the atmospheric properties of exoplanets and refining current theory. Here we present results from a comprehensive atmospheric circulation study of nine transiting hot Jupiters that probe a wide range of planetary properties, including orbital distance, rotation rate, mass, radius, gravity and stellar insolation. We utilize these circulation models to aid in the interpretation of transmission spectra obtained using the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) as a part of a large Hubble Space Telescope (HST) transmission spectral survey. These observations have shown a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. Our “grid” of models recovers trends shown in other parametric studies of hot Jupiters, particularly increased day-night temperature contrast with increasing equilibrium temperature and equatorial superrotation. Furthermore, we show that three-dimensional variations in temperature, particularly across the western and eastern terminators and from the equator to the pole, can vary by hundreds of Kelvin. This can result in vastly different cloud properties across the limb, which can lead to variations in transmission spectra. Finally, we comment on prospects with the James Webb Space Telescope (JWST) to further characterize hot Jupiters out to longer wavelengths.

  2. A giant cloud of hydrogen escaping the warm Neptune-mass planet GJ 436b

    NASA Astrophysics Data System (ADS)

    Ehrenreich, David

    2015-12-01

    Exoplanets in extreme irradiation environments, close to their parent stars, could lose some fraction of their atmospheres because of the extreme irradiation. Atmospheric mass loss has been observed during the past 12 years for hot gas giants, as large (~10%) ultraviolet absorption signals during transits. Meanwhile, no confident detection have been obtained for lower-mass planets, which are most likely to be significantly affected by atmospheric escape. In fact, hot rocky planets observed by Corot and Kepler might have lost all of their atmosphere, having begun as Neptune-like. The signature of this loss could be observed in the ultraviolet, when the planet and its escaping atmosphere transit the star, giving rise to deeper and longer transit signatures than in the optical. I will report on new Hubble observations of the Neptune-mass exoplanet GJ 436b, around which an extended atmosphere has been tentatively detected in 2014. The new data reveal that GJ 436b has huge transit depths of 56.3±3.5% in the hydrogen Lyman-alpha line, far beyond the 0.69% optical transit depth, and even far beyond mass loss signatures observed at the same wavelength from more irradiated gas giants. We infer from this repeated observations that the planet is surrounded and trailed by a large exospheric cloud of hydrogen, shaped as a giant comet, much bigger than the star. We estimate a mass-loss rate, which today is far too small to deplete the atmosphere of a Neptune-like planet in the lifetime of the parent star, but would have been much greater in the past. This 16-sigma detection opens exciting perspectives for the atmospheric characterization of low-mass and moderately-irradiated exoplanets, a large number of which will be detected by forthcoming transit surveys.

  3. Tidal Effects of Passing Planets and Mass Extinctions

    E-print Network

    Daniele Fargion; Arnon Dar

    1998-02-20

    Recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their passage near Earth could have generated gigantic tidal waves, large volcanic eruptions, sea regressions, large meteoritic impacts and drastic changes in global climate. They could have caused the major biological mass extinctions in the past 600 My as documented in the geological records.

  4. CONVECTION AND GIANT PLANET FORMATION Mixing length convection reduces the critical mass

    E-print Network

    Wuchterl, Günther

    CONVECTION AND GIANT PLANET FORMATION Mixing length convection reduces the critical mass G zero entropy gradient convection. That means that convection is assumed to be very efficient and radiative losses from eddies are neglected. The tem­ perature gradient in convectively unstable regions

  5. ExtraSolar Planets Finding Extrasolar Planets. I

    E-print Network

    Walter, Frederick M.

    ExtraSolar Planets #12;Finding Extrasolar Planets. I Direct Searches Direct searches are difficult #12;Finding Extrasolar Planets. II Transits #12;Transits Transits requires an edge-on orbit. ·Jupiter;How Transits Work #12;Finding Extrasolar Planets. III Astrometric Wobble #12;Finding Extrasolar

  6. Post-GAIA astrometry with JWST AMI for planet masses around nearby M dwarfs

    NASA Astrophysics Data System (ADS)

    Greenbaum, Alexandra; Thatte, Deepashri G.; Artigau, Etienne; Sivaramakrishnan, Anand; Martel, Andre

    2016-01-01

    Obtaining the mass for young planets is an important test of giant planet evolution theories. The combination of direct imaging and radial velocity or astrometric monitoring can provide a direct measurement of both planet mass and photometry. The Near-IR Imager and Slitless Spectrograph (NIRISS) on the the James Webb Space Telescope (JWST) will contain a 7-hole non-redundant mask in its pupil that will provide interferometric resolution with good dynamic range. NIRISS aperture masking interferometry (AMI) will provide an order of magnitude better contrast than ground-based aperture masking and be able to observe stars a few orders of magnitude fainter than from the ground. This will enable the detection of young jovian planets at the highest resolution available to JWST at the near-IR wavelengths to follow up GAIA planet detections around nearby M dwarfs within 30pc. Using an analytic model of the AMI PSF we measure the astrometric precision with NIRISS. I will present recent NIRISS cryo-vacuum tests and provide an estimate for astrometric precision with AMI.

  7. Interior phase transformations and mass-radius relationships of silicon-carbon planets

    SciTech Connect

    Wilson, Hugh F.; Militzer, Burkhard

    2014-09-20

    Planets such as 55 Cancri e orbiting stars with a high carbon-to-oxygen ratio may consist primarily of silicon and carbon, with successive layers of carbon, silicon carbide, and iron. The behavior of silicon-carbon materials at the extreme pressures prevalent in planetary interiors, however, has not yet been sufficiently understood. In this work, we use simulations based on density functional theory to determine high-pressure phase transitions in the silicon-carbon system, including the prediction of new stable compounds with Si{sub 2}C and SiC{sub 2} stoichiometry at high pressures. We compute equations of state for these silicon-carbon compounds as a function of pressure, and hence derive interior structural models and mass-radius relationships for planets composed of silicon and carbon. Notably, we predict a substantially smaller radius for SiC planets than in previous models, and find that mass radius relationships for SiC planets are indistinguishable from those of silicate planets. We also compute a new equation of state for iron. We rederive interior models for 55 Cancri e and are able to place more stringent restrictions on its composition.

  8. Convection and Mixing in Giant Planet Evolution

    E-print Network

    Vazan, Allona; Kovetz, Attay; Podolak, Morris

    2015-01-01

    The primordial internal structures of gas giant planets are unknown. Often giant planets are modeled under the assumption that they are adiabatic, convective, and homogeneously mixed, but this is not necessarily correct. In this work, we present the first self-consistent calculation of convective transport of both heat and material as the planets evolve. We examine how planetary evolution depends on the initial composition and its distribution, whether the internal structure changes with time, and if so, how it affects the evolution. We consider various primordial distributions, different compositions, and different mixing efficiencies and follow the distribution of heavy elements in a Jupiter-mass planet as it evolves. We show that a heavy-element core cannot be eroded by convection if there is a sharp compositional change at the core-envelope boundary. If the heavy elements are initially distributed within the planet according to some compositional gradient, mixing occurs in the outer regions resulting in a...

  9. Spitzer Secondary Eclipse Observations of Five Cool Gas Giant Planets and Empirical Trends in Cool Planet Emission Spectra

    NASA Astrophysics Data System (ADS)

    Kammer, Joshua A.; Knutson, Heather A.; Line, Michael R.; Fortney, Jonathan J.; Deming, Drake; Burrows, Adam; Cowan, Nicolas B.; Triaud, Amaury H. M. J.; Agol, Eric; Desert, Jean-Michel; Fulton, Benjamin J.; Howard, Andrew W.; Laughlin, Gregory P.; Lewis, Nikole K.; Morley, Caroline V.; Moses, Julianne I.; Showman, Adam P.; Todorov, Kamen O.

    2015-09-01

    In this work we present Spitzer 3.6 and 4.5 ?m secondary eclipse observations of five new cool (\\lt 1200 K) transiting gas giant planets: HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured eclipse depths to the predictions of a suite of atmosphere models and to eclipse depths for planets with previously published observations in order to constrain the temperature- and mass-dependent properties of gas giant planet atmospheres. We find that the dayside emission spectra of planets less massive than Jupiter require models with efficient circulation of energy to the night side and/or increased albedos, while those with masses greater than that of Jupiter are consistently best-matched by models with inefficient circulation and low albedos. At these relatively low temperatures we expect the atmospheric CH4/CO ratio to vary as a function of metallicity, and we therefore use our observations of these planets to constrain their atmospheric metallicities. We find that the most massive planets have dayside emission spectra that are best-matched by solar metallicity atmosphere models, but we are not able to place strong constraints on metallicities of the smaller planets in our sample. Interestingly, we find that the ratio of the 3.6 and 4.5 ?m brightness temperatures for these cool transiting planets is independent of planet temperature, and instead exhibits a tentative correlation with planet mass. If this trend can be confirmed, it would suggest that the shape of these planets’ emission spectra depends primarily on their masses, consistent with the hypothesis that lower-mass planets are more likely to have metal-rich atmospheres.

  10. Detection of a NEPTUNE-mass planet in the $?^{1}$ Cancri system using the Hobby-Eberly Telescope

    E-print Network

    Barbara E. McArthur; Michael Endl; William D. Cochran; G. Fritz Benedict; Debra A. Fischer; Geoffrey W. Marcy; R. Paul Butler; Dominique Naef; Michel Mayor; Diedre Queloz; Stephane Udry; Thomas E. Harrison

    2004-08-31

    We report the detection of the lowest mass extra-solar planet yet found around a Sun-like star - a planet with an \\msini of only 14.21 $\\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\\rho^{1}$ Cancri, a planetary system which already has three known planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner planet at 0.04 AU. We estimate an inclination of the outer planet $\\rho^{1}$ Cancri d, based upon {\\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner planet of only 17.7 $\\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.

  11. Solubility of iron in metallic hydrogen and stability of dense cores in giant planets

    E-print Network

    Militzer, Burkhard

    , Hugh F. Wilson1,2 and Burkhard Militzer1 swahl@berkeley.edu Department of Earth and Planetary Science. 2012; Militzer 2013; Wilson & Militzer 2010), knowledge of the deep interior structure of giant planets mass of 0-10 (Guillot 2005) and 14-18 (Militzer et al. 2008) Earth masses for Jupiter, and 9

  12. Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings

    E-print Network

    Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings Carolyn C. Porco,1 * Robert A. West Science Subsystem acquired about 26,000 images of the Jupiter system as the spacecraft encountered the giant planet en route to Saturn. We report findings on Jupiter's zonal winds, convective storms, low

  13. Jupiter: Giant of the solar system. [its solar orbits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

  14. MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU

    SciTech Connect

    Hansen, Brad M. S.; Murray, Norm

    2012-06-01

    We demonstrate that the observed distribution of 'hot Neptune'/'super-Earth' systems is well reproduced by a model in which planet assembly occurs in situ, with no significant migration post-assembly. This is achieved only if the amount of mass in rocky material is {approx}50-100 M{sub Circled-Plus} interior to 1 AU. Such a reservoir of material implies that significant radial migration of solid material takes place, and that it occurs before the stage of final planet assembly. The model not only reproduces the general distribution of mass versus period but also the detailed statistics of multiple planet systems in the sample. We furthermore demonstrate that cores of this size are also likely to meet the criterion to gravitationally capture gas from the nebula, although accretion is rapidly limited by the opening of gaps in the gas disk. If the mass growth is limited by this tidal truncation, then the scenario sketched here naturally produces Neptune-mass objects with substantial components of both rock and gas, as is observed. The quantitative expectations of this scenario are that most planets in the 'hot Neptune/super-Earth' class inhabit multiple-planet systems, with characteristic orbital spacings. The model also provides a natural division into gas-rich (hot Neptune) and gas-poor (super-Earth) classes at fixed period. The dividing mass ranges from {approx}3 M{sub Circled-Plus} at 10 day orbital periods to {approx}10 M{sub Circled-Plus} at 100 day orbital periods. For orbital periods <10 days, the division is less clear because a gas atmosphere may be significantly eroded by stellar radiation.

  15. Kepler-424 b: A 'lonely' hot Jupiter that found A companion

    SciTech Connect

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Havel, Mathieu; Howell, Steve B.; Quintana, Elisa; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Lucas, Phillip; Fischer, Debra; Ciardi, David R.

    2014-11-10

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be {sup l}onely{sup .} This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to ? Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M {sub ?}.

  16. Kepler-424 b: A "Lonely" Hot Jupiter that Found a Companion

    NASA Astrophysics Data System (ADS)

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Havel, Mathieu; Lucas, Phillip; Howell, Steve B.; Fischer, Debra; Quintana, Elisa; Ciardi, David R.

    2014-11-01

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be "lonely". This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to \\upsilon Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M ?. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  17. Measuring the Mass of Free-Floating Planets with K2

    NASA Astrophysics Data System (ADS)

    Penny, Matthew

    2015-12-01

    Campaign 9 of the K2 mission (K2C9) will begin April next year, and presents us with our first and likely only opportunity to measure the masses of the large population of free-floating planets found by gravitational microlensing surveys. I will describe the plans for the campaign, including the unprecedented need for wide-field ground-based observations, and the innovative techniques that are being developed to work in crowded fields with Kepler's large pixels. Finally I will discuss what we can expect to learn from K2C9 and future microlensing surveys for free-floating planets.

  18. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie Anne; Ford, Eric B.

    2015-08-01

    The Kepler Mission has discovered thousands of super-Earths, paving the way for the first statistical studies of the dynamics, formation, and evolution of these planets. Planetary masses are an important physical property that these studies consider, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern for these studies is therefore how to map the measured radii to mass estimates, in this regime of planetary sizes where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters given the data. We analyze how the details depend on the radius range of the sample, and on the method used to provide the mass measurements. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/M_Earth = 2.7 (R/R_Earth)^1.2 and a scatter in mass of 1.7 M_Earth is the "best-fit" probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes.

  19. Finding the Youngest Planets

    NASA Astrophysics Data System (ADS)

    Crockett, C. J.; Mahmud, N.; Prato, L.; Johns-Krull, C. M.; Hartigan, P.; Jaffe, D. T.; Beichman, C. A.

    2011-12-01

    We are conducting a multiwavelength radial velocity (RV) survey of the Taurus-Auriga low-mass star forming region. The goal of this survey is to characterize the hot Jupiter population around a sample of 1-3 Myr old classical and weak-lined T Tauri stars. Given the young ages of these targets, a positive detection will help identify the planet formation timescale. The presence of large, cool star spots makes this a challenging environment in which to conduct an RV survey. To distinguish between spot-induced RV variability and true companions, we observe all of our targets in both visible light and K band: spot-induced RV variability exhibits a wavelength dependence that companion-induced variability does not. We present details on our methodology and analysis of several planet candidate targets.

  20. Extreme Planet-Like Systems: Brown Dwarfs at the Exoplanet Mass Boundary

    NASA Astrophysics Data System (ADS)

    Faherty, Jacqueline Kelly

    2015-12-01

    Brown dwarfs have long been the observational anchors for our theoretical understanding of giant gas planets. Recent studies have uncovered a population of nearby young sources that rival the age and mass of many planetary mass companions. From detailed observations, we postulate that objects in this young population have dynamic atmospheres ripe with exotic, thick condensate cloud species that drive extreme photometric and spectroscopic characteristics. In this talk I will review how we are using these so-called exoplanet analogs to establish luminosity, temperature, age, and mass relations for brown dwarf into planetary mass objects.

  1. EVIDENCE FOR THE TIDAL DESTRUCTION OF HOT JUPITERS BY SUBGIANT STARS

    SciTech Connect

    Schlaufman, Kevin C.; Winn, Joshua N. E-mail: jwinn@mit.edu

    2013-08-01

    Tidal transfer of angular momentum is expected to cause hot Jupiters to spiral into their host stars. Although the timescale for orbital decay is very uncertain, it should be faster for systems with larger and more evolved stars. Indeed, it is well established that hot Jupiters are found less frequently around subgiant stars than around main-sequence stars. However, the interpretation of this finding has been ambiguous, because the subgiants are also thought to be more massive than the F- and G-type stars that dominate the main-sequence sample. Consequently, it has been unclear whether the absence of hot Jupiters is due to tidal destruction or inhibited formation of those planets around massive stars. Here we show that the Galactic space motions of the planet-hosting subgiant stars demand that on average they be similar in mass to the planet-hosting main-sequence F- and G-type stars. Therefore the two samples are likely to differ only in age, and provide a glimpse of the same exoplanet population both before and after tidal evolution. As a result, the lack of hot Jupiters orbiting subgiants is clear evidence for their tidal destruction. Questions remain, though, about the interpretation of other reported differences between the planet populations around subgiants and main-sequence stars, such as their period and eccentricity distributions and overall occurrence rates.

  2. Terrestrials Dwarf Planets

    E-print Network

    Gaudi, B. Scott

    Terrestrials Gas Giants Ice Giants Dwarf Planets The Solar System #12;Neptune Uranus Saturn Jupiter Density: 3900 ­ 5500 kg m-3 #12;Jupiter 318 ME 5.2 AU Uranus 15 ME 19.6 AUSaturn 95 ME 9.5 AU Neptune 17 3.88 RE Uranus Neptune Uranus and Neptune are Ice Giants made mostly of ices with thin Hydrogen

  3. EXTRASOLAR PLANETS Awhiffofmethane

    E-print Network

    - pheres in our Solar System: those of Earth, Mars, Titan and the gas giants, Jupiter, Saturn, Uranus our Solar System. It was made possible by the fact that HD 189733b is a transiting planet -- one whose us about planetary behaviour? The methane abun- dances on Jupiter, Saturn and both Uranus and Neptune

  4. Super-massive planets around late-type stars—the case of OGLE-2012-BLG-0406Lb

    SciTech Connect

    Poleski, Rados?aw; Gould, Andrew; Udalski, Andrzej; Szyma?ski, Micha? K.; Soszy?ski, Igor; Kubiak, Marcin; Pietrzy?ski, Grzegorz; Koz?owski, Szymon; Pietrukowicz, Pawe?; Ulaczyk, Krzysztof; Skowron, Jan; Wyrzykowski, ?ukasz; Dong, Subo

    2014-02-10

    Super-Jupiter-mass planets should form only beyond the snow line of host stars. However, the core accretion theory of planetary formation does not predict super-Jupiters forming around low-mass hosts. We present a discovery of a 3.9 ± 1.2 M {sub Jup} mass planet orbiting the 0.59 ± 0.17 M {sub ?} star using the gravitational microlensing method. During the event, the projected separation of the planet and the star is 3.9 ± 1.0 AU, i.e., the planet is significantly further from the host star than the snow line. This is the fourth such planet discovered using the microlensing technique and challenges the core accretion theory.

  5. Extrasolar planet taxonomy: a new statistical approach

    E-print Network

    Simone Marchi

    2007-05-07

    In this paper we present the guidelines for an extrasolar planet taxonomy. The discovery of an increasing number of extrasolar planets showing a vast variety of planetary parameters, like Keplerian orbital elements and environmental parameters, like stellar masses, spectral types, metallicity etc., prompts the development of a planetary taxonomy. In this work via principal component analysis followed by hierarchical clustering analysis, we report the definition of five robust groups of planets. We also discuss the physical relevance of such analysis, which may provide a valid basis for disentangling the role of the several physical parameters involved in the processes of planet formation and subsequent evolution. For instance, we were able to divide the hot Jupiters into two main groups on the basis of their stellar masses and metallicities. Moreover, for some groups, we find strong correlations between metallicity, semi-major axis and eccentricity. The implications of these findings are discussed.

  6. A Three-dimensional Non-spherical Calculation Of The Rotationally Distorted Shape And Internal Structure Of A Model Of Jupiter With A Polytropic Index Of Unity

    NASA Astrophysics Data System (ADS)

    Zhang, Keke; Kong, D.; Schubert, G.; Anderson, J.

    2012-10-01

    An accurate calculation of the rotationally distorted shape and internal structure of Jupiter is required to understand the high-precision gravitational field that will be measured by the Juno spacecraft now on its way to Jupiter. We present a three-dimensional non-spherical numerical calculation of the shape and internal structure of a model of Jupiter with a polytropic index of unity. The calculation is based on a finite element method and accounts for the full effects of rotation. After validating the numerical approach against the asymptotic solution of Chandrasekhar (1933) that is valid only for a slowly rotating gaseous planet, we apply it to a model of Jupiter whose rapid rotation causes a significant departure from spherical geometry. The two-dimensional distribution of the density and the pressure within Jupiter is then determined via a hybrid inverse approach by matching the a priori unknown coefficient in the equation of state to the observed shape of Jupiter. After obtaining the two-dimensional distribution of Jupiter's density, we then compute the zonal gravity coefficients and the total mass from the non-spherical Jupiter model that takes full account of rotation-induced shape changes. Our non-spherical model with a polytrope of unit index is able to produce the known mass and zonal gravitational coefficients of Jupiter. Chandrasekhar, S. 1933, The equilibrium of distorted polytropes, MNRAS 93, 390

  7. Formation of planets by tidal downsizing of giant planet embryos

    E-print Network

    Nayakshin, Sergei

    2010-01-01

    We hypothesise that planets are made by tidal downsizing of migrating giant planet embryos. The proposed scheme for planet formation consists of these steps: (i) a massive young protoplanetary disc fragments at R ~ several tens to hundreds of AU on gaseous clumps with masses of a few Jupiter masses; (ii) the clumps cool and contract, and simultaneously migrate closer in to the parent star; (iii) as earlier suggested by Boss (1998), dust sediments inside the gas clumps to form terrestrial mass solid cores; (iv) if the solid core becomes more massive than ~ 10 Earth masses, a massive gas atmosphere collapses onto the solid core; (v) when the gas clumps reach the inner few AU from the star, tidal shear and evaporation due to stellar irradiation peel off the outer metal-poor envelope of the clump. If tidal disruption occurs quickly, while the system is still in stage (iii), a terrestrial planet core is left. If it happens later, in stage (iv), a metal rich gas giant planet with a solid core emerges from the envel...

  8. Ten Multi-planet Systems from K2 Campaigns 1 & 2 and the Masses of Two Hot Super-Earths

    E-print Network

    Sinukoff, Evan; Petigura, Erik A; Schlieder, Joshua E; Crossfield, Ian J M; Ciardi, David R; Fulton, Benjamin J; Isaacson, Howard; Aller, Kimberly M; Baranec, Christoph; Beichman, Charles A; Hansen, Brad M S; Knutson, Heather A; Law, Nicholas M; Liu, Michael C; Riddle, Reed

    2015-01-01

    We present a catalog of 10 multi-planet systems from Campaigns 1 and 2 of the K2 mission. We report the sizes and orbits of 24 planets split between six 2-planet systems and four 3-planet systems. These planets stem from a systematic search of the K2 photometry for all dwarf stars observed by K2 in these fields. We precisely characterized the host stars with adaptive optics imaging and analysis of high-resolution optical spectra from Keck/HIRES and medium-resolution spectra from IRTF/SpeX. The planets are mostly smaller than Neptune (19/24 planets) as in the Kepler mission and all have short periods ($P period super-Earth with a radius of $1.55 \\pm 0.16~R_\\oplus$, a mass of $12.0 \\pm ...

  9. On the minimum core mass for giant planet formation at wide separations

    SciTech Connect

    Piso, Ana-Maria A.; Youdin, Andrew N.

    2014-05-01

    In the core accretion hypothesis, giant planets form by gas accretion onto solid protoplanetary cores. The minimum (or critical) core mass to form a gas giant is typically quoted as 10 M {sub ?}. The actual value depends on several factors: the location in the protoplanetary disk, atmospheric opacity, and the accretion rate of solids. Motivated by ongoing direct imaging searches for giant planets, this study investigates core mass requirements in the outer disk. To determine the fastest allowed rates of gas accretion, we consider solid cores that no longer accrete planetesimals, as this would heat the gaseous envelope. Our spherical, two-layer atmospheric cooling model includes an inner convective region and an outer radiative zone that matches onto the disk. We determine the minimum core mass for a giant planet to form within a typical disk lifetime of 3 Myr. The minimum core mass declines with disk radius, from ?8.5 M {sub ?} at 5 AU to ?3.5 M {sub ?} at 100 AU, with standard interstellar grain opacities. Lower temperatures in the outer disk explain this trend, while variations in disk density are less influential. At all distances, a lower dust opacity or higher mean molecular weight reduces the critical core mass. Our non-self-gravitating, analytic cooling model reveals that self-gravity significantly affects early atmospheric evolution, starting when the atmosphere is only ?10% as massive as the core.

  10. The survival of gas giant planets on wide orbits

    NASA Astrophysics Data System (ADS)

    Stamatellos, Dimitris

    2015-12-01

    It is not known whether gas giant planets on wide orbits form the same way as Jupiter or by fragmentation of gravitationally unstable discs. It has been suggested that giant planets that form on wide orbits in gravitationally unstable discs quickly migrate towards the central star. We simulate the migration of such planets including the effects of gas accretion onto the planet and radiative feedback from the planet, both of which have been ignored in previous studies. We show that a giant planet, which has formed in the outer regions of a protostellar disc, initially migrates towards the central star while accreting gas from the disc. However, the planet eventually opens up a gap in the disc and the migration is essentially halted. At the same time, accretion-powered radiative feedback from the planet, significantly limits its mass growth, keeping it within the planetary mass regime (i.e. below the deuterium burning limit). Giant planets are therefore able to survive as planets (not higher-mass objects, i.e. brown dwarfs) on wide orbits, shaping the environment in which terrestrial planets that may harbour life form.

  11. Voyager to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Voyager mission to explore planets of the outer solar system is summarized. The mission schedule and profiles for encounters with Jupiter and Saturn, and possibly with Uranus and Pluto are included along with a description of the spacecraft and its trajectories. Scientific investigations to be made and the instruments carried are also discussed.

  12. The Relation Between Radius, Mass, and Incident Flux of Exoplanets

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, G. W.; Rowe, J.; Isaacson, H. T.; Howard, A.; Fortney, J. J.; Miller, N.; Demory, B.; Fischer, D.; Adams, E. A.; Dupree, A. K.; Howell, S. B.; Horch, E.; Everett, M. E.; Seager, S.; Fabrycky, D. C.

    2013-01-01

    We measure the mass of a modestly irradiated giant or "warm Jupiter," KOI-94d, in order to calculate its density. We wish to determine whether this planet, which is in a 22 day orbit and receives 107 times as much incident flux as the Earth, is bloated like "hot Jupiters" or as dense as our own Jupiter. In addition to its warm Jupiter, KOI-94 hosts at least 3 smaller planets, all of which were detected through transits by the Kepler Mission. This presents the opportunity to characterize a multi-planet system and to test dynamic stability and formation theory through observations of the masses and orbital elements of these planets. With 26 radial velocity measurements of KOI-94 from the W. M. Keck Observatory/HIRES, we measure the mass of the giant planet and upper limits to the masses of the three smaller planets. Transit timing variations will allow us to hone the mass measurements of the three smaller planets. Using the KOI-94 system and all other planets with published values for both mass and radius, we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to ten Jupiter masses: log(Rp/RE) = 0.007 + 0.53 log(M/ME) - 0.001 log(F/[erg/s/cm^2]) for Mp < 150ME; log(Rp/RE) = 0.67 - 0.036 log(M/ME) + 0.06 log(F/[erg/s/cm^2]) for Mp > 150ME. We also solve these planes in density-mass-flux space: log(?p/[g/cm^3]) = 0.69 - 0.57 log(M/ME) + 0.02 log(F/[erg/s/cm^2]) for Mp < 150ME; log(?p/[g/cm^3]) = -1.23 + 1.10 log(M/ME) - 0.18 log(F/[erg/s/cm^2]) for Mp > 150ME.

  13. Jupiter Eruptions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This visible-light image is from NASA's Hubble Space Telescope taken on May 11, 2007. It shows the turbulent pattern generated by the two plumes on the upper left part of Jupiter.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vi gorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  14. Planets around Low-mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Tamura, Motohide

    2015-01-01

    We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (gsim1 M Jup) around 122 newly identified nearby (lsim40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M ?) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M Jup at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M Jup; L0+2-1; 120 ± 20 AU), GJ 3629 B (64+30-23 M Jup; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M Jup; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M Jup; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M Jup planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M Jup range like those orbiting HR 8799 and ? Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M Jup) companions to single M dwarfs between 10-100 AU is 2.8+2.4-1.5%. Altogether we find that giant planets, especially massive ones, are rare in the outskirts of M dwarf planetary systems. Although the first directly imaged planets were found around massive stars, there is currently no statistical evidence for a trend of giant planet frequency with stellar host mass at large separations as predicted by the disk instability model of giant planet formation. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. This work was also based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  15. PLANETS AROUND LOW-MASS STARS (PALMS). IV. THE OUTER ARCHITECTURE OF M DWARF PLANETARY SYSTEMS

    SciTech Connect

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Tamura, Motohide

    2015-01-01

    We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (?1 M {sub Jup}) around 122 newly identified nearby (?40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M {sub ?}) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M {sub Jup} at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M {sub Jup}; L0{sub ?1}{sup +2}; 120 ± 20 AU), GJ 3629 B (64{sub ?23}{sup +30} M {sub Jup}; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M {sub Jup}; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M {sub Jup}; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M {sub Jup} planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M {sub Jup} range like those orbiting HR 8799 and ? Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M {sub Jup}) companions to single M dwarfs between 10-100 AU is 2.8{sub ?1.5}{sup +2.4}%. Altogether we find that giant planets, especially massive ones, are rare in the outskirts of M dwarf planetary systems. Although the first directly imaged planets were found around massive stars, there is currently no statistical evidence for a trend of giant planet frequency with stellar host mass at large separations as predicted by the disk instability model of giant planet formation.

  16. Accretion of Jupiter's Atmosphere from a

    E-print Network

    Throop, Henry

    Accretion of Jupiter's Atmosphere from a Supernova-Contaminated Molecular Cloud Henry Throop 2010, #1409 #12;Jupiter's Atmosphere · Mass Spectrometer aboard Galileo Probe · Measured atomic and molecular species to ~20 bars · Found Jupiter atmosphere to be 2-6x higher in metals vs. Sun · C, S,Ar, Kr

  17. Photometric Follow-up Observations of the Transiting Neptune-Mass Planet GJ 436b

    E-print Network

    Avi Shporer; Tsevi Mazeh; Frederic Pont; Joshua N. Winn; Matthew J. Holman; David W. Latham; Gilbert A. Esquerdo

    2008-12-24

    This paper presents multi-band photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of 5 new ground-based transit light curves obtained in May 2007. Together with one already published light curve we have at hand a total of 6 light curves, spanning 29 days. The analysis of the data yields an orbital period P = 2.64386+-0.00003 days, mid-transit time T_c [HJD] =2454235.8355+-0.0001, planet mass M_p = 23.1+-0.9 M_{\\earth} = 0.073+-0.003 M_{Jup}, planet radius R_p = 4.2+-0.2 R_{\\earth} = 0.37+-0.01 R_{Jup} and stellar radius R_s = 0.45+-0.02 R_{\\sun}. Our typical precision for the mid transit timing for each transit is about 30 seconds. We searched the data for a possible signature of a second planet in the system through transit timing variations (TTV) and variation of the impact parameter. The analysis could not rule out a small, of the order of a minute, TTV and a long-term modulation of the impact parameter, of the order of +0.2 year^{-1}.

  18. Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass Stars

    NASA Astrophysics Data System (ADS)

    Ciesla, Fred J.; Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-05-01

    Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our solar system. Here we consider how the water content of planetesimals may be higher in many planetary systems, as they could lack the short-lived radionuclides that drove water loss in carbonaceous chondrites in our solar system. Using N-body simulations, we explore how planetary accretion would be different if bodies beyond the water line contained a water-mass fraction consistent with chemical equilibrium calculations, and more similar to comets, as opposed to the more traditional water-depleted values. We apply this model to consider planet formation around stars of different masses and identify trends in the properties of habitable zone planets and planetary system architecture that could be tested by ongoing exoplanet census data collection. Comparison of such data with the model-predicted trends will serve to evaluate how well the N-body simulations and the initial conditions used in studies of planetary accretion can be used to understand this stage of planet formation.

  19. A FRAMEWORK FOR CHARACTERIZING THE ATMOSPHERES OF LOW-MASS LOW-DENSITY TRANSITING PLANETS

    SciTech Connect

    Fortney, Jonathan J.; Nettelmann, Nadine; Mordasini, Christoph; Kempton, Eliza M.-R.; Greene, Thomas P.; Zahnle, Kevin

    2013-09-20

    We perform modeling investigations to aid in understanding the atmospheres and composition of small planets of ?2-4 Earth radii, which are now known to be common in our Galaxy. GJ 1214b is a well-studied example whose atmospheric transmission spectrum has been observed by many investigators. Here we take a step back from GJ 1214b to investigate the role that planetary mass, composition, and temperature play in impacting the transmission spectra of these low-mass low-density (LMLD) planets. Under the assumption that these planets accrete modest hydrogen-dominated atmospheres and planetesimals, we use population synthesis models to show that predicted metal enrichments of the H/He envelope are high, with metal mass fraction Z{sub env} values commonly 0.6-0.9, or ?100-400+ times solar. The high mean molecular weight of such atmospheres (? ? 5-12) would naturally help to flatten the transmission spectrum of most LMLD planets. The high metal abundance would also provide significant condensible material for cloud formation. It is known that the H/He abundance in Uranus and Neptune decreases with depth, and we show that atmospheric evaporation of LMLD planets could expose atmospheric layers with gradually higher Z{sub env}. However, values of Z{sub env} close to solar composition can also arise, so diversity should be expected. Photochemically produced hazes, potentially due to methane photolysis, are another possibility for obscuring transmission spectra. Such hazes may not form above T{sub eq} of ?800-1100 K, which is testable if such warm, otherwise low mean molecular weight atmospheres are stable against atmospheric evaporation. We find that available transmission data are consistent with relatively high mean molecular weight atmospheres for GJ 1214b and 'warm Neptune' GJ 436b. We examine future prospects for characterizing GJ 1214b with Hubble and the James Webb Space Telescope.

  20. New Constraints on the Composition of Jupiter from Galileo Measurements and Interior Models

    E-print Network

    Tristan Guillot; Daniel Gautier; William B. Hubbard

    1997-07-17

    Using the helium abundance measured by Galileo in the atmosphere of Jupiter and interior models reproducing the observed external gravitational field, we derive new constraints on the composition and structure of the planet. We conclude that, except for helium which must be more abundant in the metallic interior than in the molecular envelope, Jupiter could be homogeneous (no core) or could have a central dense core up to 12 Earth masses. The mass fraction of heavy elements is less than 7.5 times the solar value in the metallic envelope and between 1 and 7.2 times solar in the molecular envelope. The total amount of elements other than hydrogen and helium in the planet is between 11 and 45 Earth masses.

  1. KEPLER PLANETS: A TALE OF EVAPORATION

    SciTech Connect

    Owen, James E.; Wu, Yanqin E-mail: wu@astro.utoronto.ca

    2013-10-01

    Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ?0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R{sub ?}. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ?0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M{sub ?} and the majority of them should have core masses of a few Earth masses.

  2. Kepler Planets: A Tale of Evaporation

    NASA Astrophysics Data System (ADS)

    Owen, James E.; Wu, Yanqin

    2013-10-01

    Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ~0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R ?. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ~0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M ? and the majority of them should have core masses of a few Earth masses.

  3. A sub-Saturn Mass Planet, MOA-2009-BLG-319Lb

    E-print Network

    Miyake, N; Dong, Subo; Street, R; Mancini, L; Gould, A; Bennett, D P; Tsapras, Y; Yee, J C; Albrow, M D; Bond, I A; Fouque, P; Browne, P; Han, C; Snodgrass, C; Finet, F; Furusawa, K; Harpsoe, K; Allen, W; Hundertmark, M; Freeman, M; Suzuki, D; Abe, F; Botzler, C S; Douchin, D; Fukui, A; Hayashi, F; Hearnshaw, J B; Hosaka, S; Itow, Y; Kamiya, K; Kilmartin, P M; Korpela, A; Lin, W; Ling, C H; Makita, S; Masuda, K; Matsubara, Y; Muraki, Y; Nagayama, T; Nishimoto, K; Ohnishi, K; Perrott, Y C; Rattenbury, N; Saito, To; Skuljan, L; Sullivan, D J; Sweatman, W L; Tristram, P J; Wada, K; Yock, P C M; Bolt, G; Bos, M; Christie, G W; DePoy, D L; Drummond, J; Gal-Yam, A; Gaudi, B S; Gorbikov, E; Higgins, D; Janczak, K -H Hwang J; Kaspi, S; Lee, C -U; Koo, J -R; lowski, S Koz; Lee, Y; Mallia, F; Maury, A; Maoz, D; McCormick, J; Monard, L A G; Moorhouse, D; Mu~noz, J A; Natusch, T; Ofek, E O; Pogge, R W; Polishook, D; Santallo, R; Shporer, A; Spector, O; Thornley, G; Allan, A; Bramich, D M; Horne, K; Kains, N; Steele, I; Bozza, V; Burgdorf, M J; Novati, S Calchi; Dominik, M; Dreizler, S; Glitrup, M; Hessman, F V; Hinse, T C; Jorgensen, U G; Liebig, C; Maier, G; Mathiasen, M; Rahvar, S; Ricci, D; Scarpetta, G; Skottfelt, J; Southworth, J; Surdej, J; Wambsganss, J; Zimmer, F; Batista, V; Beaulieu, J P; Brillant, S; Cassan, A; Cole, A; Corrales, E; Coutures, Ch; Dieters, S; Greenhill, J; Kubas, D; Menzies, J

    2015-01-01

    We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K or M-dwarf star in the inner Galactic disk or Galactic bulge. The high cadence observations of the MOA-II survey discovered this microlensing event and enabled its identification as a high magnification event approximately 24 hours prior to peak magnification. As a result, the planetary signal at the peak of this light curve was observed