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1

The Nine Planets: Jupiter  

NSDL National Science Digital Library

This page of Nine Planets contains details about the gas giant planet Jupiter. Information includes planet diameter, mass, distance from the Sun, orbit, and mythology. Also covered are planet composition, surface features, atmosphere and magnetic field data, results from exploration spacecraft, and temperature on the planet. Jupiters' moons are also covered in detail, including Io, Europa, Ganymede, Callisto, and others. The site provides links to more images and facts, and discusses unanswered questions about Jupiter and its moons.

Arnett, Bill

2

Accretion of Jupiter-mass Planets in the Limit of Vanishing Viscosity  

NASA Astrophysics Data System (ADS)

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 ~104 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.

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

2014-02-01

3

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

NASA Technical Reports Server (NTRS)

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.

1975-01-01

4

A Long-Period Jupiter-Mass Planet Orbiting the Nearby M Dwarf GJ849  

E-print Network

We report precise Doppler measurements of GJ849 (M3.5V) that reveal the presence of a planet with a minimum mass of 0.82 Mjup in a 5.16 year orbit. At a = 2.35 AU, GJ849b is the first Doppler-detected planet discovered around an M dwarf to orbit beyond 0.21 AU, and is only the second Jupiter mass planet discovered around a star less massive than 0.5 Msun. This detection brings to 4 the number of M stars known to harbor planets. Based on the results of our survey of 1300 FGKM main--sequence stars we find that giant planets within 2.5 AU are ~3 times more common around GK stars than around M stars. Due to the GJ849's proximity of 8.8 pc, the planet's angular separation is 0."27, making this system a prime target for high--resolution imaging using adaptive optics and future space--borne missions such as the Space Interferometry Mission. We also find evidence of a linear trend in the velocity time series, which may be indicative of an additional planetary companion.

R. Paul Butler; John A. Johnson; Geoffrey W. Marcy; Jason T. Wright; Steven S. Vogt; Debra A. Fischer

2006-10-06

5

Exploring the Planets: Jupiter  

NSDL National Science Digital Library

This site contains most of the up-to-date information known about the planet Jupiter, including mean distance from the Sun, length of year, rotation period, mean orbital velocity, inclination of axis, spacecraft encounters, diameter, and number of observed satellites. The Galilean satellites Callisto, Ganymede, Europa, and Io are shown here in their correct positions relative to the planet and the odd moon Amalthea is discussed. There is tabular data on several of the other major moons. There are many thumbnail photographs that can be enlarged, including a grand view of the red spot. The radiation and radio noise of Jupiter is discussed, along with its atmosphere as compared to Saturn. The Galileo mission is discussed and links are provided for more information.

6

The SOPHIE search for northern extrasolar planets. III. A Jupiter-mass companion around HD 109246  

NASA Astrophysics Data System (ADS)

We report the detection of a Jupiter-mass planet discovered with the SOPHIE spectrograph mounted on the 1.93-m telescope at the Haute-Provence Observatory. The new planet orbits HD 109246, a G0V star slightly more metallic than the Sun. HD 109246b has a minimum mass of 0.77 MJup, an orbital period of 68 days, and an eccentricity of 0.12. It is placed in a sparsely populated region of the period distribution of extrasolar planets. We also present a correction method for the so-called seeing effect that affects the SOPHIE radial velocities. We complement this discovery announcement with a description of some calibrations that are implemented in the SOPHIE automatic reduction pipeline. These calibrations allow the derivation of the photon-noise radial velocity uncertainty and some useful stellar properties (v sin i, [Fe/H], log R’HK) directly from the SOPHIE data. Based on observations made with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS/OAMP), France (program 07A.PNP.CONS).RV tables (Tables C.1 and C.2) are only available in electronic form 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/523/A88

Boisse, I.; Eggenberger, A.; Santos, N. C.; Lovis, C.; Bouchy, F.; Hébrard, G.; Arnold, L.; Bonfils, X.; Delfosse, X.; Desort, M.; Díaz, R. F.; Ehrenreich, D.; Forveille, T.; Gallenne, A.; Lagrange, A. M.; Moutou, C.; Udry, S.; Pepe, F.; Perrier, C.; Perruchot, S.; Pont, F.; Queloz, D.; Santerne, A.; Ségransan, D.; Vidal-Madjar, A.

2010-11-01

7

Jupiter: Lord of the Planets.  

ERIC Educational Resources Information Center

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)

Kaufmann, William

1984-01-01

8

ACCRETION OF ROCKY PLANETS BY HOT JUPITERS  

SciTech Connect

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.

Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M. [Michigan Center for Theoretical Physics, Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-11-01

9

Extrasolar planets: What are hot Jupiters made of?  

Microsoft Academic Search

Among the 100 or so extrasolar planets discovered to date, the most bizarre are the dozen or so Jupiter-mass planets that orbit their parent stars with periods between three and seven days. These so-called ``hot Jupiters'' offer the most immediate chances for direct detection and characterization. At present only one of these planets has been found to transit the face

Andrew Collier Cameron

2002-01-01

10

The Planet Jupiter  

NSDL National Science Digital Library

This resource covers the general features of Jupiter: its atmosphere and interior, including liquid metallic hydrogen, and its internal energy source; the Great Red Spot; its magnetic field, magnetosphere and auroras; and its ring.

2007-06-06

11

PLANETARY ATMOSPHERES Jupiter and the Outer Planets  

E-print Network

PLANETARY ATMOSPHERES Contents Jupiter and the Outer Planets Mars Venus Jupiter and the Outer range of atmospheres. The giant planets F Jupiter, Saturn, Uranus, and Neptune F are fluid objects whose equilibrium with solid nitrogen ice on their surfaces. And the Galilean satellites of Jupiter F Io, Europa

12

Two Jupiter-Mass Planets Orbiting HD 154672 and HD 205739  

E-print Network

We report the detection of the first two planets from the N2K Doppler planet search program at the Magellan telescopes. The first planet has a mass of M sin i = 4.96 M_Jup and is orbiting the G3 IV star HD154672 with an orbital period of 163.9 days. The second planet is orbiting the F7 V star HD205739 with an orbital period of 279.8 days and has a mass of M sin i = 1.37 M_Jup. Both planets are in eccentric orbits, with eccentricities e = 0.61 and e = 0.27, respectively. Both stars are metal rich and appear to be chromospherically inactive, based on inspection of their Ca II H and K lines. Finally, the best Keplerian model fit to HD205739b shows a trend of 0.0649 m/s/day, suggesting the presence of an additional outer body in that system.

Mercedes Lopez-Morales; R. Paul Butler; Debra A. Fischer; Dante Minniti; Stephen A. Shectman; Genya Takeda; Fred C. Adams; Jason T. Wright; Pamela Arriagada

2008-09-05

13

A binary merger origin for inflated hot Jupiter planets  

Microsoft Academic Search

We hypothesize that hot Jupiters with inflated sizes represent a separate planet formation channel, the merging of two low-mass stars. We show that the abundance and properties of W UMa stars and low mass detached binaries are consistent with their being possible progenitors. The degree of inflation of the transiting hot Jupiters correlates with their expected spiral-in life time by

E. L. Martin; H. C. Spruit; R. Tata

2011-01-01

14

Hot Jupiters from secular planet-planet interactions.  

PubMed

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

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

2011-05-12

15

Effects of Roche Lobe Overflow from Eccentric Hot Jupiters Created by Planet-Planet Scattering  

NASA Astrophysics Data System (ADS)

As the number of extra solar planets and planet candidates increases, so does the number of systems that look strikingly different from our own. In this poster, we explore the creation of close-in eccentric Jupiter-mass planets. We show that planet-planet scattering can create a significant population of hot Jupiters that pass close enough to their parent stars to undergo Roche Lobe overflow (RLOF) at periastron. We investigate the distribution of these eccentric, Roche-Lobe-overfilling planets and study their subsequent orbital evolution. We find that depending on the mass accretion rate and tidal quality factor there are regimes where changes in the orbital properties due to RLOF at periastron is comparable or even higher than to those due to static tides. Our results suggest that RLOF from planets in such eccentric orbits may be a contributing factor in the creation of some long-lived eccentric Hot Jupiters.

Sepinsky, Jeremy F.; Salmon, R. L.; Chatterjee, S.

2014-01-01

16

KOI-183b: a half-Jupiter mass planet transiting a very old solar-like star  

E-print Network

We report the spectroscopic confirmation of the Kepler object of interest KOI-183b (also known as KOI-183.01), a half-Jupiter mass planet transiting an old solar-like star every 2.7 days. Our analysis is the first to combine the full Kepler photometry (quarters 1-17) with high-precision radial velocity measurements taken with the FIES spectrograph at the Nordic Optical Telescope. We simultaneously modelled the photometric and spectroscopic data-sets using Bayesian approach coupled with Markov chain Monte Carlo sampling. We found that the Kepler pre-search data conditioned (PDC) light curve of KOI-183 exhibits quarter-to-quarter systematic variations of the transit depth, with a peak-to-peak amplitude of about 4.3 % and seasonal trends reoccurring every four quarters. We attributed these systematics to an incorrect assessment of the quarterly variation of the crowding metric. The host star KOI-183 is a G4 dwarf with $M_\\star=0.85\\pm0.04$ M$_\\rm{Sun}$, $R_\\star=0.95\\pm0.04$ R$_\\rm{Sun}$, $T_\\mathrm{eff}=5560\\pm...

Gandolfi, D; Deeg, H J; Lanza, A F; Fridlund, M; Moroni, P G Prada; Alonso, R; Augusteijn, T; Cabrera, J; Evans, T; Geier, S; Hatzes, A P; Holczer, T; Hoyer, S; Kangas, T; Mazeh, T; Pagano, I; Tal-Or, L; Tingley, B

2014-01-01

17

Kepler constraints on planets near hot Jupiters.  

PubMed

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

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

18

Kepler constraints on planets near hot Jupiters  

PubMed Central

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

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

19

Kepler constraints on planets near hot Jupiters  

SciTech Connect

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.

Steffen, Jason H.; /Fermilab; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Fabrycky, Daniel C.; /UC, Santa Cruz, Astron. Astrophys.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames; Welsh, William F.; /San Diego State U., Astron. Dept.; Borucki, William J.; /NASA, Ames; Boss, Alan P.; /Carnegie Inst., Wash., D.C., DTM; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

2012-05-01

20

The Observational Case for Jupiter Being a Typical Massive Planet  

E-print Network

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

Lineweaver, Charles H.

21

Jupiter analogues and planets of active stars  

NASA Astrophysics Data System (ADS)

Combined results are now available from a 15 year long search for Jupiter analogues around solar-type stars using the ESO CAT + CES, ESO 3.6 m + CES, and ESO 3.6 m + HARPS instruments. They comprise planet (co-)discoveries (? Hor and HR 506) and confirmations (three planets in HR 3259) as well as non-confirmations of planets (HR 4523 and ? Eri) announced elsewhere. A long-term trend in ? Ind found by our survey is probably attributable to a Jovian planet with a period >30 yr, but we cannot fully exclude stellar activity effects as the cause. A 3.8 year periodic variation in HR 8323 can be attributed to stellar activity.

Kürster, M.; Zechmeister, M.; Endl, M.; Lo Curto, G.; Hartman, H.; Nilsson, H.; Henning, T.; Hatzes, A. P.; Cochran, W. D.

2013-04-01

22

Disk Accretion onto High-Mass Planets  

Microsoft Academic Search

We analyze the nonlinear, two-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of one Jupiter mass (1 MJ) and greater that orbits a 1 Msolar star by using the ZEUS hydrodynamics code with high resolution near the planet's Roche lobe. The planet is assumed to be in a circular orbit around the central star

S. H. Lubow; M. Seibert; P. Artymowicz

1999-01-01

23

Can Terrestrial Planets Form in Hot-Jupiter Systems?  

Microsoft Academic Search

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.

M. J. Fogg; R. P. Nelson

2008-01-01

24

Can Terrestrial Planets Form in Hot-Jupiter Systems?  

E-print Network

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.

Martyn J. Fogg; Richard P. Nelson

2007-10-19

25

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

SciTech Connect

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.

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. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Andersen, J. [Niels Bohr Institute, Copenhagen University (Denmark); Kovacs, G. [Konkoly Observatory, Budapest (Hungary); Shporer, A. [Las Cumbres Observatory Global Telescope Network, Goleta, CA (United States); Fischer, D. A. [Department of Astronomy, Yale University, New Haven, CT (United States); Johnson, J. A. [Department of Astrophysics, California Institute of Technology, Pasadena, CA (United States); Marcy, G. W.; Howard, A. W. [Department of Astronomy, University of California, Berkeley, CA (United States)

2011-06-01

26

Multiple-Planet Scattering and the Origin of Hot Jupiters  

Microsoft Academic Search

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. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization. We considered planetary systems having 3 and 4 planets initially. We found

C. Beauge; D. Nesvorny

2011-01-01

27

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

E-print Network

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

Hamilton, Douglas P.

28

Scientists Revise Thinking on Comets, Planet Jupiter  

ERIC Educational Resources Information Center

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)

Chemical and Engineering News, 1974

1974-01-01

29

MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS  

SciTech Connect

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.

Beauge, C. [Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, X5000BGR Cordoba (Argentina); Nesvorny, D. [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

2012-06-01

30

Multiple-planet Scattering and the Origin of Hot Jupiters  

NASA Astrophysics Data System (ADS)

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.

Beaugé, C.; Nesvorný, D.

2012-06-01

31

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)

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.

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

32

Investigation of hydrogen and helium pumping by sputter ion pumps for Jupiter and outer planets mass spectrometer  

NASA Technical Reports Server (NTRS)

The phenomena of ion pumping is reviewed with emphasis on the pumping mechanism for hydrogen and helium. The experimental tests measure the performance of a small, flight proven ion pump which has a nominal four liter/second pumping speed for air. The speed of this pump for hydrogen and helium, and for hydrogen/helium mixes, is presented with particular detail regarding the time dependence. Pump test results are related to anticipated performance of the mass spectrometer by the pumping speeds for the gases to the partial pressure in the ion source. From this analysis, the pump specifications are quantified in terms of mission goals and in terms of observed pumping speeds for the various gases, load levels, and time periods.

Scott, B. W.

1977-01-01

33

Can Terrestrial Planets Form in Hot-Jupiter Systems?  

Microsoft Academic Search

Models of terrestrial planet formation in the presence of a migrating giant\\u000aplanet have challenged the notion that hot-Jupiter systems lack terrestrial\\u000aplanets. We briefly review this issue and suggest that hot-Jupiter systems\\u000ashould be prime targets for future observational missions designed to detect\\u000aEarth-sized and potentially habitable worlds.

Martyn J. Fogg; Richard P. Nelson

2007-01-01

34

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

E-print Network

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 ...

Weiss, Lauren M.

35

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

SciTech Connect

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.

Di Stefano, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-06-20

36

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

E-print Network

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 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 size of measurement errors and stellar jitter. We show that all planets with orbital periods 20 m/s, and eccentricities orbital periods. For the remaining stars, we calculate upper limits on the velocity amplitude of a companion, typically 10 m/s, and use the non-detections to derive completeness corrections at low amplitudes and long orbital periods. We give the fraction of stars with a planet as a function of planet mass and orbital period, and extrapolate to long period orbits and low planet masses. A power law fit for planet masses >0.3 Jupiter masses and periods planet with mass in the range 0.3-10 Jupiter masses 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 beyond 300 days. Extrapolation gives 17-20% of stars having gas giant planets within 20 AU. Finally, taking into account differences in detectability, we find that M dwarfs are 3 to 10 times less likely to harbor a Jupiter mass planet than solar type stars.

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

2008-03-24

37

The Observational Case for Jupiter Being a Typical Massive Planet  

Microsoft Academic Search

We identify a subsample of the recently detected extrasolar planets that is minimally affected by the selection effects of the Doppler detection method. With a simple analysis we quantify trends in the surface density of this subsample in the period-Msin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus

Charles H. Lineweaver; Daniel Grether

2002-01-01

38

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

E-print Network

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.

A. Bhardwaj; M. Michael

2002-09-04

39

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

Microsoft Academic Search

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

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

2008-01-01

40

Disk Accretion Onto High-Mass Planets  

E-print Network

We analyze the nonlinear, two-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of one Jupiter mass (1 M_J) and greater that orbits a 1 solar mass star by using the ZEUS hydrodynamics code with high resolution near the planet's Roche lobe. The planet is assumed to be in a circular orbit about the central star and is not allowed to migrate. A gap is formed about the orbit of the planet, but there is a nonaxisymmetric flow through the gap and onto the planet. The gap partitions the disk into an inner (outer) disk that extends inside (outside) the planet's orbit. For a 1 M_J planet and typical disk parameters, the accretion through the gap onto the planet is highly efficient. For typical disk parameters, the mass doubling time scale is less than 10^5 years, considerably shorter than the disk lifetime. Following shocks near the L1 and L2 Lagrange points, disk material enters the Roche lobe in the form of two gas streams. Shocks occur within the Roche lobe as the gas stream...

Lubow, S H; Artymowicz, P

1999-01-01

41

Exploring the Diversity of Jupiter-Class Planets (Discussion Meeting Contribution)  

E-print Network

Royal Society Discussion Meeting (2013) `Characterizing exoplanets'. 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 (0.3MJ), 53% are more massive than Jupiter, and 67% are within 1 AU of their host stars. And yet the term `hot Jupiter' fails to account for the incredible diversity of this class of 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 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 classification at this early stage of exoplanetary spectroscopy. We discuss the range of p...

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

2014-01-01

42

Jupiter  

NSDL National Science Digital Library

This site discusses the planet Jupiter. Some of the topics discussed include: its interior, surface, and atmosphere, its magnetosphere, its moons and rings, missions, myths, and latest news. There is also numerous pictures and additional websites for more information.

2005-06-07

43

WASP-94 A and B planets: hot-Jupiter cousins in a twin-star system  

NASA Astrophysics Data System (ADS)

We report the discovery of two hot-Jupiter planets, each orbiting one of the stars of a wide binary system. WASP-94A (2MASS 20550794-3408079) is an F8 type star hosting a transiting planet with a radius of 1.72 ± 0.06 RJup, a mass of 0.452 ± 0.034 MJup, and an orbital period of 3.95 days. The Rossiter-McLaughlin effect is clearly detected, and the measured projected spin-orbit angle indicates that the planet occupies a retrograde orbit. WASP-94B (2MASS 20550915-3408078) is an F9 stellar companion at an angular separation of 15'' (projected separation 2700 au), hosting a gas giant with a minimum mass of 0.618 ± 0.028 MJup with a period of 2.008 days, detected by Doppler measurements. The orbital planes of the two planets are inclined relative to each other, indicating that at least one of them is inclined relative to the plane of the stellar binary. These hot Jupiters in a binary system bring new insights into the formation of close-in giant planets and the role of stellar multiplicity. The radial-velocity and photometric data used for this work are only 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/572/A49

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

2014-12-01

44

WASP-94 A and B planets: hot-Jupiter cousins in a twin-star system  

E-print Network

We report the discovery of two hot-Jupiter planets, each orbiting one of the stars of a wide binary system. WASP-94A (2MASS 20550794-3408079) is an F8 type star hosting a transiting planet with a radius of 1.72 +/- 0.06 R_Jup, a mass of 0.445 +/- 0.026 M_Jup, and an orbital period of 3.95 days. The Rossiter-McLaughlin effect is clearly detected, and the measured projected spin-orbit angle indicates that the planet occupies a retrograde orbit. WASP-94B (2MASS 20550915-3408078) is an F9 stellar companion at an angular separation of 15" (projected separation 2700 au), hosting a gas giant with a minimum mass of 0.617 +/- 0.028 M_Jup with a period of 2.008 days, detected by Doppler measurements. The orbital planes of the two planets are inclined relative to each other, indicating that at least one of them is inclined relative to the plane of the stellar binary. These hot Jupiters in a binary system bring new insights into the formation of close-in giant planets and the role of stellar multiplicity.

Neveu-VanMalle, M; Anderson, D R; Charbonnel, C; Cameron, A Collier; Delrez, L; Gillon, M; Hellier, C; Jehin, E; Lendl, M; Maxted, P F L; Pepe, F; Pollacco, D; Segransan, D; Smalley, B; Smith, A M S; Southworth, J; Triaud, A H M J; Udry, S; West, R G

2014-01-01

45

ELODIE metallicity-biased search for transiting Hot Jupiters V. An intermediate-period Jovian planet orbiting HD45652  

E-print Network

We present the detection of a 0.47 Jupiter mass planet in a 44-day period eccentric trajectory (e=0.39) orbiting the metal-rich star HD45652. This planet, the seventh giant planet discovered in the context of the ELODIE metallicity-biased planet search program, is also confirmed using higher precision radial-velocities obtained with the CORALIE and SOPHIE spectrographs. The orbital period of HD45652b places it in the middle of the "gap" in the period distribution of extra-solar planets.

N. C. Santos; S. Udry; F. Bouchy; R. Da Silva; B. Loeillet; M. Mayor; C. Moutou; F. Pont; D. Queloz; S. Zucker; D. Naef; F. Pepe; D. Segransan; I. Boisse; X. Bonfils; X. Delfosse; M. Desort; T. Forveille; G. Hebrard; A. -M. Lagrange; C. Lovis; C. Perrier; A. Vidal-Madjar

2008-05-07

46

Jupiter  

NSDL National Science Digital Library

This NASA (National Aeronautics and Space Administration) planet profile provides data and images of the planet Jupiter. These data include planet size, orbit facts, distance from the Sun, rotation and revolution times, temperature, atmospheric composition, density and albedo. Images with descriptions include the Jovian system, the great red spot, clouds in Jupiters atmosphere, and the ring system. Moon images show Io and its volcanics, Callisto with its craters and the Valhalla Basin, Europa, and Ganymede with its tectonic features. All of the images on this page were taken by the Voyager Spacecraft.

47

Three-Dimensional Simulations of High and Low-Mass Planets Embedded in Protoplanetary Disks  

Microsoft Academic Search

We analyze the non-linear, three-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of mass ranging from one Earth mass to one Jupiter mass by using the ZEUS hydrodynamics code. We determine the gas flow pattern, and the accretion and migration rates of the planet. The planet is assumed to be in a fixed circular

S. H. Lubow; M. R. Bate; G. I. Ogilvie; K. A. Miller

2003-01-01

48

Three-dimensional calculations of high- and low-mass planets embedded in protoplanetary discs  

Microsoft Academic Search

We analyse the non-linear, three-dimensional response of a gaseous, viscous protoplanetary disc to the presence of a planet of mass ranging from 1 Earth mass (1 M?) to 1 Jupiter mass (1 MJ) by using the ZEUS hydrodynamics code. We determine the gas flow pattern, and the accretion and migration rates of the planet. The planet is assumed to be

M. R. Bate; S. H. Lubow; G. I. Ogilvie; K. A. Miller

2003-01-01

49

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

E-print Network

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. It is sensitive down to Jupiter mass planets. Out of the twelve monitored very low-mass stars and brown dwarfs

Joergens, Viki

50

The Anglo-Australian Planet Search. XXIII. Two New Jupiter Analogs  

NASA Astrophysics Data System (ADS)

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 Jup; HD 154857c has P = 9.5 yr and msin i = 2.6 M 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 108 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.

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

2014-03-01

51

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

PubMed

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

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

52

Final state of thermal evolution of Jupiter-type planet  

NASA Astrophysics Data System (ADS)

Inside the planet consisting mostly of hydrogen (the Jupiter-type planet), in the last stage of the thermal evolution there should be induced the high-temperature superconducting state. In particular, for the effective temperature of the planet (TS equal to about 5 K), the superconducting phase of hydrogen will appear near the value of the pressures p1?500 GPa and p2?2000 GPa. Together with the further lowering of the temperature, the superconducting state will be induced in the hydrogen layers with the pressure successively distant from p1 and p2. The last superconducting layer will be created for p?400 GPa, at the moment, when TS drops to about 1.3 K. It has been also shown that the rotating planet, in which the superconducting state was induced, is the source of the very weak magnetic field of the induction equal to about 10-11 Gs. The results have been obtained on the basis of the analysis of the thermodynamic properties of the superconducting state in hydrogen subjected to the influence of the extremely high pressure at 3500 GPa (close to the core of the hypothetical planet) and on the basis of the literature describing the superconducting phase in hydrogen at the lower pressures.

Szcze&?acute; niak, R.; Duda, A. M.; Drzazga, E. A.

2014-06-01

53

Jupiter and the Extrasolar Giant Planets: Composition and origin of atmospheres  

Microsoft Academic Search

In this paper, we will discuss the related issues of the composition and origin of Jupiter's atmosphere, and how this can help in understanding the atmospheres of the extrasolar giant planets (EGP). In the case of Jupiter, a wealth of data on the planet's atmosphere is available, largely as a result of the successful spacecraft observations by the Galileo Orbiter

S. Atreya; A. Wong; P. Mahaffy; H. Niemann; M. Wong; T. Owen

2002-01-01

54

Exploring the Relationship Between Planet Mass and Atmospheric Metallicity  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

55

XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period  

E-print Network

The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized, Rp=1.15+/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital period of P=4.187732+/-0.00002 days. The planet mass (Mp=1.15+/-0.08 Mjup) and surface gravity (gp=22+/-5 m/s^2) are significantly larger than expected by empirical Mp-P and Mp-P-[Fe/H] relationships. However, the deviation from the Mp-P relationship for XO-5b is not large enough to suggest a distinct type of planet as is suggested 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).

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

2008-05-15

56

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

E-print Network

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.

Liping Jin

2008-05-06

57

A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832  

E-print Network

Precision Doppler velocity measurements from the Anglo-Australian Tele- scope reveal a planet with a 9.4+/-0.4 year period orbiting the M1.5 dwarf GJ 832. Within measurement uncertainty the orbit is circular, and the minimum mass (m sin i) of the planet is 0.64+/-0.06 MJUP. GJ 832 appears to be depleted in met- als by at least 50% relative to the Sun, as are a significant fraction of the M dwarfs known to host exoplanets. GJ 832 adds another Jupiter-mass planet to the known census of M dwarf exoplanets, which currently includes a significant number of Neptune-mass planets. GJ 832 is an excellent candidate for astromet- ric orbit determination with alpha sin i = 0.95 mas. GJ 832b has the second largest angular distance from its star among radial velocity detected exoplanets (0.69 arc sec) making it a potentially interesting target for future direct detection.

Jeremy Bailey; R. Paul Butler; C. G. Tinney; Hugh R. A. Jones; Simon O'Toole; Brad D. Carter; Geoffrey W. Marcy

2008-09-01

58

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

NASA Technical Reports Server (NTRS)

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.

1975-01-01

59

XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period  

Microsoft Academic Search

The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized,\\u000aRp=1.15+\\/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital\\u000aperiod of P=4.187732+\\/-0.00002 days. The planet mass (Mp=1.15+\\/-0.08 Mjup) and\\u000asurface gravity (gp=22+\\/-5 m\\/s^2) are significantly larger than expected by\\u000aempirical Mp-P and Mp-P-[Fe\\/H] relationships. However, the deviation from the\\u000aMp-P relationship for XO-5b is not large enough to suggest a

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

2008-01-01

60

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

61

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

PubMed

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

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

2011-07-14

62

A Jupiter-mass companion to a solar-type star  

Microsoft Academic Search

The presence of a Jupiter-mass companion to the star 51 Pegasi is inferred from observations of periodic variations in the star's radial velocity. The companion lies only about eight million kilometres from the star, which would be well inside the orbit of Mercury in our Solar System. This object might be a gas-giant planet that has migrated to this location

Michel Mayor; Didier Queloz

1995-01-01

63

Formation of terrestrial planets in a dissipating gas disk with Jupiter and Saturn  

Microsoft Academic Search

We have performed N-body simulations on final accretion stage of terrestrial planets, including the eccentricity and inclination damping effect due to tidal interaction with a gas disk. We investigated the dependence on a depletion time scale of the disk, and the effect of secular perturbations by Jupiter and Saturn. In the final stage, terrestrial planets are formed through coagulation of

Junko Kominami; Shigeru Ida

2004-01-01

64

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

ERIC Educational Resources Information Center

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…

1973

65

Three-dimensional Calculations of High and Low-mass Planets Embedded in Protoplanetary Discs  

Microsoft Academic Search

We analyse the non-linear, three-dimensional response of a gaseous, viscous\\u000aprotoplanetary disc to the presence of a planet of mass ranging from one Earth\\u000amass (1 M$_e$) to one Jupiter mass (1 M$_J$) by using the ZEUS hydrodynamics\\u000acode. We determine the gas flow pattern, and the accretion and migration rates\\u000aof the planet. The planet is assumed to be

M. R. Bate; S. H. Lubow; G. I. Ogilvie; K. A. Miller

2003-01-01

66

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  

E-print Network

We revisit the calculation of the Ohmic dissipation in a hot Jupiter presented in Laine et al. (2008) 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 modelled 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 co-rotation 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/anti-parallel 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 in Laine...

Chang, Yu-Ling; Gu, Pin-Gao

2012-01-01

67

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

SciTech Connect

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.

Szabo, Gy. M.; Kiss, L. L. [Konkoly Observatory of the Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary)

2011-02-01

68

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

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

69

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

E-print Network

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.

J. Marvin Herndon

2006-12-20

70

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

NASA Astrophysics Data System (ADS)

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.

Houston Jones, J.; Dyches, P.

2012-12-01

71

Mass-loss Evolution of Close-in Exoplanets: Evaporation of Hot Jupiters and the Effect on Population  

NASA Astrophysics Data System (ADS)

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 (sime 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.

Kurokawa, H.; Nakamoto, T.

2014-03-01

72

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

SciTech Connect

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.

Mandushev, Georgi; Dunham, Edward W. [Lowell Observatory, 1400 W Mars Hill Rd, Flagstaff, AZ 86001 (United States); Quinn, Samuel N.; Latham, David W.; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Buchhave, Lars A. [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Rabus, Markus [Departamento de Astonomia y Astrofisica, Ponticia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Oetiker, Brian [Department of Physics, Sam Houston State University, Huntsville, TX 77340 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope, 6740 Cortona Dr, Suite 102, Goleta, CA 93117 (United States); Belmonte, Juan A. [Instituto de Astrofisica de Canarias, C/ via Lactea s/n, 38200 La Laguna, Tenerife (Spain); O'Donovan, Francis T., E-mail: gmand@lowell.edu [Ab Initio Software, 201 Spring St, Lexington, MA 02421 (United States)

2011-11-10

73

The Deuterium-burning Mass Limit for Brown Dwarfs and Giant Planets  

Microsoft Academic Search

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 (MJ ) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 MJ is generally a reasonable rule

David S. Spiegel; Adam Burrows; John A. Milsom

2011-01-01

74

Transit thermal control design for Galileo entry probe for planet Jupiter  

NASA Technical Reports Server (NTRS)

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.

Haverly, G. C.; Pitts, W.

1982-01-01

75

Characterizing Low-Mass Planets in Kepler's Multi-Planet Systems with Transit Timing  

NASA Astrophysics Data System (ADS)

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. Smaller, rocky planets have also been observed in such systems. 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 will aid in revealing fundamental properties of a common class of exoplanets. There is a small sample of exoplanets with known masses and radii, mostly hot jupiters whose radii are known from transit depths, and whose masses are determined from radial velocity spectroscopy (RV). 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 modelling with Kepler data probes planetary masses over orbital periods ranging from ~5-100 days, complementing the sample of RV detections. Furthermore, in select cases, dynamical fits to observed TTVs can tightly constrain the orbital eccentricity vectors, 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. To these we add precise mass measurements of the outer planets of Kepler-33, a compact system with five known transiting planets, three of which show detectable transit timing variations. These results will be placed in the context of other mass-radius measurements for planets of similar size and orbital periods to provide a summary of our knowledge to date.

Jontof-Hutter, Daniel; Lissauer, Jack; Rowe, Jason; Fabrycky, Daniel

2014-11-01

76

Little Stars Don't Like Big Planets: An Astrometric Search for Super-Jupiters Around Red Dwarfs  

NASA Astrophysics Data System (ADS)

The astrometric detection and characterization of extrasolar planets presents considerable technical challenges, but also promises to greatly enhance our understanding of these systems. Nearly all currently confirmed exoplanets have been discovered using transit or radial velocity techniques. The former is geometrically biased towards planets with small orbits, while the latter is biased towards massive planets with short periods that exert large gravitational accelerations on their host stars. Astrometric techniques are limited by the minimum detectable perturbation of a star's position due to a planet, but allow for the determination of orbit inclination and an accurate planetary mass. Here we present astrometric solutions for five nearby stars with known planets: four M dwarfs (GJ 317, GJ 581, GJ 849, and GJ 1214) and one K dwarf (BD -10 3166). Observations have baselines of three to thirteen years, and were made using the 0.9 m telescope at CTIO as part of the RECONS long-term astrometry program. We provide improved parallaxes for the stars and find that there are no planets of several Jupiter masses or brown dwarfs orbiting these stars with periods up to twice the length of the astrometric coverage. In the broader context, these results are consistent with the paucity of super-Jupiter and brown dwarf companions we find among the roughly 200 red dwarfs searched in our astrometric program. This effort has been supported by the National Science Foundation via grant AST 09-08402 and the long-term cooperative efforts of the National Optical Astronomy Observatories and the members of the SMARTS Consortium.

Lurie, John C.; Henry, T. J.; Jao, W.; Koerner, D. W.; Riedel, A. R.; Subasavage, J.; RECONS

2013-01-01

77

What If There Were a Planet Between Mars and Jupiter?  

NSDL National Science Digital Library

This activity, a supplement to the Hall of Meteorites Educator's Guide, investigates the transition point between the rocky planets of the inner solar system and the gas planets of the outer solar system. After reviewing the characteristics of the nine planets of the inner and outer solar system, along with the asteroid belt that lies between them, students are asked to investigate this question: If these asteroids had come together at the same time and in the same way to form a 10th planet, what would it be like?

78

The Photoeccentric Effect and Proto-hot Jupiters. I. Measuring Photometric Eccentricities of Individual Transiting Planets  

NASA Astrophysics Data System (ADS)

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+0.16 - 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.

Dawson, Rebekah I.; Johnson, John Asher

2012-09-01

79

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

SciTech Connect

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.

Dawson, Rebekah I. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-10, Cambridge, MA 02138 (United States); Johnson, John Asher, E-mail: rdawson@cfa.harvard.edu [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States)

2012-09-10

80

Core-Accretion Model Predicts Few Jovian-Mass Planets Orbiting Red Dwarfs  

E-print Network

The favored theoretical explanation for giant planet formation -- in both our solar system and others -- is the core accretion model (although it still has some serious difficulties). In this scenario, planetesimals accumulate to build up planetary cores, which then accrete nebular gas. With current opacity estimates for protoplanetary envelopes, this model predicts the formation of Jupiter-mass planets in 2--3 Myr at 5 AU around solar-mass stars, provided that the surface density of solids is enhanced over that of the minimum-mass solar nebula (by a factor of a few). Working within the core-accretion paradigm, this paper presents theoretical calculations which show that the formation of Jupiter-mass planets orbiting M dwarf stars is seriously inhibited at all radial locations (in sharp contrast to solar-type stars). Planet detection programs sensitive to companions of M dwarfs will test this prediction in the near future.

Gregory Laughlin; Peter Bodenheimer; Fred C. Adams

2004-07-15

81

The sub-Jupiter mass transiting exoplanet WASP-11b  

E-print Network

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.

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

82

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

SciTech Connect

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.

Wang, Ji; Fischer, Debra A.; Boyajian, Tabetha S.; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Barclay, Thomas [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Schwamb, Megan E. [Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lintott, Chris; Simpson, Robert [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Jek, Kian J.; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Smith, Arfon M.; Parrish, Michael; Lynn, Stuart [Adler Planetarium, 1300 South Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: ji.wang@yale.edu [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland); and others

2013-10-10

83

Terrestrial planet and asteroid formation in the presence of giant planets. I. Relative velocities of planetesimals subject to Jupiter and Saturn perturbations.  

PubMed

We investigate the orbital evolution of 10(13)- to 10(25) -g planetesimals near 1 AU and in the asteroid belt (near 2.6 AU) prior to the stage of evolution when the mutual perturbations between the planetesimals become important. We include nebular gas drag and the effects of Jupiter and Saturn at their present masses and in their present orbits. Gas drag introduces a size-dependent phasing of the secular perturbations, which leads to a pronounced dip in encounter velocities (Venc) between bodies of similar mass. Plantesimals of identical mass have Venc approximately 1 and approximately 10 m s-1 (near 1 and 2.6 AU, respectively) while bodies differing by approximately 10 in mass have Venc approximately 10 and approximately 100 m s-1 (near 1 and 2.6 AU, respectively). Under these conditions, growth, rather than erosion, will occur only by collisions of bodies of nearly the same mass. There will be essentially no gravitational focusing between bodies less than 10(22) to 10(25) g, allowing growth of planetary embryos in the terrestrial planet region to proceed in a slower nonrunaway fashion. The environment in the asteroid belt will be even more forbidding and it is uncertain whether even the severely depleted present asteroid belt could form under these conditions. The perturbations of Jupiter and Saturn are quite sensitive to their semi-major axes and decrease when the planets' heliocentric distances are increased to allow for protoplanet migration. It is possible, though not clearly demonstrated, that this could produce a depleted asteroid belt but permit formation of a system of terrestrial planet embryos on a approximately 10(6)-year timescale, initially by nonrunaway growth and transitioning to runaway growth after approximately 10(5) years. The calculations reported here are valid under the condition that the relative velocities of the bodies are determined only by Jupiter and Saturn perturbations and by gas drag, with no mutual perturbations between planetesimals. If, while subject to these conditions, the bodies become large enough for their mutual perturbations to influence their velocity and size evolution significantly, the problem becomes much more complex. This problem is under investigation. PMID:11543321

Kortenkamp, S J; Wetherill, G W

2000-01-01

84

Terrestrial planet and asteroid formation in the presence of giant planets. I. Relative velocities of planetesimals subject to Jupiter and Saturn perturbations  

NASA Technical Reports Server (NTRS)

We investigate the orbital evolution of 10(13)- to 10(25) -g planetesimals near 1 AU and in the asteroid belt (near 2.6 AU) prior to the stage of evolution when the mutual perturbations between the planetesimals become important. We include nebular gas drag and the effects of Jupiter and Saturn at their present masses and in their present orbits. Gas drag introduces a size-dependent phasing of the secular perturbations, which leads to a pronounced dip in encounter velocities (Venc) between bodies of similar mass. Plantesimals of identical mass have Venc approximately 1 and approximately 10 m s-1 (near 1 and 2.6 AU, respectively) while bodies differing by approximately 10 in mass have Venc approximately 10 and approximately 100 m s-1 (near 1 and 2.6 AU, respectively). Under these conditions, growth, rather than erosion, will occur only by collisions of bodies of nearly the same mass. There will be essentially no gravitational focusing between bodies less than 10(22) to 10(25) g, allowing growth of planetary embryos in the terrestrial planet region to proceed in a slower nonrunaway fashion. The environment in the asteroid belt will be even more forbidding and it is uncertain whether even the severely depleted present asteroid belt could form under these conditions. The perturbations of Jupiter and Saturn are quite sensitive to their semi-major axes and decrease when the planets' heliocentric distances are increased to allow for protoplanet migration. It is possible, though not clearly demonstrated, that this could produce a depleted asteroid belt but permit formation of a system of terrestrial planet embryos on a approximately 10(6)-year timescale, initially by nonrunaway growth and transitioning to runaway growth after approximately 10(5) years. The calculations reported here are valid under the condition that the relative velocities of the bodies are determined only by Jupiter and Saturn perturbations and by gas drag, with no mutual perturbations between planetesimals. If, while subject to these conditions, the bodies become large enough for their mutual perturbations to influence their velocity and size evolution significantly, the problem becomes much more complex. This problem is under investigation.

Kortenkamp, S. J.; Wetherill, G. W.

2000-01-01

85

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  

NASA Astrophysics Data System (ADS)

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.

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

2012-10-01

86

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

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.

Chang, Yu-Ling; Gu, Pin-Gao [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Bodenheimer, Peter H. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)

2012-10-01

87

The HARPS search for southern extra-solar planets I. HD330075 b: a new 'hot Jupiter'  

E-print Network

We report on the first extra-solar planet discovered with the brand new HARPS instrument. The planet is a typical 'hot Jupiter' with m2sini = 0.62 MJup and an orbital period of 3.39 days, but from the photometric follow-up of its parent star HD330075 we can exclude the presence of a transit. The induced radial-velocity variations exceed 100 m/s in semi-amplitude and are easily detected by state-of-the-art spectro-velocimeters. Nevertheless, the faint magnitude of the parent star (V = 9.36) benefits from the efficient instrument: With HARPS less than 10 observing nights and 3 hours of total integration time were needed to discover the planet and characterize its orbit. The orbital parameters determined from the observations made during the first HARPS run in July 2003 have been confirmed by 7 additional observations carried out in February 2004. The bisector analysis and a photometric follow-up give no hint for activity-induced radial-velocity variations, indicating that the velocity curve is best explained by the presence of a low-mass companion to the star. In this paper we present a set of 21 measurements of excellent quality with weighted rms as low as 2.0 m/s. These measurements lead to a well defined orbit and consequently to the precise orbital parameters determination of the extra-solar planet HD330075b.

F. Pepe; M. Mayor; D. Queloz; W. Benz; X. Bonfils; F. Bouchy; G. Lo Curto; C. Lovis; D. Megevand; C. Moutou; D. Naef; G. Rupprecht; N. C. Santos; J. P. Sivan; D. Sosnowska; S. Udry

2004-05-13

88

Two from Space: UC Berkeley Astronomers Find Jupiter-sized Planet Around Nearby Star in Big Dipper  

NSDL National Science Digital Library

In other space and planetary news, researchers have found signs of a Jupiter-sized planet near one of the Big Dipper's stars. To learn more, check out the University of California Planet Search program's press release that contains astronomical data, a sky chart, and links.

2001-01-01

89

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

Microsoft Academic Search

There is no universally acknowledged criterion to distinguish brown dwarfs\\u000afrom planets. Numerous studies have used or suggested a definition based on an\\u000aobject's mass, taking the ~13-Jupiter mass (M_J) limit for the ignition of\\u000adeuterium. Here, we investigate various deuterium-burning masses for a range of\\u000amodels. We find that, while 13 M_J is generally a reasonable rule of thumb,

David S. Spiegel; Adam Burrows; John A. Milsom

2010-01-01

90

ExtraSolar Planets Finding Extrasolar Planets. I  

E-print Network

close to the star. #12;Orbits Planets do not orbit the Sun - they both orbit the center of mass Planets. III Transits Six planets have been found by transits. This requires an edge-on orbit. JupiterExtraSolar Planets #12;Finding Extrasolar Planets. I Direct Searches Direct searches are difficult

Walter, Frederick M.

91

A Mass Function Constraint on Extrasolar Giant Planet Evaporation Rates  

E-print Network

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 mass function for such highly-irradiated EGPs agrees quantitatively with the M^{-1} law, implying that the mass function for EGPs is preserved despite migration to small orbital radii. Unless there is a remarkable compensation of mass-dependent orbital migration for mass-dependent 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.

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

2007-02-09

92

Jupiter  

NSDL National Science Digital Library

This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. An artist's conception of Jupiter's magnetic field as it is stretched out by the solar wind is also featured. The images are accompanied by a brief description and history, some statistical facts, and a list of significant dates in the exploration of Jupiter.

93

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

NASA Astrophysics Data System (ADS)

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.

Mosqueira, Ignacio; Lichtig, Ryan

2014-11-01

94

The lowest mass giant planet ever imaged around a star  

NASA Astrophysics Data System (ADS)

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.

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

95

Discovery of 18 Jupiter mass RV companion orbiting the brown dwarf candidate ChaHa8  

E-print Network

We report the discovery of a 16-20 Jupiter mass radial velocity companion around the very young (3 Myr) brown dwarf candidate ChaHa8. Based on high-resolution echelle spectra of ChaHa8 taken between 2000 and 2007 with UVES at the VLT, a companion was detected through RV variability with a semi-amplitude of 1.6 km/s. A Kepler fit to the data yields an orbital period of the companion of 1590 days and an eccentricity of e=0.49. A companion minimum mass M2sin i between 16 and 20 Jupiter masses is derived when using model-dependent mass estimates for the primary. The mass ratio M2/M1 might be as small as 0.2 and, with a probability of 87%, it is less than 0.4. ChaHa8 harbors most certainly the lowest mass companion detected so far in a close (~1 AU) orbit around a brown dwarf or very low-mass star. From the uncertainty in the orbit solution, it cannot completely be ruled out that the companion has a mass in the planetary regime. Its discovery is in any case an important step towards RV planet detections around BDs. Further, ChaHa8 is the fourth known spectroscopic brown dwarf or very low-mass binary system with an RV orbit solution and the second known very young one.

Viki Joergens; Andre Mueller

2007-10-12

96

16-20 Jupiter mass RV companion orbiting the brown dwarf candidate ChaHa8  

E-print Network

We report the discovery of a 16-20 Jupiter mass radial velocity companion around the very young (~3 Myr) brown dwarf candidate ChaHa8 (M5.75-M6.5). Based on high-resolution echelle spectra of ChaHa8 taken between 2000 and 2007 with UVES at the VLT, a companion was detected through RV variability with a semi-amplitude of 1.6 km/s. A Kepler fit to the data yields an orbital period of the companion of 1590 days and an eccentricity of e=0.49. A companion minimum mass M2sini between 16 and 20 Jupiter masses is derived when using model-dependent mass estimates for the primary. The mass ratio q= M2/M1 might be as small as 0.2 and, with a probability of 87%, it is less than 0.4. ChaHa8 harbors most certainly the lowest mass companion detected so far in a close (~ 1 AU) orbit around a brown dwarf or very low-mass star. From the uncertainty in the orbit solution, it cannot completely be ruled out that the companion has a mass in the planetary regime. Its discovery is in any case an important step towards RV planet detections around BDs. Further, ChaHa8 is the fourth known spectroscopic brown dwarf or very low-mass binary system with an RV orbit solution and the second known very young one.

V. Joergens; A. Mueller

2007-07-25

97

The potential for Earth-mass planet formation around brown dwarfs  

E-print Network

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.

Matthew J. Payne; Giuseppe Lodato

2007-09-05

98

On the formation time scale and core masses of gas giant planets  

E-print Network

Numerical simulations show that the migration of growing planetary cores may be dominated by turbulent fluctuations in the protoplanetary disk, rather than by any mean property of the flow. We quantify the impact of this stochastic core migration on the formation time scale and core mass of giant planets at the onset of runaway gas accretion. For standard Solar Nebula conditions, the formation of Jupiter can be accelerated by almost an order of magnitude if the growing core executes a random walk with an amplitude of a few tenths of an au. A modestly reduced surface density of planetesimals allows Jupiter to form within 10 Myr, with an initial core mass below 10 Earth masses, in better agreement with observational constraints. For extrasolar planetary systems, the results suggest that core accretion could form massive planets in disks with lower metallicities, and shorter lifetimes, than the Solar Nebula.

W. K. M. Rice; Philip J. Armitage

2003-10-07

99

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

SciTech Connect

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.

Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard; Kolbl, Rea [B-20 Hearst Field Annex, Astronomy Department, University of California, Berkeley, Berkeley, CA 94720 (United States); Rowe, Jason F.; Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fortney, Jonathan J.; Miller, Neil [Department of Astronomy and Astrophysics, University of California, Santa Cruz, 1156 High Street, 275 Interdisciplinary Sciences Building (ISB), Santa Cruz, CA 95064 (United States); Demory, Brice-Olivier; Seager, Sara [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06510-8101 (United States); Adams, Elisabeth R.; Dupree, Andrea K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Johnson, John Asher [California Institute of Technology, 1216 E. California Blvd., Pasadena, CA 91106 (United States); Horch, Elliott P. [Southern Connecticut State University, Department of Physics, 501 Crescent St., New Haven, CT 06515 (United States); Everett, Mark E. [National Optical Astronomy Observatory, 950 N. Cherry Ave, Tucson, AZ 85719 (United States); Fabrycky, Daniel C., E-mail: lweiss@berkeley.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637 (United States)

2013-05-01

100

A New Planet Around an M Dwarf: Revealing a Correlation Between Exoplanets and Stellar Mass  

E-print Network

We report precise Doppler measurements of GJ317 (M3.5V) that reveal the presence of a planet with a minimum mass Msini = 1.2 Mjup in an eccentric, 692.9 day orbit. GJ317 is only the third M dwarf with a Doppler-detected Jovian planet. The residuals to a single-Keplerian fit show evidence of a possible second orbital companion. The inclusion of an additional Jupiter-mass planet (P = 2700 days, Msini = 0.83 Mjup) improves the quality of fit significantly, reducing the rms from 12.5 m/s to 6.32 m/s. A false-alarm test yields a 1.1% probability that the curvature in the residuals of the single-planet fit is due to random fluctuations, lending additional credibility to the two-planet model. However, our data only marginally constrain a two-planet fit and further monitoring is necessary to fully characterize the properties of the second planet. To study the effect of stellar mass on Jovian planet occurrence we combine our samples of M stars, Solar-mass dwarfs and intermediate-mass subgiants. We find a positive correlation between stellar mass and the occurrence rate of Jovian planets within 2.5 AU; the former A-type stars in our sample are nearly 5 times more likely than the M dwarfs to harbor a giant planet. Our analysis shows that the correlation between Jovian planet occurrence and stellar mass remains even after accounting for the effects of stellar metallicity.

John A. Johnson; R. Paul Butler; Geoffrey W. Marcy; Debra A. Fischer; Steven S. Vogt; Jason T. Wright; Kathryn M. G. Peek

2007-07-16

101

Growth of Jupiter: Enhancement of core accretion by a voluminous low-mass envelope  

NASA Astrophysics Data System (ADS)

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 km in radius and orbits in a swarm of planetesimals whose initial radii range from 15 m to 50 km. The evolution of the swarm accounts for growth and fragmentation, viscous and gravitational stirring, and for drag-assisted migration and velocity damping. During this evolution, less than 9% of the mass is in planetesimals smaller than 1 km in radius; ?25% is in planetesimals with radii between 1 and 10 km; and ?7% is in bodies with radii larger than 100 km. Gas capture by the core substantially enhances the size-dependent cross-section of the planet for accretion of planetesimals. The calculation of dust opacity in the planet’s envelope accounts for coagulation and sedimentation of dust particles released as planetesimals are ablated. The calculation is carried out at an orbital semi-major axis of 5.2 AU and the initial solids’ surface density is 10 g cm-2 at that distance. The results give a core mass of nearly 7.3 Earth masses (M?) and an envelope mass of ?0.15 M? after about 4×105 years, at which point the envelope growth rate surpasses that of the core. The same calculation without the envelope yields a core of only about 4.4 M?.

D'Angelo, Gennaro; Weidenschilling, Stuart J.; Lissauer, Jack J.; Bodenheimer, Peter

2014-10-01

102

MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS  

SciTech Connect

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.

Batygin, Konstantin [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Stevenson, David J., E-mail: kbatygin@cfa.harvard.edu [Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)

2013-05-20

103

The HARPS search for southern extra-solar planets. I. HD 330075 b: A new ``hot Jupiter''  

Microsoft Academic Search

We report on the first extra-solar planet discovered with the brand new HARPS instrument. The planet is a typical ``hot Jupiter'' with m2 sin i=0.62 MJup and an orbital period of 3.39 days, but from the photometric follow-up of its parent star HD 330075 we can exclude the presence of a transit. The induced radial-velocity variations exceed 100 m s-1

F. Pepe; M. Mayor; D. Queloz; W. Benz; X. Bonfils; F. Bouchy; G. Lo Curto; C. Lovis; D. Mégevand; C. Moutou; D. Naef; G. Rupprecht; N. C. Santos; J.-P. Sivan; D. Sosnowska; S. Udry

2004-01-01

104

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

SciTech Connect

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.

Bakos, G. A.; Hartman, J. D.; Csubry, Z.; Penev, K. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Torres, G.; Beky, B.; Latham, D. W.; Bieryla, A.; Quinn, S.; Szklenar, T.; Esquerdo, G. A.; Noyes, R. W. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Buchhave, L. A. [Niels Bohr Institute, University of Copenhagen, DK-2100, Denmark, and Centre for Star and Planet Formation, Natural History Museum of Denmark, DK-1350 Copenhagen (Denmark); Kovacs, G. [Konkoly Observatory, Budapest (Hungary); Shporer, A. [LCOGT, 6740 Cortona Drive, Santa Barbara, CA (United States); Fischer, D. A. [Astronomy Department, Yale University, New Haven, CT (United States); Johnson, J. A. [California Institute of Technology, Department of Astrophysics, MC 249-17, Pasadena, CA (United States); Howard, A. W.; Marcy, G. W. [Department of Astronomy, University of California, Berkeley, CA (United States); Sato, B., E-mail: gbakos@astro.princeton.edu [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); and others

2012-07-15

105

The Mass of Dwarf Planet Eris  

Microsoft Academic Search

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 kilometers and a 15.774 ± 0.002 day

Michael E. Brown; Emily L. Schaller

2007-01-01

106

Type II Migration: Varying Planet Mass and Disc Viscosity  

E-print Network

This paper continues an earlier study of giant planet migration, examining the effect of planet mass and disc viscosity on the migration rate. We find that the migration rate of a gap-opening planet varies systematically with the planet's mass, as predicted in our earlier work. However, the variation with disc viscosity appears to be much weaker than expected.

Richard G. Edgar

2008-07-03

107

Obtaining the Mass and Radius of Extra-Solar Giant Planets  

NASA Technical Reports Server (NTRS)

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.

Castellano, Tim; Mead, Susan (Technical Monitor)

1998-01-01

108

Orbital Circularization of a Planet Accreting Disk Gas: The Formation of Distant Jupiters in Circular Orbits Based on a Core Accretion Model  

NASA Astrophysics Data System (ADS)

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.

Kikuchi, Akihiro; Higuchi, Arika; Ida, Shigeru

2014-12-01

109

WFIRST PLANET MASSES FROM MICROLENS PARALLAX  

SciTech Connect

I present a method using only a few ground-based observations of magnified microlensing events to routinely measure the parallaxes of WFIRST events if WFIRST is in an L2 orbit. This could be achieved for all events with A{sub max} > 30 using target-of-opportunity observations of select WFIRST events, or with a complementary, ground-based survey of the WFIRST field, which can push beyond this magnification limit. When combined with a measurement of the angular size of the Einstein ring, which is almost always measured in planetary events, these parallax measurements will routinely give measurements of the lens masses and hence the absolute masses of the planets. They can also lead to mass measurements for dark, isolated objects such as brown dwarfs, free-floating planets, and stellar remnants if the size of the Einstein ring is measured.

Yee, J. C., E-mail: jyee@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

2013-06-20

110

Transiting planets from WASP-South, Euler, and TRAPPIST. WASP-68 b, WASP-73 b, and WASP-88 b, three hot Jupiters transiting evolved solar-type stars  

NASA Astrophysics Data System (ADS)

Using the WASP transit survey, we report the discovery of three new hot Jupiters, WASP-68 b, WASP-73 b and WASP-88 b. The planet WASP-68 bhas a mass of 0.95 ± 0.03 MJup, a radius of 1.24-0.06+0.10 RJup, and orbits a V = 10.7 G0-type star (1.24 ± 0.03 M? 1.69-0.06+0.11 R?, Teff = 5911 ± 60 K) with a period of 5.084298 ± 0.000015 days. Its size is typical of hot Jupiters with similar masses. The planet WASP-73 bis significantly more massive (1.88-0.06+0.07 MJup) and slightly larger (1.16-0.08+0.12 RJup) than Jupiter. It orbits a V = 10.5 F9-type star (1.34-0.04+0.05 M?, 2.07-0.08+0.19 R?, Teff = 6036 ± 120 K) every 4.08722 ± 0.00022 days. Despite its high irradiation (~2.3 × 109 erg s-1 cm-2), WASP-73 b has a high mean density (1.20-0.30+0.26 ?Jup) that suggests an enrichment of the planet in heavy elements. The planet WASP-88 bis a 0.56 ± 0.08 MJuphot Jupiter orbiting a V = 11.4 F6-type star (1.45 ± 0.05 M?, 2.08-0.06+0.12 R?, Teff = 6431 ± 130 K) with a period of 4.954000 ± 0.000019 days. With a radius of 1.70-0.07+0.13 RJup, it joins the handful of planets with super-inflated radii. The ranges of ages we determine through stellar evolution modeling are 4.5-7.0 Gyr for WASP-68, 2.8-5.7 Gyr for WASP-73 and 1.8-4.3 Gyr for WASP-88. The star WASP-73 appears to be significantly evolved, close to or already in the subgiant phase. The stars WASP-68 and WASP-88 are less evolved, although in an advanced stage of core H-burning. Tables 1-3 are available in electronic form at http://www.aanda.orgThe photometric time-series used in this work are only 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/A143

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

2014-03-01

111

Jupiter  

NASA Astrophysics Data System (ADS)

Preface; 1. Introduction F. Bagenal, T. E. Dowling and W. B. McKinnon; 2. The origin of Jupiter J. I. Lunine, A. Corandini, D. Gautier, T. C. Owen and G. Wuchterl; 3. The interior of Jupiter T. Guillot, D. J. Stevenson, W. B. Hubbard and D. Saumon; 4. The composition of the atmosphere of Jupiter F. W. Taylor, S. K. Atreya, Th. Encrenaz, D. M. Hunten, P. G. J. Irwin and T. C. Owen; 5. Jovian clouds and haze R. A. West, K. H. Baines, A. J. Friedson, D. Banfield, B. Ragent and F. W. Taylor; 6. Dynamics of Jupiter's atmosphere A. P. Ingersoll, T. E. Dowling, P. J. Gierasch, G. S. Orton, P. L. Read, A. Sánchez-Lavega, A. P. Showman, A. A. Simon-Miller and A. R. Vasavada; 7. The stratosphere of Jupiter J. I. Moses, T. Fouchet, R. V. Yelle, A. J. Friedson, G. S. Orton, B. Bézard, P. Drossart, G. R. Gladstone, T. Kostiuk and T. A. Livengood; 8. Lessons from Shoemaker-Levy 9 about Jupiter and planetary impacts J. Harrington, I. de Pater, S. H. Brecht, D. Deming, V. Meadows, K. Zahnle and P. D. Nicholson; 9. Jupiter's thermosphere and ionosphere R. V. Yelle and S. Miller; 10. Jovian dust: streams, clouds and rings H. Krüger, M. Horányi, A. V. Krivov and A. L. Graps; 11. Jupiter's ring-moon system J. A. Burns, D. P. Simonelli, M. R. Showalter, D. P. Hamilton, C. C. Porco, H. Throop and L. W. Esposito; 12. Jupiter's outer satellites and trojans D. C. Jewitt, S. Sheppard and C. Porco; 13. Interior composition, structure and dynamics of the Galilean satellites G. Schubert, J. D. Anderson, T. Spohn and W. B. McKinnon; 14. The lithosphere and surface of Io A. S. McEwen, L. P. Keszthelyi, R. Lopes, P. M. Schenk and J. R. Spencer; 15. Geology of Europa R. Greeley, C. F. Chyba, J. W. Head III, T. B. McCord, W. B. McKinnon, R. T. Pappalardo and P. Figueredo; 16. Geology of Ganymede R. T. Pappalardo, G. C. Collins, J. W. Head III, P. Helfenstein, T. B. McCord, J. M. Moore, L. M. Procktor, P. M. Shenk and J. R. Spencer; 17. Callisto J. M. Moore, C. R. Chapman. E. B. Bierhaus, R. Greeley, F. C. Chuang, J. Klemaszewski, R. N. Clark, J. B. Dalton, C. A. Hibbitts, P. M. Schenk, J. R. Spencer and R. Wagner; 18. Ages and interiors: the cratering record of the Galilean satellites P. M. Schenk, C. R. Chapman, K. Zahnle and J. M. Moore; 19. Satellite atmospheres M. A. McGrath, E. Lellouch, D. F. Strobel, P. D. Feldman and R. E. Johnson; 20. Radiation effects on the surfaces of the Galilean satellites R. E. Johnson, R. W. Carlson, J. F. Cooper, C. Paranicas, M. H. Moore and M. C. Wong; 21. Magnetospheric interactions with satellites M. G. Kivelson, F. Bagenal, W. S. Kurth, F. M. Neubauer, C. Paranicas and J. Saur; 22. Plasma interactions of Io with its plasma torus J. Saur, F. M. Neubauer, J. E. P. Connerney, P. Zarka and M. G. Kivelson; 23. The Io neutral clouds and plasma torus N. Thomas, F. Bagenal, T. W. Hill and J. K. Wilson; 24. The configuration of Jupiter's magnetosphere K. K. Khurana, M. G. Kivelson, V. M. Vasyliunas, N. Krupp, J. Woch, A. Lagg, B. H. Mauk and W. S. Kurth; 25. Dynamics of the Jovian magnetosphere N. Krupp, V. M. Vasyliunas, J. Woch, A. Lagg, K. K. Khurana, M. G. Kivelson, B. H. Mauk, E. C. Roelof, D. J. Williams, S. M. Krimigis, W. S. Kurth, L. A. Frank and W. R. Paterson; 26. Jupiter's Aurora J. T. Clarke, D. Grodent, S. W. H. Cowley, E. J. Bunce, P. Zarka, J. E. P. Connerney and T. Satoh; 27. Jupiter's inner radiation belts S. J. Bolton, R. M. Thorne, S. Bourdarie, I. de Pater and B. Mauk; Appendix 1. Maps and spectra of Jupiter and the Galilean satellites J. R. Spencer, R. W. Carlson, T. L. Becker and J. S. Blue; Appendix 2. Planetary parameters J. W. Weiss; Index.

Bagenal, Fran; Dowling, Timothy E.; McKinnon, William B.

2007-03-01

112

Three-dimensional Calculations of High and Low-mass Planets Embedded in Protoplanetary Discs  

E-print Network

We analyse the non-linear, three-dimensional response of a gaseous, viscous protoplanetary disc to the presence of a planet of mass ranging from one Earth mass (1 M$_e$) to one Jupiter mass (1 M$_J$) by using the ZEUS hydrodynamics code. We determine the gas flow pattern, and the accretion and migration rates of the planet. The planet is assumed to be in a fixed circular orbit about the central star. It is also assumed to be able to accrete gas without expansion on the scale of its Roche radius. Only planets with masses $M \\gsim 0.1$ M$_J$ produce significant perturbations in the disc's surface density. The flow within the Roche lobe of the planet is fully three-dimensional. Gas streams generally enter the Roche lobe close to the disc midplane, but produce much weaker shocks than the streams in two-dimensional models. The streams supply material to a circumplanetary disc that rotates in the same sense as the planet's orbit. Much of the mass supply to the circumplanetary disc comes from non-coplanar flow. The ...

Bate, M R; Ogilvie, G I; Miller, K A

2003-01-01

113

HAT-P-44b, HAT-P-45b, and HAT-P-46b: Three Transiting Hot Jupiters in Possible Multi-planet Systems  

NASA Astrophysics Data System (ADS)

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 J, and radii of 1.24, 1.43, and 1.28 R J. The stellar hosts have masses of 0.94, 1.26, and 1.28 M ?. 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 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-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 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. 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. Keck time has been granted by NOAO (A284Hr) and NASA (N154Hr, N108Hr).

Hartman, J. D.; Bakos, G. Á.; Torres, G.; Kovács, G.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Latham, D. W.; Bieryla, A.; Buchhave, L. A.; Bhatti, W.; Béky, B.; Csubry, Z.; Penev, K.; de Val-Borro, M.; Noyes, R. W.; Fischer, D. A.; Esquerdo, G. A.; Everett, M.; Szklenár, T.; Zhou, G.; Bayliss, D.; Shporer, A.; Fulton, B. J.; Sanchis-Ojeda, R.; Falco, E.; Lázár, J.; Papp, I.; Sári, P.

2014-06-01

114

Mass-loss rates of "hot-Jupiter" exoplanets with various types of gaseous envelopes  

NASA Astrophysics Data System (ADS)

According to the compuations results obtained by Bisikalo et al. (2013) for the gas-dynamical effect of stellar winds on exoplanet atmospheres, three types of gaseous envelopes can form around hot Jupiters: closed, quasi-closed, and open. The type of envelope that forms depends on the position of the frontal collision point (where the dynamical pressure of the wind is equal to the pressure of the surrounding atmosphere) relative to the Roche-lobe boundaries. Closed envelopes are formed around planets whose atmospheres lie completely within their Roche lobes. If the frontal collision point is located outside the Roche lobe, the atmospheric material begins to flow out through the Lagrangian points L1 and L2, which can result in the formation of quasi-closed (if the dynamical pressure of the stellar wind stops the outflow through L1) or open gaseous envelopes. The example of the typical hot Jupiter HD 209458b is considered for four sets of atmospheric parameters, to determine the mass-loss rates for the different types of envelopes arising with these parameters. The mass-loss rates based on the modeling results were estimated to be ? ? 109 g/s for a closed atmosphere, ? ? 3 × 109 g/s for a quasi-closed atmosphere, and ? ? 3 × 1010 g/s for an open atmosphere. The matter in the closed and quasi-closed atmospheres flows out mainly through L2, and the matter in open envelopes primarily through L1.

Cherenkov, A. A.; Bisikalo, D. V.; Kaigorodov, P. V.

2014-10-01

115

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

SciTech Connect

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.

Matter, A.; Lopez, B.; Lagarde, S. [Laboratoire Fizeau, UMR 6525, UNS-Observatoire de la cote d'azur, BP 4229, F-06304 Nice Cedex 4 (France); Danchi, W. C. [NASA/GSFC, Greenbelt, MD 20771 (United States); Robbe-Dubois, S.; Petrov, R. G. [Laboratoire Fizeau, UMR 6525, UNS-Observatoire de la cote d'azur, 06108 Nice Cedex 02 (France); Navarro, R., E-mail: matter@oca.e [NOVA-ASTRON, P.O. Box 2, 7990 AA Dwingeloo (Netherlands)

2009-12-01

116

Nebular gas drag and planetary accretion with eccentric high-mass planets  

NASA Astrophysics Data System (ADS)

Aims: We investigate the dynamics of pebbles immersed in a gas disk interacting with a planet on an eccentric orbit. The model has a prescribed gap in the disk around the location of the planetary orbit, as is expected for a giant planet with a mass in the range of 0.1-1 Jupiter masses. The pebbles with sizes in the range of 1 cm to 3 m are placed in a ring outside of the giant planet orbit at distances between 10 and 30 planetary Hill radii. The process of the accumulation of pebbles closer to the gap edge, its possible implication for the planetary accretion, and the importance of the mass and the eccentricity of the planet in this process are the motivations behind the present contribution. Methods: We used the Bulirsch-Stoer numerical algorithm, which is computationally consistent for close approaches, to integrate the Newtonian equations of the planar (2D), elliptical restricted three-body problem. The angular velocity of the gas disk was determined by the appropriate balance between the gravity, centrifugal, and pressure forces, such that it is sub-Keplerian in regions with a negative radial pressure gradient and super-Keplerian where the radial pressure gradient is positive. Results: The results show that there are no trappings in the 1:1 resonance around the L4 and L5 Lagrangian points for very low planetary eccentricities (e2 < 0.07). The trappings in exterior resonances, in the majority of cases, are because the angular velocity of the disk is super-Keplerian in the gap disk outside of the planetary orbit and because the inward drift is stopped. Furthermore, the semi-major axis location of such trappings depends on the gas pressure profile of the gap (depth) and is a = 1.2 for a planet of 1 MJ. A planet on an eccentric orbit interacts with the pebble layer formed by these resonances. Collisions occur and become important for planetary eccentricity near the present value of Jupiter (e2 = 0.05). The maximum rate of the collisions onto a planet of 0.1 MJ occurs when the pebble size is 37.5 cm ? s < 75 cm; for a planet with the mass of Jupiter, it is15 cm ? s < 30 cm. The accretion stops when the pebble size is less than 2 cm and the gas drag dominates the motion. Appendices are available in electronic form at http://www.aanda.org

Chanut, T. G. G.; Winter, O. C.; Tsuchida, M.

2013-04-01

117

The HARPS search for southern extra-solar planets I. HD330075 b: a new 'hot Jupiter'  

Microsoft Academic Search

We report on the first extra-solar planet discovered with the brand new HARPS\\u000ainstrument. The planet is a typical 'hot Jupiter' with m2sini = 0.62 MJup and\\u000aan orbital period of 3.39 days, but from the photometric follow-up of its\\u000aparent star HD330075 we can exclude the presence of a transit. The induced\\u000aradial-velocity variations exceed 100 m\\/s in semi-amplitude

F. Pepe; M. Mayor; D. Queloz; W. Benz; X. Bonfils; F. Bouchy; G. Lo Curto; C. Lovis; D. Megevand; C. Moutou; D. Naef; G. Rupprecht; N. C. Santos; J. P. Sivan; D. Sosnowska; S. Udry

2004-01-01

118

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

E-print Network

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.

Stephen L. Adler

2008-08-20

119

The Minimum Gap-opening Planet Mass in an Irradiated Circumstellar Accretion Disk  

E-print Network

We consider the minimum mass planet, as a function of radius, that is capable of opening a gap in an $\\alpha$-accretion disk. We estimate that a half Jupiter mass planet can open a gap in a disk with accretion rate $\\dot M \\la 10^{-8} M_\\odot$/yr for viscosity parameter $\\alpha =0.01$, and Solar mass and luminosity. The minimum mass is approximately proportional to $\\dot M^{0.48} \\alpha^{0.8} M_*^{0.42} L_*^{-0.08}$. This estimate can be used to rule out the presence of massive planets in gapless accretion disks. We identify two radii at which an inwardly migrating planet may become able to open a gap and so slow its migration; the radius at which the heating from viscous dissipation is similar to that from stellar radiation in a flared disk, and the radius at which the disk has optical depth order 1 in a self-shadowed disk. If a gap opening planet cuts off disk accretion allowing the formation of a central hole or clearing in the disk then we would estimate that the clearing radius would approximately be proportional to the stellar mass.

Richard G. Edgar; Alice C. Quillen; Jaehong Park

2007-05-23

120

50&100YEARSAGO EXTRASOLAR PLANETS  

E-print Network

be harmful to the bulk of complex life forms on Earth. Jupiter's methane, meanwhile, isphotochemicalinorigin emission from methane in the upper atmosphere of a Jupiter-like extrasolar planet. The first extrasolar the discovery of fluorescent emission from methane in the upper atmosphere of a nearby, Jupiter-mass extrasolar

Royer, Dana

121

Clouds in Low-mass, Low-density Planets  

NASA Astrophysics Data System (ADS)

The Kepler Space Telescope has revealed huge populations of low-mass, low-density planets, but their compositions remain elusive. For example, the density of GJ 1214b is consistent with either a water-world with a water atmosphere or a rock-iron core with a H/He envelope. Other super-Earths must contain hydrogen and helium to match their observed masses and radii. To understand this population of objects, we must be able to characterize their compositions through spectroscopy. The formation of clouds in exoplanet atmospheres significantly changes their observable spectra. For exoplanets, the opacity of hazes or clouds has been invoked as a possible explanation for the observed flat transmission spectrum of transiting super-Earth GJ 1214b as well as for the strong Rayleigh scattering feature in HD 189733b, the best-studied hot Jupiter. Here, we examine the effect of clouds on low-mass, low-density exoplanet spectra. We include the condensates that are present in chemical equilibrium for objects at these temperatures (500-900 K) which include minerals like sulfides and alkali salts. The most important of these clouds are sodium sulfide, potassium chloride, and zinc sulfide. These clouds should be most prominent at low surface gravity, strongly super-solar atmospheric abundances, and at the slant viewing geometry appropriate for transits. Hence they could be quite important for affecting the transmission spectra of cool low density super-Earth and Neptune-class planets. Another class of clouds may also dramatically alter the spectra of irradiated planets: photochemical hazes. We additionally include a hydrocarbon haze layer similar to the tholin haze in Titan’s atmosphere. We calculate the location and density of the haze layer using photochemical models from Kempton et al. 2012. We present new results that show that for enhanced metallicity atmospheres, either the clouds that form in equilibrium or a hydrocarbon haze layer could become sufficiently optically thick to reproduce the observations of GJ 1214b. We also present predictions for other low-mass, low-density exoplanets which will be targets of future observational campaigns: HD 97658b and GJ 3470b.

Morley, Caroline; Fortney, J.; Marley, M.; Kempton, E.; Visscher, C.; Zahnle, K.

2013-10-01

122

A Spitzer Five-band Analysis of the Jupiter-sized Planet TrES-1  

NASA Astrophysics Data System (ADS)

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+0.015 -0.031, 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.

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

2014-12-01

123

Jupiter - friend or foe? II: the Centaurs  

Microsoft Academic Search

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

Jonti Horner; B. W. Jones

2009-01-01

124

Mass Measurements for Microlens Planets with WFIRST/AFTA  

NASA Astrophysics Data System (ADS)

Unlike ground-based surveys, WFIRST/AFTA will be able to systematically measure masses of the lens stars (and hence their planets) for a large number of microlensing events. I will review the methods WFIRST/AFTA will use to measure masses (detection of lens light, microlens parallax, and astrometric microlensing) and present a few examples of how these techniques have been applied to date. These mass measurements are important for understanding the planet population and characterizing structures in the planet mass function beyond the snow line. In addition, they can be used to measure the stellar mass function from black holes to brown dwarfs and unambiguously identifying free-floating planets.

Yee, Jennifer C

2014-06-01

125

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

NASA Astrophysics Data System (ADS)

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).

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

126

Exceptional Stars Origins, Companions, Masses and Planets  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

127

Voyager 2 Jupiter Eruption Movie  

NASA Technical Reports Server (NTRS)

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.

2000-01-01

128

An MHD Model for Hot Jupiter Upper Atmospheres: Mass/Angular  

E-print Network

An MHD Model for Hot Jupiter Upper Atmospheres: Mass/Angular Momentum Loss & Transits George B. Trammell University of Virginia Collaborators: Phil Arras, Zhi-Yun Li #12;Introduction · hot Jupiters M (Yelle 2004) P = 1 bar ­ 1 mbar: optical/NIR continuum (103 K) e.g., H2, H2O, He, CH4 GCMs, weather, day

Johnson, Robert E.

129

Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing  

SciTech Connect

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.

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

130

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)

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.

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

2014-11-01

131

Magnetically controlled mass-loss from extrasolar planets in close orbits  

NASA Astrophysics Data System (ADS)

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.

Owen, James E.; Adams, Fred C.

2014-11-01

132

Dynamical corotation torques on low-mass planets  

E-print Network

We study torques on migrating low-mass planets in locally isothermal discs. Previous work on low-mass planets generally kept the planet on a fixed orbit, after which the torque on the planet was measured. In addition to these static torques, when the planet is allowed to migrate it experiences dynamical torques, which are proportional to the migration rate and whose sign depends on the background vortensity gradient. We show that in discs a few times more massive than the Minimum Mass Solar Nebula, these dynamical torques can have a profound impact on planet migration. Inward migration can be slowed down significantly, and if static torques lead to outward migration, dynamical torques can take over, taking the planet beyond zero-torque lines set by saturation of the corotation torque in a runaway fashion. This means the region in non-isothermal discs where outward migration is possible can be larger than what would be concluded from static torques alone.

Paardekooper, Sijme-Jan

2014-01-01

133

A historical interpretation of the study of the visible cloud morphology on the planet Jupiter: 1610-1878  

SciTech Connect

The majority of the literature discussing the perceived physical appearance of Jupiter published prior to 1878 has been examined in order to determine to what extent observations were biased by technical limitations and preconceptions of their day and, in lieu of these, how useful this body of work is in characterizing the behavior of the Jovian upper atmosphere over the last three hundred years. The biographies of the historical observers; their instrumentation, available viewing conditions, and observational techniques; their means of communication with their fellows; and the primary interpretive references available to their libraries have been investigated in order to attempt to explain discrepancies and agreement between what was reported in pre-photographic times and what is presently seen. It has been found that nearly all of the prominent feature-types found on Jupiter today existed during the nineteenth century and, in some cases, earlier. The longevity and frequency of the appearance of features can not be accurately determined from the time before objective surveys of the planet were organized. This is because, during each apparition of Jupiter, nonprofessional part-time observers, working independently chose to use their finite time and resources to follow the progress of specific discoveries on its disk to the exclusion of the rest of the planet.

Hockey, T.A.

1988-01-01

134

Atmospheric Mass Loss During Planet Formation  

E-print Network

We quantify the atmospheric mass loss during planet formation by examining the contributions to atmospheric loss from both giant impacts and planetesimal accretion. Giant impacts cause global motion of the ground. Using analytic self-similar solutions and full numerical integrations we find (for isothermal atmospheres with adiabatic index ($\\gamma=5/3$) that the local atmospheric mass loss fraction for ground velocities $v_g \\sqrt{2} \\rho_0 (\\pi h R)^{3/2}$ (25~km for the current Earth), are able to eject all the atmosphere above the tangent plane of the impact site, which is $h/2R$ of the whole atmosphere, where $h$, $R$ and $\\rho_0$ are the atmospheric scale height, radius of the target, and its atmospheric density at the ground. 2) Smaller impactors, but above $m>4 \\pi \\rho_0 h^3$ (1~km for the current Earth) are only able to eject a fraction of the atmospheric mass above the tangent plane. We find that the most efficient impactors (per unit impactor mass) for atmospheric loss are planetesimals just above...

Schlichting, Hilke; Yalinewich, Almog

2014-01-01

135

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

PubMed

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

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

136

WASP-22 b: A TRANSITING 'HOT JUPITER' PLANET IN A HIERARCHICAL TRIPLE SYSTEM  

SciTech Connect

We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T{sub eff} = 6000 {+-} 100 K, [Fe/H] = -0.05 {+-} 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M{sub p} = 0.56 {+-} 0.02M{sub Jup} and a radius R{sub p} = 1.12 {+-} 0.04R{sub Jup}. In addition, there is a linear trend of 40 m s{sup -1} yr{sup -1} in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.

Maxted, P. F. L.; Anderson, D. R.; Hellier, C.; Smalley, B.; Wilson, D. M.; Bentley, S. J.; Cegla, H. [Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom); Gillon, M.; Queloz, D.; Triaud, A. H. M. J.; Mayor, M.; Pepe, F. [Observatoire de Geneve, Universite de Geneve, 51 Chemin des Maillettes, 1290 Sauverny (Switzerland); West, R. G. [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Collier Cameron, A.; Enoch, B.; Hebb, L.; Horne, K.; Parley, N. [School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS (United Kingdom); Irwin, J. [Department of Astronomy, Harvard University, 60 Garden Street, MS 10, Cambridge, MA 02138 (United States); Lister, T. A. [Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States)

2010-12-15

137

The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars  

NASA Astrophysics Data System (ADS)

Context. In 1992 we began a precision radial velocity survey for planets around solar-like stars with the Coudé Echelle Spectrograph and the Long Camera (CES LC) at the 1.4 m telescope in La Silla (Chile) resulting in the discovery of the planet ? Hor b. We have continued the survey with the upgraded CES Very Long Camera (VLC) and the HARPS spectrographs, both at the 3.6 m telescope, until 2007. Aims: In this paper we present additional radial velocities for 31 stars of the original sample with higher precision. The observations cover a time span of up to 15 years and permit a search for Jupiter analogues. Methods: The survey was carried out with three different instruments/instrument configurations using the iodine absorption cell and the ThAr methods for wavelength calibration. We combine the data sets and perform a joint analysis for variability, trends, and periodicities. We compute Keplerian orbits for companions and detection limits in case of non-detections. Moreover, the HARPS radial velocities are analysed for correlations with activity indicators (CaII H&K and cross-correlation function shape). Results: We achieve a long-term RV precision of 15 m/s (CES+LC, 1992-1998), 9 m/s (CES+VLC, 1999-2006), and 2.8 m/s (HARPS, 2003-2009, including archive data), respectively. This enables us to confirm the known planetary signals in ? Hor and HR 506 as well as the three known planets around HR 3259. A steady RV trend for ? Ind A can be explained by a planetary companion and calls for direct imaging campaigns. On the other hand, we find previously reported trends to be smaller for ? Hyi and not present for ? Men. The candidate planet ? Eri b was not detected despite our better precision. Also the planet announced for HR 4523 cannot be confirmed. Long-term trends in several of our stars are compatible with known stellar companions. We provide a spectroscopic orbital solution for the binary HR 2400 and refined solutions for the planets around HR 506 and ? Hor. For some other stars the variations could be attributed to stellar activity, as e.g. the magnetic cycle in the case of HR 8323. Conclusions: The occurrence of two Jupiter-mass planets in our sample is in line with the estimate of 10% for the frequency of giant planets with periods smaller than 10 yr around solar-like stars. We have not detected a Jupiter analogue, while the detections limits for circular orbits indicate at 5 AU a sensitivity for minimum mass of at least 1MJup (2MJup) for 13% (61%) of the stars. Based on observations collected at the European Southern Observatory, La Silla Chile, ESO programmes 50.7-0095, 51.7-0054, 52.7-0002, 53.7-0064, 54.E-0424, 55.E-0361, 56.E-0490, 57.E-0142, 58.E-0134, 59.E-0597, 60.E-0386, 61.E-0589, 62.L-0490, 64.L-0568, 66.C-0482, 67.C-0296, 69.C-0723, 70.C-0047, 71.C-0599, 072.C-0513, 073.C-0784, 074.C-0012, 076.C-0878, 077.C-0530, 078.C-0833, 079.C-0681. Also based on data obtained from the ESO Science Archive Facility.Appendices are available in electronic form at http://www.aanda.orgTables of the radial velocities, bisector spans, and log R'_HK are 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/552/A78

Zechmeister, M.; Kürster, M.; Endl, M.; Lo Curto, G.; Hartman, H.; Nilsson, H.; Henning, T.; Hatzes, A. P.; Cochran, W. D.

2013-04-01

138

Jupiter - friend or foe?  

NASA Astrophysics Data System (ADS)

Throughout both popular science and academia, there is a pervasive belief that Jupiter has acted as a celestial shield, reducing the impact rate on the Earth, and making the planet a significantly more conducive site for the evolution and survival of life. This old idea has, however, undergone little detailed scrutiny. In the first of a series of studies aimed at a better understanding of this idea, we examine the variation in the impact rate on the Earth which results from bodies moving inwards from the Edgeworth- Kuiper belt as a function of the mass of a giant planet in Jupiter's orbit. The results are not entirely what would be expected under the "Jupiter Shield" paradigm.

Horner, J.; Jones, B. W.

2007-08-01

139

Stability of Earth-Mass Planets in the Habitable Zones of Extrasolar Planetary Systems  

E-print Network

Kumar Kopparapu Dept. of Geosciences, College of Earth and Mineral Science Over 500 planets orbiting be influenced by the remaining companions in the system. Just like Jupiter affects the orbits of planets in our solar system, giant planets in extrasolar planetary systems also influence the orbits of Earth

Bjørnstad, Ottar Nordal

140

Jupiter: Satellites  

Microsoft Academic Search

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

P. Geissler

2003-01-01

141

HAT-P-34b-HAT-P-37b: Four Transiting Planets More Massive than Jupiter Orbiting Moderately Bright Stars  

NASA Astrophysics Data System (ADS)

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 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 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. 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. Keck time has been granted by NOAO (A289Hr) and NASA (N167Hr and N029Hr). Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

Bakos, G. Á.; Hartman, J. D.; Torres, G.; Béky, B.; Latham, D. W.; Buchhave, L. A.; Csubry, Z.; Kovács, G.; Bieryla, A.; Quinn, S.; Szklenár, T.; Esquerdo, G. A.; Shporer, A.; Noyes, R. W.; Fischer, D. A.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Sato, B.; Penev, K.; Everett, M.; Sasselov, D. D.; F?rész, G.; Stefanik, R. P.; Lázár, J.; Papp, I.; Sári, P.

2012-07-01

142

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

E-print Network

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...

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

143

Orbital Evolution and Migration of Giant Planets: Modeling Extrasolar Planets  

E-print Network

Giant planets in circumstellar disks can migrate inward from their initial (formation) positions. Radial migration is caused by inward torques between the planet and the disk; by outward torques between the planet and the spinning star; and by outward torques due to Roche lobe overflow and consequent mass loss from the planet. We present self-consistent numerical considerations of the problem of migrating giant planets. Summing torques on planets for various physical parameters, we find that Jupiter-mass planets can stably arrive and survive at small heliocentric distances, thus reproducing observed properties of some of the recently discovered extra-solar planets. Inward migration timescales can be approximately equal to or less than disk lifetimes and star spindown timescales. Therefore, the range of fates of massive planets is broad, and generally comprises three classes: (I) planets which migrate inward too rapidly and lose all their mass; (II) planets which migrate inward, lose some but not all of their mass, and survive in very small orbits; and (III) planets which do not lose any mass. Some planets in Class III do not migrate very far from their formation locations. Our results show that there is a wide range of possible fates for Jupiter-mass planets for both final heliocentric distance and final mass.

D. E. Trilling; W. Benz; T. Guillot; J. I. Lunine; W. B. Hubbard; A. Burrows

1998-01-28

144

Planetary Populations in the Mass-Period Diagram: A Statistical Treatment of Exoplanet Formation and the Role of Planet Traps  

NASA Astrophysics Data System (ADS)

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 * <= 0.7 M ?).

Hasegawa, Yasuhiro; Pudritz, Ralph E.

2013-11-01

145

XVI. CoRoT-13b: a dense hot Jupiter in transit around a star with solar metallicity and super-solar lithium content  

Microsoft Academic Search

We announce the discovery of the transiting planet CoRoT-13b. Ground based follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the planet was measured with the HARPS spectrograph and the properties of the host star were obtained analyzing Keck data. It is a hot Jupiter-like planet with an orbital period of 4.04 days, 1.3 Jupiter masses, 0.9 Jupiter

J. Cabrera; H. Bruntt; M. Ollivier; R. F. D ´ iaz; S. Aigrain; R. Alonso; J.-M. Almenara; M. Auvergne; A. Baglin; P. Barge; A. S. Bonomo; P. Bord; F. Bouchy; L. Carone; S. Carpano; M. Deleuil; H. J. Deeg; R. Dvorak; A. Erikson; S. Ferraz-Mello; M. Fridlund; D. Gandolfi; J.-C. Gazzano; M. Gillon; E. W. Guenther; T. Guillot; A. Hatzes; M. Havel; G. Hebrard; L. Jorda; A. L ´ eger; A. Llebaria; H. Lammer; C. Lovis; T. Mazeh; C. Moutou; D. Queloz; H. Rauer; D. Rouan; A. Santerne; J. Schneider; B. Tingley; R. Titz-Weider; G. Wuchterl

2010-01-01

146

1. How are the rocky core masses of Jupiter and Saturn determined? 2. What are the most accurate values today?  

E-print Network

1. How are the rocky core masses of Jupiter and Saturn determined? 2. What are the most accurate Jupiter a core - and if so does it matter? Edwin Kite AY 250 1 Feb 2008 #12;0 0 #12;To this level of approximation Jupiter and Saturn can be modelled as H/He mixtures; however, ZJup ~ 3 x Zsolar , and ZSat ~ 4

Kite, Edwin

147

Jupiter - Friend or Foe?  

NASA Astrophysics Data System (ADS)

It has long been believed that the planet Jupiter has played a beneficial role in the development of life on the Earth, acting as a shield from objects which would otherwise go on to significantly raise the impact flux experienced by our planet. Without Jupiter, the story goes, the Earth would have experienced a far greater number of impacts, making it far less hospitable to burgeoning life. In an on-going series of separate studies[1,2], we have examined the effects of varying the mass of Jupiter on the impact flux that the Earth would experience from Near-Earth Objects sourced from the Asteroid belt, short-period comets sourced from the Edgeworth-Kuiper belt, and long-period comets sourced from the Oort cloud. The results are remarkable - it seems that, far from being a shield, Jupiter actually acts to increase the impact flux experienced by the Earth over that which would be expected without the planet. Still more surprising, in the cases of the asteroids and Edgeworth-Kuiper belt objects, it seems that a Jupiter around 0.2 times the mass of "our Jupiter" would be even more threatening, sending a still greater number of objects our way. In order to simulate such disparate populations, different approaches to population construction were needed. The asteroidal and short-period comet populations each contained 100,000 test particles, moving on orbits typical of their class. The asteroids were initially distributed between 2 and 4 AU, with orbits of varying eccentricity and inclination, with number density varying as a function of semi-major axis. The short-period cometary flux was obtained through simulation of a population based on the subset of known Centaurs and Scattered Disk Objects which are Neptune-crossing, and have perihelia beyond the orbit of Uranus. These objects are the parents of the short-period comets, and were chosen since they are a population beyond the current influence of the planet Jupiter. Since our goal was to study the effect of Jupiter's mass on the impact flux at the Earth from the two populations, we followed our 100,000 particle populations for 10 million years, under the influence of the giant planets. Each particle was followed until it either hit something, or was ejected from the system. In this manner, we were able to follow the flux of objects onto the Earth as a function of time. The simulations were repeated over a wide range of Jupiter masses, with all other variables being held constant, allowing us to observe the variations in impact flux as a function of Jovian mass. In the cases of the asteroids and the short-period comets, Jupiter was observed to significantly modify the impact flux which would be experienced by the planet Earth. It was immediately obvious, however, that the old idea that Jupiter shields us from impacts no longer holds. For both of these populations, the lowest impact rates were experienced when the Jupiter-like planet in the system had the lowest mass, rose rapidly to a peak flux at around 0.2 Jupiter masses, before falling away more slowly. Therefore, for the asteroids and short-period comets, it seems that our Jupiter does offer some shielding, when compared to the case where the planet has a mass of around 0.2 MJ, but, compared to the scenario where no Jupiter is present at all (or the Jupiter in question has very low mass), Jupiter actually acts to increase the Earth-bound flux. Simulations are currently underway with the goal of analysing the effects of Jupiter's mass on the impact flux from the long-period comets (deflected inward towards the Earth from the Oort cloud). Further into the future, we intend to study the effects of Jovian position of the impact flux, with the goal of answering, once and for all, the question - "Jupiter - Friend or Foe?".

Horner, J.; Jones, B. W.

2008-09-01

148

Exotic Earths: Forming Habitable Worlds with Giant Planet Migration  

E-print Network

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.

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

2006-09-08

149

Erratum: The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 d orbit around a late F star  

NASA Astrophysics Data System (ADS)

We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope (UKIRT) in August 2007. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J ~ 16 were constructed for ~60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01 +- 0.35 Mj and a planetary radius of 1.49+0.16-0.18 Rj. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Mj. The high irradiation from the host star ranks the planet in the pM class.

Cappetta, M.; Saglia, R. P.; Birkby, J. L.; Koppenhoefer, J.; Pinfield, D. J.; Hodgkin, S. T.; Cruz, P.; Kovács, G.; Sip?cz, B.; Barrado, D.; Nefs, B.; Pavlenko, Y. V.; Fossati, L.; del Burgo, C.; Martín, E. L.; Snellen, I.; Barnes, J.; Campbell, D.; Catalan, S.; Gálvez-Ortiz, M. C.; Goulding, N.; Haswell, C.; Ivanyuk, O.; Jones, H.; Kuznetsov, M.; Lodieu, N.; Marocco, F.; Mislis, D.; Murgas, F.; Napiwotzki, R.; Palle, E.; Pollacco, D.; Sarro Baro, L.; Solano, E.; Steele, P.; Stoev, H.; Tata, R.; Zendejas, J.

2014-11-01

150

Tidal dissipation in planet-hosting stars: damping of spin-orbit misalignment and survival of hot Jupiters  

NASA Astrophysics Data System (ADS)

Observations of hot Jupiters around solar-type stars with very short orbital periods (˜1 d) suggest that tidal dissipation in such stars is not too efficient so that these planets can survive against rapid orbital decay. This is consistent with recent theoretical works, which indicate that the tidal quality factor, Q?, of planet-hosting stars can indeed be much larger than the values inferred from the circularization of stellar binaries. On the other hand, recent measurements of Rossiter-McLaughlin effects in transiting hot Jupiter systems not only reveal that many such systems have misaligned stellar spin with respect to the orbital angular momentum axis, but also show that systems with cooler host stars tend to have aligned spin and orbital axes. Winn et al. suggested that this obliquity-temperature correlation may be explained by efficient damping of stellar obliquity due to tidal dissipation in the convection zone of the star. This explanation, however, is in apparent contradiction with the survival of these short-period hot Jupiters. We show that in the solar-type parent stars of close-in exoplanetary systems, the effective tidal Q? governing the damping of stellar obliquity can be much smaller than that governing orbital decay. This is because, for misaligned systems, the tidal potential contains a Fourier component with frequency equal to the stellar spin frequency (in the rotating frame of the star) and rotating opposite to the stellar spin. This component can excite inertial waves in the convective envelope of the star, and the dissipation of inertial waves then leads to a spin-orbit alignment torque and a spin-down torque, but not orbital decay. By contrast, for aligned systems, such inertial wave excitation is forbidden since the tidal forcing frequency is much larger than the stellar spin frequency. We derive a general effective tidal evolution theory for misaligned binaries, taking account of different tidal responses and dissipation rates for different tidal forcing components.

Lai, Dong

2012-06-01

151

Conservation laws and mass distribution in the planet formation process  

Microsoft Academic Search

Within the framework of the nebular theory of the origin of the solar system, conservation laws are applied to the condensation of a ring shaped cloud of orbiting particles. The final configuration is assumed to be a point-like planet in a circular orbit around the Sun. On this ground, it is possible to relate the masses of the planets with

Paolo Farinella; Paolo Paolicchi

1977-01-01

152

An Understanding of the Shoulder of Giants: Jovian Planets around Late K Dwarf Stars and the Trend with Stellar Mass  

NASA Astrophysics Data System (ADS)

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 ? 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.

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

2013-07-01

153

4 The Search for Extrasolar Planets Only ten years ago, our knowledge of the existence of planets outside the solar  

E-print Network

of these planets, which orbit around main sequence stars, are of the Jupiter type and cannot be seats of life. In addition, four planets were discovered around pulsars, but here again the conditions for life hydrogen to burn (M is the mass of the Sun and MJ that of Jupiter). The surface temperature

Ulmschneider, Peter

154

Problem Set 1 (due 17th September) (1) A planet of radius Rp orbits a star of radius R in a circular orbit at radius a. If  

E-print Network

Problem Set 1 (due 17th September) (1) A planet of radius Rp orbits a star of radius R) Suppose that the planet, of mass Mp, orbital radius ap, and orbital period P, is itself orbited by a moon the presence of a moon similar to Jupiter's Ganymede orbiting a Jupiter mass planet at 0.1 AU about a Solar

Armitage, Phil

155

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

HOW DRY IS THE BROWN DWARF DESERT? QUANTIFYING THE RELATIVE NUMBER OF PLANETS, BROWN DWARFS of magnitude from brown dwarfs to Jupiter-mass planets. The slopes of the planetary and stellar companion mass Jupiter: 11% Ã? 3% are stellar, dwarf, and 5% Ã? 2% are giant planets. The steep decline

Lineweaver, Charles H.

156

Hot Jupiters and Cool Stars  

NASA Astrophysics Data System (ADS)

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 ?), 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.

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

2014-10-01

157

Two Jovian-Mass Planets in Earthlike Orbits  

E-print Network

We report the discovery of two new planets: a 1.94 M_Jup planet in a 1.8-year orbit of HD 5319, and a 2.51 M_Jup planet in a 1.1-year orbit of HD 75898. The measured eccentricities are 0.12 for HD 5319 b and 0.10 for HD 75898 b, and Markov Chain Monte Carlo simulations based on derived orbital parameters indicate that the radial velocities of both stars are consistent with circular planet orbits. With low eccentricity and 1 planets have orbits similar to terrestrial planets in the solar system. The radial velocity residuals of both stars have significant trends, likely arising from substellar or low-mass stellar companions.

Sarah E. Robinson; Gregory Laughlin; Steven S. Vogt; Debra A. Fischer; R. Paul Butler; Geoffrey W. Marcy; Gregory W. Henry; Peter Driscoll; Genya Takeda; John A. Johnson

2007-08-06

158

Detectability of Transiting Jupiters and Low-Mass Eclipsing Binaries in Sparsely Sampled Pan-STARRS-1 Survey Data  

NASA Astrophysics Data System (ADS)

We present detailed simulations of the Pan-STARRS-1 (PS1) multi-epoch, multiband 3? 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 3? Survey will be most sensitive to deep eclipses (gsim0.10 mag) caused by Jupiters transiting M dwarfs and eclipsing stellar/substellar binaries. The survey will measure parallaxes for the ~4 × 105 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 sstarf < 0.3 M sun) within 100 pc are potentially detectable in the PS1 3? Survey, along with ~300 low-mass eclipsing binaries (both component masses <0.5 M sun), including ~10 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.

Dupuy, Trent J.; Liu, Michael C.

2009-10-01

159

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

E-print Network

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.

Viki Joergens; Ralph Neuhäuser

2003-06-23

160

Testing the correlation between low mass planets and debris disks  

NASA Astrophysics Data System (ADS)

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.

Kalas, Paul

2014-10-01

161

Dunking the Planets  

NSDL National Science Digital Library

This is a demonstration about the density of the planets. Learners will compare the relative sizes and masses of scale models of the planets as represented by fruits and other foods. They will then dunk the "planets" in water to highlight the fact that even a large, massive planet - such as Saturn - can have low density. They discuss how a planet's density is related to whether it is mainly made up of rock or gas. This activity is part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

162

Lone Planet Under a Cosmic Magnifying Glass  

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...

163

The Ion Mass Imager on the Planet-B spacecraft  

Microsoft Academic Search

The Ion Mass Imager (IMI) is a light-weight ion mass composition instrument for the Japanese Planet-B mission to be launched to Mars in 1998. The objective of the Planet-B mission is to study the Martian environment with emphasis on the upper atmosphere interaction with the solar wind. IMI measures positive ions with energies between 10 eV\\/q and 35 keV\\/q and

O. Norberg; M. Yamauchi; R. Lundin; S. Olsen; H. Borg; S. Barabash; M. Hirahara; T. Mukai; H. Hayakawa

1998-01-01

164

Jupiter - friend or foe? III: the Oort cloud comets  

NASA Astrophysics Data System (ADS)

It has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of minor bodies on Earth. However, until recently, very little work had been carried out examining the role played by Jupiter in determining the frequency of such collisions. In this work, the third of a series of papers, we examine the degree to which the impact rate on Earth resulting from the Oort cloud comets is enhanced or lessened by the presence of a giant planet in a Jupiter-like orbit, in an attempt to more fully understand the impact regime under which life on Earth has developed. Our results show that the presence of a giant planet in a Jupiter-like orbit significantly alters the impact rate of Oort cloud comets on Earth, decreasing the rate as the mass of the giant planet increases. The greatest bombardment flux is observed when no giant planet is present.

Horner, J.; Jones, B. W.; Chambers, J.

2010-01-01

165

A new Neptune-mass planet orbiting HD 219828  

E-print Network

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.

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

2007-02-18

166

EXTRACTING PLANET MASS AND ECCENTRICITY FROM TTV DATA  

SciTech Connect

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.

Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA and Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) (United States); Xie Jiwei; Wu Yanqin [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

2012-12-20

167

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

168

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

SciTech Connect

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.

Dawson, Rebekah I.; Murray-Clay, Ruth A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, MS-10, Cambridge, MA 02138 (United States); Johnson, John Asher; Morton, Timothy D. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, California 95064 (United States); Howard, Andrew W., E-mail: rdawson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States)

2012-12-20

169

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)

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.

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

170

Mass release at Jupiter: Substorm-like processes in the Jovian magnetotail  

Microsoft Academic Search

The Jupiter orbiting spacecraft Galileo has provided evidence that the Jovian magnetotail is subject to a periodic process with typical timescales of several days by which the Jovian system is presumably releasing its excess iogenic mass. The mass release process resembles a terrestrial substorm in the sense of a global reconfiguration of the magnetotail. During the initial “loading” phase the

E. A. Kronberg; J. Woch; N. Krupp; A. Lagg; K. K. Khurana; K.-H. Glassmeier

2005-01-01

171

Dynamical corotation torques on low-mass planets  

NASA Astrophysics Data System (ADS)

We study torques on migrating low-mass planets in locally isothermal discs. Previous work on low-mass planets generally kept the planet on a fixed orbit, after which the torque on the planet was measured. In addition to these static torques, when the planet is allowed to migrate it experiences dynamical torques, which are proportional to the migration rate and whose sign depends on the background vortensity gradient. We show that in discs a few times more massive than the minimum-mass solar nebula, these dynamical torques can have a profound impact on planet migration. Inward migration can be slowed down significantly, and if static torques lead to outward migration, dynamical torques can take over, taking the planet beyond zero-torque lines set by saturation of the corotation torque in a runaway fashion. This means that the region in non-isothermal discs, where outward migration is possible, can be larger than what would be concluded from static torques alone.

Paardekooper, S.-J.

2014-11-01

172

The Obliquity of a Hot Jupiter in a Multi-Planet System  

NASA Astrophysics Data System (ADS)

We present the measured projected obliquity of a known transiting Jovian planet from the analysis of the Rossiter-McLaughlin (RM) effect in Keck-HIRES radial velocity data. We employ the new analytical approach of Hirano et al. (2011) that includes the effects of macroturbulence and instrumental broadening to accurately model the radial velocity shadow of a transiting planet, and foregoes the need to produce synthetic spectra on a case-by-case basis. RM measurements are an important tool for testing theories of planet formation and migration. To date, the measured obliquities of ~50 Jovian planets span the full range, from prograde to retrograde, with planets orbiting cool stars preferentially showing alignment of stellar spins and planetary orbits. Albrecht et al. (2012) interpret this pattern as the signature of tidal interactions with the convective envelopes of cool stars and close-in planets. This system is of particular interest because the tidal timescale for the transiting planet is relatively long and is thus a good test of the tidal-induced spin-orbit alignment theories.

Fulton, Benjamin; Howard, A.; Albrecht, S.; Johnson, J. A.; Knutson, H.; Marcy, G. W.; Winn, J. N.

2013-01-01

173

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

SciTech Connect

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.

Marley, Mark S. [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States); Saumon, Didier [Los Alamos National Laboratory, Mail Stop F663, Los Alamos, NM 87545 (United States); Cushing, Michael [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Ackerman, Andrew S. [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Freedman, Richard, E-mail: Mark.S.Marley@NASA.gov, E-mail: dsaumon@lanl.gov, E-mail: michael.cushing@utoledo.edu, E-mail: andrew.ackerman@nasa.gov, E-mail: jfortney@ucolick.org, E-mail: freedman@darkstar.arc.nasa.gov [SETI Institute and NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States)

2012-08-01

174

Why are there so few hot Jupiters?  

E-print Network

We use numerical simulations to model the migration of massive planets at small radii and compare the results with the known properties of 'hot Jupiters' (extrasolar planets with semi-major axes a 0.5 MJup, the evidence for any `pile-up' at small radii is weak (statistically insignificant), and although the mass function of hot Jupiters is deficient in high mass planets as compared to a reference sample located further out, the small sample size precludes definitive conclusions. We suggest that these properties are consistent with disc migration followed by entry into a magnetospheric cavity close to the star. Entry into the cavity results in a slowing of migration, accompanied by a growth in orbital eccentricity. For planet masses in excess of 1 Jupiter mass we find eccentricity growth timescales of a few x 10^5 years, suggesting that these planets may often be rapidly destroyed. Eccentricity growth appears to be faster for more massive planets which may explain changes in the planetary mass function at small radii and may also predict a pile-up of lower mass planets, the sample of which is still incomplete.

W. K. M. Rice; P. J. Armitage; D. F. Hogg

2007-12-05

175

Methane planets and the mass-radius diagram  

NASA Astrophysics Data System (ADS)

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.

Podolak, Morris; Helled, Ravit; Levi, Amit

2014-05-01

176

Search for earth mass planets and dark matter too  

SciTech Connect

Gravitational microlensing is known for baryonic dark matter searches. Here we show that microlensing also provides a unique tool for the detection of low mass planets (such as earths and neptunes) from the ground. A planetary system forms a binary lens (or, a multi-point lens), and we can determine the mass ratio of the planet with respect to the star and relative distance (= separation/Einstein ring radius) between the star and planet. Such a microlensing planet search project requires a {approx} 2 m survey telescope, and a network of 1.5 - 2 m follow-up telescopes capable of monitoring stars in the Bulge on a 24-hour basis. During the off-season of the Galactic bulge, this network can be used for dark matter search by monitoring the stars in the LMC and SMC.

Rhie, S.H.; Bennett, D.P. [Lawrence Livermore National Lab., CA (United States)][California Univ., Berkeley, CA (United States)][California Univ., Davis, CA (United States)][Notre Dame Univ., IN (United States)

1996-02-01

177

Orbital Evolution of Planets around Intermediate-Mass Giants  

Microsoft Academic Search

Around low- and intermediate-mass (1.5-3 Msolar) red giants, no planets have been found inside 0.6 AU. Such a paucity is not seen in the case of 1 Msolar main sequence stars. In this study, we examine the possibility that short-period planets were engulfed by their host star evolving off the main sequence. To do so, we have simulated the orbital

Masanobu Kunitomo; Masahiro Ikoma; Bun'ei Sato; Yutaka Katsuta; Shigeru Ida

2011-01-01

178

Orbital Evolution of Planets around Intermediate-Mass Giants  

Microsoft Academic Search

Around low- and intermediate-mass (1.5–3 M⊙) red giants, no planets have been found inside 0.6 AU. Such a paucity is not seen in the case of 1 M⊙ main sequence stars. In this study, we examine the possibility that short-period planets were engulfed by their host star evolving off the main sequence. To do so, we have simulated the orbital

Masanobu Kunitomo; Masahiro Ikoma; Bun’ei Sato; Yutaka Katsuta; Shigeru Ida

2011-01-01

179

Ab Initio Equation of State for Hydrogen-Helium Mixtures with Recalibration of the Giant-planet Mass-Radius Relation  

NASA Astrophysics Data System (ADS)

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, ~0.2-9 g cm-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 ~0.2 Jupiter radii at fixed entropy and for masses greater than ~0.5 Jupiter mass. This change is large enough to have possible implications for some discrepant "inflated giant exoplanets."

Militzer, B.; Hubbard, W. B.

2013-09-01

180

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

SciTech Connect

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''.

Militzer, B. [Departments of Earth and Planetary Science and of Astronomy, University of California, Berkeley, CA 94720 (United States); Hubbard, W. B. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2013-09-10

181

An extrasolar planetary system with three Neptune-mass planets  

E-print Network

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.

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

182

An extrasolar planetary system with three Neptune-mass planets.  

PubMed

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

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

183

Detectability of Habitable Planets around Very Low-Mass Stars  

NASA Astrophysics Data System (ADS)

We present observations of 18 very low-mass stars with Kepler light curves available in the public archive, where we performed a search for transits and characterized the photometric variability to estimate the effects of stellar activity in the detectability of habitable planets around stars at the cool end of the stellar mass distribution.

Martioli, E.; Martín, E. L.; Cabrera, J.; Solano, E.; Tata, R.

2014-10-01

184

Jupiter’s Great Red Spot and Ammonium Hydrosulfide  

NASA Astrophysics Data System (ADS)

The color and composition of Jupiter’s Great Red Spot (GRS) have been studied for over a century, and numerous explanations have been offered for this feature’s origin and properties. Since ammonium hydrosulfide (NH4SH) is thought to be a component of Jupiter’s clouds, and since sulfur chemistry is a rich source of colors, we have initiated a laboratory research program to study this ionic solid and a complementary program of GRS telescopic observations. Our initial experiments have investigated whether NH4SH or its radiation-chemical products might contribute to the spectrum of the GRS. This DPS presentation will cover some of our new results on the thermal and radiolytic stability of NH4SH, along with new infrared and mass spectral measurements. Support by NASA’s Planetary Atmospheres and Outer Planets Research programs is acknowledged.

Hudson, Reggie L.; Loeffler, Mark J.; Chanover , Nancy J.; Simon, Amy A.

2014-11-01

185

The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 day orbit around a late F-star [ERRATUM  

E-print Network

We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope (UKIRT) in August 2007. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J ~ 16 were constructed for ~60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01 +- 0.35 Mj and a planetary radius of 1.49+0.16-0.18 Rj. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Mj. The h...

Cappetta, M; Birkby, J L; Koppenhoefer, J; Pinfield, D J; Hodgkin, S T; Cruz, P; Kovacs, G; Sipocz, B; Barrado, D; Nefs, B; Pavlenko, Y V; Fossati, L; del Burgo, C; Martin, E L; Snellen, I; Barnes, J; Campbell, D A; Catalan, S; Galvez-Ortiz, M C; Goulding, N; Haswell, C; Ivanyuk, O; Jones, H; Kuznetsov, M; Lodieu, N; Marocco, F; Mislis, D; Murgas, F; Napiwotzki, R; Palle, E; Pollacco, D; Baro, L Sarro; Solano, E; Steele, P; Stoev, H; Tata, R; Zendejas, J

2014-01-01

186

The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 day orbit around a late F-star  

E-print Network

We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J=16 were constructed for 60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01+-0.35 Mj and a planetary radius of 1.49+-0.17 Rj. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Mj.

Cappetta, M; Birkby, J L; Koppenhoefer, J; Pinfield, D J; Hodgkin, S T; Cruz, P; Kovács, G; Sipöcz, B; Barrado, D; Nefs, B; Pavlenko, Y V; Fossati, L; del Burgo, C; Martín, E L; Snellen, I; Barnes, J; Bayo, A M; Campbell, D A; Catalan, S; Gálvez-Ortiz, M C; Goulding, N; Haswell, C; Ivanyuk, O; Jones, H; Kuznetsov, M; Lodieu, N; Marocco, F; Mislis, D; Murgas, F; Napiwotzki, R; Palle, E; Pollacco, D; Baro, L Sarro; Solano, E; Steele, P; Stoev, H; Tata, R; Zendejas, J

2012-01-01

187

PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS  

SciTech Connect

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.

Raymond, Sean N. [Center for Astrophysics and Space Astronomy, 389 UCB, University of Colorado, Boulder, CO 80309 (United States); Armitage, Philip J. [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Gorelick, Noel [Google, Inc., 1600 Amphitheatre Parkway, Mountain View, CA 94043 (United States)], E-mail: sean.raymond@colorado.edu

2009-07-10

188

Hot Jupiters and Cool Stars  

E-print Network

Close-in planets are in jeopardy as their host stars evolve off the main sequence to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5--2\\Mso ), 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 during 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 mass 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 ha...

Villaver, Eva; Mustill, Alexander J; Siess, Lionel

2014-01-01

189

The first planet detected in the WTS: an inflated hot Jupiter in a 3.35 d orbit around a late F star  

NASA Astrophysics Data System (ADS)

We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope (UKIRT) in 2007 August. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J ˜ 16 were constructed for ˜60 000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main-sequence dwarf (V = 16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 d, a planetary mass of 4.01 ± 0.35 MJ and a planetary radius of 1.49-0.18+0.16 RJ. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 MJ. The high irradiation from the host star ranks the planet in the pM class. Based on observations collected at the 3.8-m United Kingdom Infrared Telescope (Hawaii, USA), the Hobby-Eberly Telescope (Texas, USA), the 2.5-m Isaac Newton Telescope (La Palma, Spain), the William Herschel Telescope (La Palma, Spain), the German-Spanish Astronomical Centre (Calar Alto, Spain), the Kitt Peak National Observatory (Arizona, USA) and the Hertfordshire's Bayfordbury Observatory.

Cappetta, M.; Saglia, R. P.; Birkby, J. L.; Koppenhoefer, J.; Pinfield, D. J.; Hodgkin, S. T.; Cruz, P.; Kovács, G.; Sip?cz, B.; Barrado, D.; Nefs, B.; Pavlenko, Y. V.; Fossati, L.; del Burgo, C.; Martín, E. L.; Snellen, I.; Barnes, J.; Bayo, A.; Campbell, D. A.; Catalan, S.; Gálvez-Ortiz, M. C.; Goulding, N.; Haswell, C.; Ivanyuk, O.; Jones, H. R.; Kuznetsov, M.; Lodieu, N.; Marocco, F.; Mislis, D.; Murgas, F.; Napiwotzki, R.; Palle, E.; Pollacco, D.; Sarro Baro, L.; Solano, E.; Steele, P.; Stoev, H.; Tata, R.; Zendejas, J.

2012-12-01

190

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

Microsoft Academic Search

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

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

1998-01-01

191

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

Microsoft Academic Search

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

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

1998-01-01

192

INFLATING AND DEFLATING HOT JUPITERS: COUPLED TIDAL AND THERMAL EVOLUTION OF KNOWN TRANSITING PLANETS  

SciTech Connect

We examine the radius evolution of close in giant planets with a planet evolution model that couples the orbital-tidal and thermal evolution. For 45 transiting systems, we compute a large grid of cooling/contraction paths forward in time, starting from a large phase space of initial semimajor axes and eccentricities. Given observational constraints at the current time for a given planet (semimajor axis, eccentricity, and system age), we find possible evolutionary paths that match these constraints, and compare the calculated radii to observations. We find that tidal evolution has two effects. First, planets start their evolution at larger semimajor axis, allowing them to contract more efficiently at earlier times. Second, tidal heating can significantly inflate the radius when the orbit is being circularized, but this effect on the radius is short-lived thereafter. Often circularization of the orbit is proceeded by a long period while the semimajor axis slowly decreases. Some systems with previously unexplained large radii that we can reproduce with our coupled model are HAT-P-7, HAT-P-9, WASP-10, and XO-4. This increases the number of planets for which we can match the radius from 24 (of 45) to as many as 35 for our standard case, but for some of these systems we are required to be viewing them at a special time around the era of current radius inflation. This is a concern for the viability of tidal inflation as a general mechanism to explain most inflated radii. Also, large initial eccentricities would have to be common. We also investigate the evolution of models that have a floor on the eccentricity, as may be due to a perturber. In this scenario, we match the extremely large radius of WASP-12b. This work may cast some doubt on our ability to accurately determine the interior heavy element enrichment of normal, noninflated close in planets, because of our dearth of knowledge about these planets' previous orbital-tidal histories. Finally, we find that the end state of most close in planetary systems is disruption of the planet as it moves ever closer to its parent star.

Miller, N.; Fortney, J. J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Jackson, B. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)], E-mail: neil@astro.ucsc.edu, E-mail: jfortney@ucolick.org, E-mail: bjackson@lpl.arizona.edu

2009-09-10

193

Jupiter - friend or foe? III: the Oort cloud comets  

E-print Network

It has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of small bodies on the Earth. However, until recently, very little work had been carried out examining the role played by Jupiter in determining the frequency of such collisions. In this work, the third of a series of papers, we examine the degree to which the impact rate on Earth resulting from the Oort cloud comets is enhanced or lessened by the presence of a giant planet in a Jupiter-like orbit, in an attempt to more fully understand the impact regime under which life on Earth has developed. Our results show that the presence of a giant planet in a Jupiter-like orbit significantly alters the impact rate of Oort cloud comets on the Earth, decreasing the rate as the mass of the giant increases. The greatest bombardment flus is observed when no giant planet is present.

Horner, J; Chambers, J

2009-01-01

194

Planet formation around stars of various masses: Hot super-Earths  

E-print Network

We consider trends resulting from two formation mechanisms for short-period super-Earths: planet-planet scattering and migration. We model scenarios where these planets originate near the snow line in ``cold finger'' circumstellar disks. Low-mass planet-planet scattering excites planets to low periastron orbits only for lower mass stars. With long circularisation times, these planets reside on long-period eccentric orbits. Closer formation regions mean planets that reach short-period orbits by migration are most common around low-mass stars. Above ~1 Solar mass, planets massive enough to migrate to close-in orbits before the gas disk dissipates are above the critical mass for gas giant formation. Thus, there is an upper stellar mass limit for short-period super-Earths that form by migration. If disk masses are distributed as a power law, planet frequency increases with metallicity because most disks have low masses. For disk masses distributed around a relatively high mass, planet frequency decreases with increasing metallicity. As icy planets migrate, they shepherd interior objects toward the star, which grow to ~1 Earth mass. In contrast to icy migrators, surviving shepherded planets are rocky. Upon reaching short-period orbits, planets are subject to evaporation processes. The closest planets may be reduced to rocky or icy cores. Low-mass stars have lower EUV luminosities, so the level of evaporation decreases with decreasing stellar mass.

Grant M. Kennedy; Scott J. Kenyon

2008-04-15

195

[Extrasolar terrestrial planets and possibility of extraterrestrial life].  

PubMed

Recent development of research on extrasolar planets are reviewed. About 120 extrasolar Jupiter-mass planets have been discovered through the observation of Doppler shift in the light of their host stars that is caused by acceleration due to planet orbital motions. Although the extrasolar planets so far observed may be limited to gas giant planets and their orbits differ from those of giant planets in our Solar system (Jupiter and Saturn), the theoretically predicted probability of existence of extrasolar terrestrial planets that can have liquid water ocean on their surface is comparable to that of detectable gas giant planets. Based on the number of extrasolar gas giants detected so far, about 100 life-sustainable planets may exist within a range of 200 light years. Indirect observation of extrasolar terrestrial planets would be done with space telescopes within several years and direct one may be done within 20 years. The latter can detect biomarkers on these planets as well. PMID:15136756

Ida, Shigeru

2003-12-01

196

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

NASA Astrophysics Data System (ADS)

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.

Cohen, I. B.

1998-05-01

197

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

SciTech Connect

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).

Spiegel, David S.; Burrows, Adam [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Milsom, John A., E-mail: dsp@astro.princeton.edu, E-mail: burrows@astro.princeton.edu, E-mail: milsom@physics.arizona.edu [Department of Physics, University of Arizona, Tucson, AZ 85721 (United States)

2011-01-20

198

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

E-print Network

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.

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

2008-12-12

199

The HARPS search for southern extra-solar planets V. A 14 Earth-masses planet orbiting HD 4308  

E-print Network

We present here the discovery and characterisation of a very light planet around HD4308. The planet orbits its star in 15.56 days. The circular radial-velocity variation presents a tiny semi-amplitude of 4.1 m/s that corresponds to a planetary minimum mass m2sin(i)=14.1 Earth masses. The planet was unveiled by high-precision radial-velocity measurements obtained with the HARPS spectrograph on the ESO 3.6-m telescope. The radial-velocity residuals around the Keplerian solution are 1.3 m/s, demonstrating the very high quality of the HARPS measurements. Activity and bisector indicators exclude any significant perturbations of stellar intrinsic origin, which supports the planetary interpretation. Contrary to most planet-host stars, HD4308 has a marked sub-solar metallicity ([Fe/H]=-0.31), raising the possibility that very light planet occurrence might show a different coupling with the parent star's metallicity than do giant gaseous extra-solar planets. Together with Neptune-mass planets close to their parent stars, the new planet occupies a position in the mass-separation parameter space that is constraining for planet-formation and evolution theories. The question of whether they can be considered as residuals of evaporated gaseous giant planets, ice giants, or super-earth planets is discussed in the context of the latest core-accretion models.

S. Udry; M. Mayor; W. Benz; J. -L. Bertaux; F. Bouchy; C. Lovis; C. Mordasini; F. Pepe; D. Queloz; J. -P. Sivan

2005-10-12

200

Planet formation around stars of various masses: The snow line and the frequency of giant planets  

E-print Network

We use a semi-analytic circumstellar disk model that considers movement of the snow line through evolution of accretion and the central star to investigate how gas giant frequency changes with stellar mass. The snow line distance changes weakly with stellar mass; thus giant planets form over a wide range of spectral types. The probability that a given star has at least one gas giant increases linearly with stellar mass from 0.4 M_sun to 3 M_sun. Stars more massive than 3 M_sun evolve quickly to the main-sequence, which pushes the snow line to 10-15 AU before protoplanets form and limits the range of disk masses that form giant planet cores. If the frequency of gas giants around solar-mass stars is 6%, we predict occurrence rates of 1% for 0.4 M_sun stars and 10% for 1.5 M_sun stars. This result is largely insensitive to our assumed model parameters. Finally, the movement of the snow line as stars >2.5 M_sun move to the main-sequence may allow the ocean planets suggested by Leger et. al. to form without migration.

Grant M. Kennedy; Scott J. Kenyon

2007-10-04

201

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

SciTech Connect

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.

Fortney, Jonathan (University of California Santa Cruz) [University of California Santa Cruz

2011-06-11

202

MEASURE-Jupiter: Low-cost missions to explore Jupiter in the post-Galileo era  

Microsoft Academic Search

MEASURE-Jupiter is a mission concept for the first wave of new missions to explore the giant planets in the post-Galileo era. This paper addresses the feasibility of low-cost, focused science missions to explore Jupiter based on the science information returned by the Galileo mission. Delivery mass performance for spacecraft in the range of 100 to 200 kg is analyzed for

S. A. Stern; J. A. Ayon; C. L. Nunez; C. G. Sauer; D. S. Stetson; R. A. West

1995-01-01

203

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

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

204

The HARPS search for southern extra-solar planets. V. A 14 Earth-masses planet orbiting HD 4308  

Microsoft Academic Search

We present here the discovery and characterisation of a very light planet around HD 4308. The planet orbits its star in 15.56 days. The circular radial-velocity variation presents a tiny semi-amplitude of 4.1 m s-1 that corresponds to a planetary minimum mass m_2sin{i} = 14.1 Moplus (Earth masses). The planet was unveiled by high-precision radial-velocity measurements obtained with the HARPS

S. Udry; M. Mayor; W. Benz; J.-L. Bertaux; F. Bouchy; C. Lovis; C. Mordasini; F. Pepe; D. Queloz; J.-P. Sivan

2006-01-01

205

The orbital evolution of planets in disks  

E-print Network

The orbital parameters of the observed extrasolar planets differ strongly from those of our own solar system. The differences include planets with high masses, small semi-major axis and large eccentricities. We performed numerical computations of embedded planets in disks and follow their mass growth and orbital evolution over several thousand periods. We find that planets do migrate inwards on timescales of about $10^5$ years on nearly circular orbits, during which they may grow up to about 5 Jupiter masses. The interaction of the disk with several planets may halt the migration process and lead to a system similar to the solar planetary system.

Wilhelm Kley

2000-04-04

206

A stellar-mass-dependent drop in planet occurrence rates  

E-print Network

The Kepler Space Telescope has discovered a large number of planets up to one year periods and down to terrestrial sizes. The cool star subsample allows characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around sun-like stars. In this paper, we show that occurrence rates of planets around M, K, G, and F stars observed with Kepler are significantly different from each other. We identify two trends with stellar mass: First, the occurrence of Earth to Neptune-sized planets (1 to 4 Earth radii) is successively higher towards cooler stars at all orbital periods probed by Kepler, confirming the result of Howard et al. (2012) and extending it down to Earth-sized planets; Second, a drop in occurrence rates towards the star is evident for all spectral types inwards of a ~10 day orbital period, with a plateau further out. The distance from the star where this drop occurs depends on spectral type, and scales with semi-major axis as the cube root of...

Mulders, Gijs D; Apai, Daniel

2014-01-01

207

Estimating Masses and Orbits of Planets in Multiple-planet Systems with Joint Astrometry and RV Data Sets  

NASA Astrophysics Data System (ADS)

We describe a new algorithm for combining RV and astrometric observations of multiple-planet systems to obtain orbits and masses of individual planets. Because the algorithm uses only three nonlinear parameters per planet (instead of the usual five), its fast execution speed facilitates the application of MCMC methods to this problem. Multiple planet systems are relatively common; nearly 30 of about 200 known planetary systems discovered by RV have two or more planets, and many `single-planet’ systems show trends suggesting long period planets. RV observers routinely resolve multiple-planet systems, providing orbital solutions (but not masses or inclinations) for each planet. Though astrometry provides full orbital and mass solutions, the problem is more challenging; long-period orbits become confused with proper motion, and parallax can significantly attenuate the signal of a one-year planet. Combining longer-timespan RV data with astrometric data helps resolve multiple-planet systems by providing more information, as well as the capabilities to (1) access planets with periods between the timespans of the astrometric and RV observations, (2) determine orbit orientations in 3D, and (3) potentially eliminate `false alarm’ detections. In a recent double-blind test, we showed that combining simulated astrometric observations over 5 years (i.e., from the SIM-Lite mission) with ground-based RV observations covering 15 years provides the capability of detecting and characterizing Earthlike planets in multiple planet systems orbiting a solar-mass star at 10 pc. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

Catanzarite, Joseph; Zhai, C.; Shao, M.

2009-01-01

208

Properties of the short period CoRoT-planet population I: Theoretical planetary mass spectra for a population of stars of 0.8 to 2 solar masses and orbital periods of less then 20 days  

E-print Network

We study the planet populations in the discovery window of the CoRoT-space-telescope scheduled for launch on December 27th. We base the prediction on `first principles' calculations of planet formation in the framework of the planetesimal hypothesis. Aims: To provide a-priori planetary initial mass functions for confrontation with the CoRoT-planet discoveries in the entire range of sensitivity of the CoRoT instrument, i.e. for all giant planets and down to terrestrial planet masses. Methods: We construct a comprehensive set of static complete-equilibrium core-envelope protoplanets with detailed equations of state and opacity and radiative transfer by convection and radiation. Protoplanets are calculated for host-star masses of 0.8 to 2 solar masses and orbital periods of 1 to 16 days. We subsequently check the stability of the planetary population by a series of methods. Results: We find the static planetary populations to be stable and thus a plausible ensemble to predict the planetary IMF for orbital periods in the specified range. Conclusions: We predict bimodal planetary initial mass functions with shapes depending on orbital period. The two main maxima are around a Jupiter mass and about 50 earth masses. We predict an abundant population of Hot Neptunes and a large population of planets that fill the solar-system gap of planetary masses between Neptune and Saturn.

G. Wuchterl; C. Broeg; S. Krause; B. Pecnik; J. Schoenke

2006-12-29

209

Constraining Planetary Migration Mechanisms with Highly Eccentric Hot Jupiter Progenitors  

NASA Astrophysics Data System (ADS)

Abstract: Hot Jupiters --- Jupiter-mass planets orbiting within 0.1 AU of their host stars --- are unlikely to have formed in situ and thus serve as evidence for the prevalence of planetary migration. However, it is debated whether the typical hot Jupiter migrated smoothly inward through the protoplanetary disk or was perturbed onto an eccentric orbit, which tidal dissipation subsequently shrank and circularized during close passages to the star. In the latter class of model, the perturber may be a stellar or planetary companion, which causes the Jupiter to undergo a temporary epoch with high eccentricity (e> 0.9). Socrates and et al. (2012) predicted that these super-eccentric hot Jupiter progenitors should be readily discoverable through the transit method by the Kepler Mission. However, eccentricities of individual transiting planets primarily come from Doppler measurements, which are unfortunately precluded by the faintness of most Kepler targets. To solve this problem, we developed a Bayesian method (the “photoeccentric effect”) for measuring an individual planet's eccentricity solely from its Kepler light curve, allowing for a tight measurement of large eccentricities. We applied this new approach to the Kepler giant planet candidates and identified KOI-1474.01 as an eccentric planet (e = 0.81+0.10/-0.07) with an average orbital period of 69.7340 days, varying by approximately 1 hour due to perturbations by a massive outer companion, which is possibly the culprit responsible for KOI-1474.01’s highly eccentric orbit. KOI-1474.01 is likely a failed hot Jupiter, too far from its host star to be tidally transformed into a hot Jupiter. We found a significant lack of super-eccentric proto-hot Jupiters compared to the number expected, allowing us to place a strong upper limit on the fraction of hot Jupiters created by stellar binaries. Our results are consistent with disks or planetary companions being the primary channel for hot Jupiter creation. Supported by NSFGRFP DGE-1144152.

Dawson, Rebekah I.; Johnson, J. A.; Murray-Clay, R.; Morton, T.; Crepp, J. R.; Fabrycky, D. C.; Howard, A.

2013-01-01

210

Orbital Circularization of a Planet Accreting Disk Gas: Formation of Distant Jupiters in Circular Orbits based on Core Accretion Model  

E-print Network

Recently, gas giant planets in nearly circular orbits with large semimajor axes ($a \\sim$ 30--1000AU) have been detected by direct imaging. We have investigated orbital evolution in a formation scenario for such planets, based on core accretion model: i) Icy cores accrete from planetesimals at $\\lesssim$ 30AU, ii) they are scattered outward by an emerging nearby gas giant to acquire highly eccentric orbits, and iii) their orbits are circularized through accretion of disk gas in outer regions, where they spend most of time. We analytically derived equations to describe the orbital circularization through the gas accretion. Numerical integrations of these equations show that the eccentricity decreases by a factor of more than 5 during the planetary mass increases by a factor of 10. Because runaway gas accretion increases planetary mass by $\\sim$ 10--300, the orbits are sufficiently circularized. On the other hand, $a$ is reduced at most only by a factor of 2, leaving the planets in outer regions. If the relativ...

Kikuchi, A; Ida, S

2014-01-01

211

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

E-print Network

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 larger masses (though there is a wide range between Jupiter at the massive end and Uranus / Neptune

Armitage, Phil

212

A closely packed system of low-mass, low-density planets transiting Kepler11  

Microsoft Academic Search

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

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

2011-01-01

213

The Galileo Probe Mass Spectrometer: Composition of Jupiter's Atmosphere  

Microsoft Academic Search

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 H_2 (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

Hasso B. Niemann; Sushil K. Atreya; George R. Carignan; Thomas M. Donahue; John A. Haberman; Dan N. Harpold; Richard E. Hartle; Donald M. Hunten; Wayne T. Kasprzak; Paul R. Mahaffy; Tobias C. Owen; Nelson W. Spencer

1996-01-01

214

Planet Traps and First Planets: The Critical Metallicity for Gas Giant Formation  

NASA Astrophysics Data System (ADS)

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 (\\mathinner {\\langle {R_{rapid}}\\rangle }) 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 \\mathinner {\\langle {R_{rapid}}\\rangle } 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.

Hasegawa, Yasuhiro; Hirashita, Hiroyuki

2014-06-01

215

Early planet formation as a trigger for further planet formation  

E-print Network

Recent discoveries of extrasolar planets at small orbital radii, or with significant eccentricities, indicate that interactions between massive planets and the disks of gas and dust from which they formed are vital for determining the final shape of planetary systems. We show that if this interaction occurs at an early epoch, when the protoplanetary disc was still massive, then rapid planet growth through accretion causes an otherwise stable disc to fragment into additional planetary mass bodies when the planetary mass reaches 4-5 Jupiter masses. We suggest that such catastrophic planet formation could account for apparent differences in the mass function of massive planets and brown dwarfs, and the existence of young stars that appear to have dissipated their discs at an early epoch. Subsequent gravitational interactions will lead to planetary systems comprising a small number of massive planets in eccentric orbits.

Philip J. Armitage; Brad M. S. Hansen

1999-12-08

216

The Trojan minor planets  

Microsoft Academic Search

There are (March, 1988) 3774 minor planets which have received a permanent number. Of these, there are some whose mean distance to the sun is very nearly equal to that of Jupiter, and whose heliocentric longitudes from that planet are about 60°, so that the three bodies concerned (sun, Jupiter, minor planet) make an approximate equilateral triangle. These minor planets,

Christopher E. Spratt

1988-01-01

217

8The Cometary Planet: HD 209458b Every 4 days, this planet orbits  

E-print Network

8The Cometary Planet: HD 209458b Every 4 days, this planet orbits a sun-like star located 153 light of atmosphere loss may be as high as 4x10 11 grams/sec. How fast is it losing mass in: A) metric tons per day? B) metric tons per year? Problem 2 - The mass of the planet is about 60% of Jupiter, and its radius is about

218

Gravitational energy sources in Jupiter  

NASA Technical Reports Server (NTRS)

Gravitational sources of the intrinsic luminosity of Jupiter are examined in the context of current hydrogen-helium models. When no gravitational separation of matter occurs, the amount of heat which can be released over the remaining lifetime of the planet is necessarily limited by the size of its existing reservoir of thermal energy. This conclusion rests only on the assumption that its interior is relatively cold and degenerate. If gravitational unmixing occurs, the size of the thermal reservoir does not necessarily limit the heat output. If core formation occurs, for example, then the size of the core formed will be a limiting factor. The energy released with the formation of a helium core is computed for Jupiter. A core growth rate, averaged over several billion years, of 20 trillionths of Jupiter's mass per year is required if gravitational separation is to play a significant role in the thermal evolution.

Flasar, F. M.

1973-01-01

219

Moons around Jupiter  

NASA Technical Reports Server (NTRS)

The New Horizons Long Range Reconnaissance Imager (LORRI) took this photo of Jupiter at 20:42:01 UTC on January 9, 2007, when the spacecraft was 80 million kilometers (49.6 million miles) from the giant planet. The volcanic moon Io is to the left of the planet; the shadow of the icy moon Ganymede moves across Jupiter's northern hemisphere.

Ganymede's average orbit distance from Jupiter is about 1 million kilometers (620,000 miles); Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon; Ganymede is larger than the planet Mercury.

2007-01-01

220

Mars and Jupiter  

NSDL National Science Digital Library

Students explore Mars and Jupiter, the fourth and fifth planets from the Sun. They learn some of the unique characteristics of these planets. They also learn how engineers help us learn about these planets with the design and development of telescopes, deep space antennas, spacecraft and planetary rovers.

Integrated Teaching And Learning Program

221

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

PubMed

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. PMID:8629016

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

1996-05-10

222

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

NASA Technical Reports Server (NTRS)

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.

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

223

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

SciTech Connect

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.

Poppenhaeger, K.; Schmitt, J. H. M. M., E-mail: katja.poppenhaeger@hs.uni-hamburg.de [Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg (Germany)

2011-07-01

224

Planets  

NSDL National Science Digital Library

Pick a planet and tell me 6 different facts you learned about that planet. First to help you remember your planets and which order they go in watch this video Afer the video you may take a few minutes and choose which game to play. Now go through these pictures and see how neat the planets look from space. Now click hereand here and research which planet you would ...

2012-04-11

225

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

Microsoft Academic Search

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

William B. Hubbard

2005-01-01

226

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

SciTech Connect

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.

Wittenmyer, Robert A.; Horner, J.; Salter, G. S.; Tinney, C. G.; Bailey, J. [Department of Astrophysics, School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Tuomi, Mikko; Zhang, Z. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Butler, R. P. [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States); Jones, H. R. A. [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, AL10 9AB (United Kingdom); O'Toole, S. J. [Australian Astronomical Observatory, P.O. Box 296, Epping, NSW 1710 (Australia); Carter, B. D. [Faculty of Sciences, University of Southern Queensland, Toowoomba, Queensland 4350 (Australia); Jenkins, J. S. [Departamento de Astronomia, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile); Vogt, S. S.; Rivera, Eugenio J., E-mail: rob@phys.unsw.edu.au [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)

2012-07-10

227

SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS  

SciTech Connect

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.

Wu Yanqin [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON (Canada); Lithwick, Yoram [Canadian Institute of Theoretical Astrophysics, Toronto, ON (Canada)

2011-07-10

228

The Jupiter Twin HD 154345b  

E-print Network

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.

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

2008-02-12

229

Toward Chemical Constraints on Hot Jupiter Migration  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

230

The Pull of the Planets  

NSDL National Science Digital Library

In this activity, learners model the gravitational fields of planets on a flexible surface. Learners place and move balls of different sizes and densities on a plastic sheet to develop a mental picture of how the mass of an object influences how much effect it has on the surrounding space. This activity is part of a sequence of activities focused on Jupiter's immense size.

Institute, Lunar A.; Nasa

2011-01-01

231

Formation of the Giant Planets  

Microsoft Academic Search

The structure of a gaseous envelope surrounding a protoplanet has been investigated in connection with the formation of the giant planets. Under the assumptions of spherical symmetry and hydrostatic equilibrium, the structure has been calculated for the regions of Jupiter, Saturn, Uranus and Neptune. Energy transfer in the envelope has been taken into account precisely. When the core mass increases

Hiroshi Mizuno

1980-01-01

232

Juno: Launching to Jupiter  

NASA Video Gallery

The Juno spacecraft will look deep beneath Jupiter's swirling curtains of clouds to decipher the planet's structure and history during a mission that will begin with a 5-year flight through deep sp...

233

Abundances of Elements in Jupiter’s Atmosphere  

NASA Astrophysics Data System (ADS)

As measured by the Galileo mission, Jupiter’s atmosphere is enriched (relative to H and a protosolar composition) in Ar, Kr, Xe, C, N, S and P, by a similar factor of 3 [1]; it is depleted in He, Ne and O. Fractionation of Ar from H requires temperatures < 35 K [2], but multiple theories exist invoking trapping of species in ices, in principle explaining these enrichments [3-5]. He is depleted by 18%, and Ne by 88% [1]. At the ~1 Mbar level in Jupiter’s atmosphere, where H transitions to a metallic state, He droplets can form that precipitate to Jupiter’s core; Ne, but not Ar, is expected to dissolve into these droplets, explaining the depletion of both He and Ne [6]. The factor-of-2 depletion of O is currently unexplained but is attributed to meteorological effects [7]. The Juno mission en route to Jupiter will measure the global abundance of O [8].We present a model for the enrichments of Ar, Kr, Xe, C, N, S and P. Our model [8] builds on that of [5] in which Jupiter accretes nebular gas depleted in H by photoevaporation. Our model improvements allow enrichments with less mass loss, and explain how water vapor can be produced at T < 35 K, necessary for trapping of Ar and other species. We predict that Jupiter accreted with a factor-of-3 enrichment of O, but was then sequestered into Jupiter’s core along with He and Ne, potentially explaining its factor-of-2 depletion.References:[1] Desch, SJ, Shumway, J, & Monga, N, submitted to Icarus.[2] Bar-Nun, A, Herman, G, Laufer, D, & Rappaport, ML 1985. Icarus 63, 317.[3] Owen, T, et al.1999, Nature 402, 269. [4] Gautier, D, Hersant, F, Mousis, O, & Lunine, JI 2001, Ap.J. 550, L227.[5] Guillot, T & Hueso, R 2006, Mon. Not. Roy. Astron. Soc. 367, L47.[6] Wilson, HF & Militzer, B 2010, Phys Rev Lett.104, 121101.[7] Atreya, SK et al. 1999, Planet. Space Sci. 47, 1243.[7] Janssen, MA et al. 2005, Icarus 173, 447. [8] Monga, N & Desch, SJ, submitted to Ap.J.

Desch, Steven; Monga, Nikhil

2014-11-01

234

Planets  

NSDL National Science Digital Library

What planets are in our solar system? Today, we are going to learn about the eight planets in our solar system. While learning, we're going to try to answer the question: What planets are in our solar system? Use this Planet Organizer to fill in information about the solar system that you learn on your journey! First, we're going to find ...

Anderson, Ms.

2011-04-07

235

Planets  

NSDL National Science Digital Library

This radio broadcast discusses developments in the search for extraterrestrial planets. Topics include what causes a planet to form, and how they are detected. There is also speculation on the liklihood of an Earth-like planet being found and the basic requirements for extraterrestrial life. The broadcast is 42 minutes in length.

236

Discovery of a Jupiter/Saturn analog with gravitational microlensing.  

PubMed

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

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

237

Noble gas abundance and isotope ratios in the atmosphere of Jupiter from the Galileo Probe Mass Spectrometer  

Microsoft Academic Search

The Galileo Probe Mass Spectrometer provided the first data on the noble gas mixing and isotope ratios in the Jovian atmosphere. These measurements and the comparison with solar values constrain models of Jupiter's formation. Significant refinements to the initially reported abundances of argon, krypton, and xenon have been enabled through post-encounter laboratory calibrations using a refurbished engineering unit mass spectrometer

P. R. Mahaffy; H. B. Niemann; A. Alpert; S. K. Atreya; J. Demick; T. M. Donahue; D. N. Harpold; T. C. Owen

2000-01-01

238

Small, numerous and close-in: How occurrence rates of planets around lower-mass stars can constrain planet formation mechanisms.  

NASA Astrophysics Data System (ADS)

The Kepler Space Telescope has observed stars from spectral type M to F, and differences in the distribution of planets between these types hold vital clues for unraveling the planet formation process. We present planet occurrence rates as a function of spectral type for planets of different sizes and orbital periods. We find that the distributions are significantly different: Occurrence rates increase towards lower-mass stars, the planet population is truncated at different distances form the star for different spectral types, and planets around smaller stars are systematically smaller. These trends with stellar mass are linked to protoplanetary disk properties: The planet truncation radius matches the gas disk co-rotation radius, while smaller planets form in less massive disks around lower-mass stars. These results favor a hybrid formation and migration scenario where planetary building blocks migrate towards the disk inner edge and form planets that still reflect the initial disk mass.

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

2014-11-01

239

On the Track of Very Low-mass Planets with HARPS  

Microsoft Academic Search

In only one and a half years of operation HARPS has discovered eight new extra-solar planet candidates. Many more discoveries are expected with the increase of the duration of the survey. What makes HARPS unique compared with other instruments is its unprecedented precision and its ability to discover planets with very low mass. In fact, all the planets discovered with

Francesco Pepe; Michel Mayor; Didier Queloz; Willy Benz; Jean-Loup Bertaux; Francois Bouchy; Christophe Lovis; Christoph Mordasini; Nuno Santos; Jean-Pierre Sivan; Stephane Udry

2005-01-01

240

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

E-print Network

mass function of the brown dwarfs/giant planets, we need to conduct more compre- hensive surveys in this paper and the close (0.5 to 10 astronomical units) extrasolar giant planets and brown dwarfs around. Bodenheimer {in Extrasolar Planets and Brown Dwarfs, R. Rebolo et al., Eds. [Astronomical Society

Zreda, Marek

241

Extrasolar Binary Planets. I. Formation by Tidal Capture during Planet-Planet Scattering  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

242

Inversion of Jupiter and Satrun gravity field into the atmospheric circulation on these planets - using the gravity measurements by Juno and Cassini and an adjoint based dynamical model  

NASA Astrophysics Data System (ADS)

In approximately two years Juno and Cassini will both perform close flybys of Jupiter and Saturn respectively, obtaining a high precision gravity spectrum for these planets. This data can be used to estimate the depth of the observed flows on these planets. Here we use a hierarchy of dynamical models in order to relate the three dimensional flow to perturbations of the density field, and therefore to the gravity field. The models are set up to allow either zonal flow only, or a full horizontal flow in both zonal and meridional directions based on the observed cloud-level winds. In addition, dynamical perturbations resulting from the non-spherical shape of the planets are accounted for. In order to invert the gravity field to be measured by Juno and Cassini into the 3D circulation, an adjoint inverse model is constructed for the dynamical model, thus allowing backward integration of the dynamical model. This tool can be used for examination of various scenarios, including cases in which the depth of the winds depends on latitudinal position.We show that given the expected sensitivities of Juno and Cassini, it is possible to use the gravity measurements to derive the depth of the winds, both on Jupiter and Saturn. This holds for a large range of zonal wind possible penetration depths, from ~100km to ~10000km, and for winds depth that vary with latitude. This method proves to be useful also when incorporating the full horizontal flow, and thus taking into account gravity perturbations that vary with longitude. We show that our adjoint based inversion method allows not only to estimate the depth of the circulation, but allows via iterations with the spacecraft trajectory estimation model to improve the inferred gravity field.

Galanti, Eli; Kaspi, Yohai

2014-11-01

243

Jupiter: friend or foe?  

NASA Astrophysics Data System (ADS)

The idea that Jupiter has shielded the Earth from potentially catastrophic impacts has long permeated the public and scientific mind. But has it shielded us? We are carrying out the first detailed examination of the degree of shielding provided by Jupiter and have obtained some surprising results. Rather than Jupiter acting as a defensive presence, we found that it actually makes little difference - but if Jupiter were significantly smaller, the impact rate experienced by the Earth would be considerably enhanced. Indeed, it seems that a giant planet in the outer reaches of a planetary system can actually pose a threat to the habitability of terrestrial worlds closer to the system's parent star.

Horner, Jonti; Jones, Barrie W.

2008-02-01

244

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

SciTech Connect

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.

Guo, J. H. [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)

2010-04-01

245

Planets  

NSDL National Science Digital Library

The purpose of this project is to gather information and learn interesting facts about the planets in our solar sytem to complete a research project for Mrs. Hutchinson\\'s class. Begin by taking a quiz to measure your knowledge. Click this link for information and quiz. Quiz Next, you will choose two of the following sites and search for information on the planets in our solar system. Fill in the questions on your work sheet as you go to each site. Factmonster Planets Kids Astronomy 9 planets for kids Windows to the Universe Just for ...

Bhanks

2006-11-02

246

Quantifying Jupiter's influence on the Earth's impact flux: Implications for planetary habitability  

E-print Network

It has long been thought that the presence of a giant planet is a pre-requisite for the development of life on potentially habitable planets. Without Jupiter, it was argued, the Earth would have been subject to a punishing impact regime, which would have significantly retarded or outright prevented the development of life on our planet. Although this idea is widely embraced, little research has previously been carried out to support it. Here, we present the results of several suites of dynamical integrations used to model the influence of Jupiter's mass and orbit on the impact rate that would be experienced by the Earth. We find that, far from being a simple shield, Jupiter's role in determining the terrestrial impact flux is significantly more complicated than previously thought. Far from being a simple friend, such giant planets are perhaps more likely to imperil the development of life on otherwise habitable planets.

Horner, J

2012-01-01

247

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

SciTech Connect

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.

Ghezzi, L.; Cunha, K.; De Araujo, F. X.; De la Reza, R. [Observatorio Nacional, Rua General Jose Cristino, 77, 20921-400, Sao Cristovao, Rio de Janeiro, RJ (Brazil); Smith, V. V.; Schuler, S. C., E-mail: luan@on.b [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

2010-09-10

248

Deuterium Burning in Massive Giant Planets and Low-mass Brown Dwarfs Formed by Core-nucleated Accretion  

NASA Astrophysics Data System (ADS)

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 ?, are assumed to accrete gas up to final masses of 10-15 Jupiter masses (M 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 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 50 fall in the range 11.6-13.6 M 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 50. For masses above M 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.

Bodenheimer, Peter; D'Angelo, Gennaro; Lissauer, Jack J.; Fortney, Jonathan J.; Saumon, Didier

2013-06-01

249

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

SciTech Connect

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.

Bodenheimer, Peter [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); D'Angelo, Gennaro; Lissauer, Jack J. [Space Science and Astrobiology Division, NASA-Ames Research Center, Moffett Field, CA 94035 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Saumon, Didier, E-mail: peter@ucolick.org, E-mail: gennaro.dangelo@nasa.gov, E-mail: Jack.J.Lissauer@nasa.gov, E-mail: jfortney@ucolick.org, E-mail: dsaumon@lanl.gov [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2013-06-20

250

The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets  

Microsoft Academic Search

We report on the results of an 8-year survey carried out at the La Silla Observatory with the HARPS spectrograph to detect and characterize planets in the super-Earth and Neptune mass regime. The size of our star sample and the precision achieved with HARPS have allowed the detection of a sufficiently large number of low-mass planets to study the statistical

M. Mayor; M. Marmier; C. Lovis; S. Udry; D. Ségransan; F. Pepe; W. Benz; J.-L. Bertaux; F. Bouchy; X. Dumusque; G. Lo Curto; C. Mordasini; D. Queloz; N. C. Santos

2011-01-01

251

Unambiguous black hole mass from polarimetry and application to hot Jupiters  

NASA Astrophysics Data System (ADS)

A novel technique for detecting light scattered by extrasolar planets is presented that has the potential to constrain orbital inclination and planet mass. To develop this technique, I have commissioned a high precision polarimeter on the Hale 5-m telescope at Palomar Observatory. The high mass X-ray binary Cygnus X-1 has been observed, which is a proxy for extrasolar planet studies. The single scattering model of Brown et al. (1978), widely used in the literature, predicts an orbital inclination for Cygnus X-1 that is inconsistent with the lack of observed X-ray eclipses to 4 - 5. Previous studies have hinted at this discrepancy, but data quality was such that the confidence in such a discrepancy was not statistically significant. My observations represent the highest precision study of this object, and they illustrate the overwhelming complexity of the supergiant/black hole system. They also call into question the validity of the Brown et al. (1978) formalism, widely used by the community, for inclination estimation in binary systems. Extrasolar planet host stars have also been observed, and precision of order one part per million has been achieved on bright targets. Precision attained on fainter host stars is of order one part in 10^5 . While scattered light from extrasolar planets has not been conclusively detected, a planetary transit in the HD 189733 system may have been observed in polarized light. Such an event is observed to be 1,000 times weaker in polarized light than in photometry, and it indicates a planetary transit of the Southern Hemisphere of the host star. Such geometric information is difficult to determine by other methods. The integrated polarization of the debris disk surrounding ? Ophiuchi has been observed to high precision, and the position angle of net polarization is aligned with the disk major axis as seen by the Spitzer Space Telescope. This indicates the disk is primarily composed of forward scattering dust grains larger than the wavelengths of visible light. Finally, Neptune-mass extrasolar planets orbiting close to their host stars have been modeled to be far too warm for liquid water oceans to exist in their upper atmospheres.

Wiktorowicz, Sloane John

252

A search for multi-planet systems  

NASA Astrophysics Data System (ADS)

I report the results of a three-year intensive radial-velocity survey of 22 planet-host stars in search of the low-amplitude ( K ~5-10 m s -1 ) signals from additional planets which may be "hiding" in the residuals of the known planet orbital solution. On average, more than 40 radial-velocity observations were obtained for each target using the High-Resolution Spectrograph at the 9.2m Hobby-Eberly Telescope (HET). These high-precision data can be used to rule out additional planets in some of these systems to a detection limit of M sin i ~10-20 Earth masses at a = 0.05 AU. Jupiter-mass planets can be excluded at the 99% level for orbital separations a < 2 AU. No additional planets are evident, and our data do not confirm the planets HD 20367b, HD 74156d, and 47 UMa c. Test particle simulations of these systems with the SWIFT N-body integrator reveal the regions where additional planets could reside in stable orbits. Further simulations with Saturn-mass bodies in these regions are also performed. We note a lack of short-period giant planets in any of these 22 systems, despite dynamical feasibility. The frequency of inner giant planets may be much lower than what was expected based on early discoveries of such objects in systems containing jovian-mass planets. Terrestrial-mass planets may be present in these systems but as yet undetectable. These results suggest that planet formation and migration processes do not favor systems containing both "hot" and "cold" Jupiters. Hence, as detection methods become sensitive to terrestrial-mass planets, systems with architectures like our own Solar system may yet be commonplace.

Wittenmyer, Robert Andrew

253

Transiting exoplanets from the CoRoT space mission . XIII. CoRoT-13b: a dense hot Jupiter in transit around a star with solar metallicity and super-solar lithium content  

Microsoft Academic Search

We announce the discovery of the transiting planet CoRoT-13b. Ground-based follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the planet was measured with the HARPS spectrograph and the properties of the host star were obtained analyzing HIRES spectra from the Keck telescope. It is a hot Jupiter-like planet with an orbital period of 4.04 days, 1.3 Jupiter

Juan Cabrera; Hans Bruntt; M. Ollivier; R. F. Díaz; Szilard Csizmadia; Suzanne Aigrain; Roi Alonso; J.-M. Almenara; Michel Auvergne; Annie Baglin; P. Barge; A. S. Bonomo; P. Bordé; F. Bouchy; L. Carone; S. Carpano; M. Deleuil; H. J. Deeg; R. Dvorak; A. Erikson; S. Ferraz-Mello; M. Fridlund; D. Gandolfi; J.-C. Gazzano; M. Gillon; E. W. Guenther; T. Guillot; A. Hatzes; M. Havel; G. Hébrard; L. Jorda; A. Léger; A. Llebaria; H. Lammer; C. Lovis; T. Mazeh; C. Moutou; A. Ofir; P. von Paris; M. Pätzold; D. Queloz; H. Rauer; D. Rouan; A. Santerne; J. Schneider; B. Tingley; R. Titz-Weider; G. Wuchterl

2010-01-01

254

CAPTURE OF TROJANS BY JUMPING JUPITER  

SciTech Connect

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.

Nesvorny, David [Department of Space Studies, Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States); Vokrouhlicky, David [Institute of Astronomy, Charles University, V Holesovickach 2, 180 00 Prague 8 (Czech Republic); Morbidelli, Alessandro [Departement Cassiopee, University of Nice, CNRS, Observatoire de la Cote d'Azur, Nice, F-06304 (France)

2013-05-01

255

Capture of Trojans by Jumping Jupiter  

NASA Astrophysics Data System (ADS)

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 ~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) × 10-7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 107 planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M disk ~ 14-28 M Earth, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

Nesvorný, David; Vokrouhlický, David; Morbidelli, Alessandro

2013-05-01

256

CAPTURE OF TROJANS BY JUMPING JUPITER  

NASA Astrophysics Data System (ADS)

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 (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 ~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) × 10^-7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 10^7 planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M_disk ~ 14-28 M_Earth, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

Nesvorny, David; Vokrouhlicky, D.; Morbidelli, A.

2013-10-01

257

X-MIME: An Imaging X-ray Spectrometer for Detailed Study of Jupiter's Icy Moons and the Planet's X-ray Aurora  

NASA Technical Reports Server (NTRS)

Remote observations with the Chandra X-ray Observatory and the XMM-Newton Observatory have shown that the Jovian system is a source of x-rays with a rich and complicated structure. The planet's polar auroral zones and its disk are powerful sources of x-ray emission. Chandra observations revealed x-ray emission from the Io Plasma Torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from these moons is certainly due to bombardment of their surfaces of highly energetic protons, oxygen and sulfur ions from the region near the Torus exciting atoms in their surfaces and leading to fluorescent x-ray emission lines. Although the x-ray emission from the Galilean moons is faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around these moons, operating at 200 eV and above with 150 eV energy resolution, would provide a detailed mapping (down to 40 m spatial resolution) of the elemental composition in their surfaces. Such maps would provide important constraints on formation and evolution scenarios for the surfaces of these moons. Here we describe the characteristics of X-MIME, an imaging x-ray spectrometer under going a feasibility study for the JIMO mission, with the ultimate goal of providing unprecedented x-ray studies of the elemental composition of the surfaces of Jupiter's icy moons and Io, as well as of Jupiter's auroral x-ray emission.

Elsner, R. F.; Ramsey, B. D.; Waite, J. H.; Rehak, P.; Johnson, R. E.; Cooper, J. F.; Swartz, D. A.

2004-01-01

258

Towards Chemical Constraints on Hot Jupiter Migration  

E-print Network

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 expla...

Madhusudhan, Nikku; Kennedy, Grant M

2014-01-01

259

Planet-Planet Scattering in Planetesimal Disks. II. Predictions for Outer Extrasolar Planetary Systems  

NASA Astrophysics Data System (ADS)

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 ? from 10 to 20 AU. For large planet masses (M >~ M 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 <~ 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 ? 5 m s-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 ~ 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.

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

2010-03-01

260

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

SciTech Connect

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.

Raymond, Sean N. [Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, 2 rue de l'Observatoire, BP 89, F-33271 Floirac Cedex (France); Armitage, Philip J. [JILA, University of Colorado, Boulder, CO 80309 (United States); Gorelick, Noel, E-mail: pja@jilau1.colorado.ed [Google, Inc., 1600 Amphitheatre Parkway, Mountain View, CA 94043 (United States)

2010-03-10

261

Planet Consumption and Stellar Metallicity Enhancements  

NASA Astrophysics Data System (ADS)

The evolution of a giant planet within the stellar envelope of a main-sequence star is investigated as a possible mechanism for enhancing the stellar metallicities of the parent stars of extrasolar planetary systems. Three-dimensional hydrodynamical simulations of a planet subject to impacting stellar matter indicate that the envelope of a Jupiter-like giant planet can be completely stripped in the outer stellar convection zone of a 1 Msolar star. In contrast, Jupiter-like and less massive Saturn-like giant planets are able to survive through the base of the convection zone of a 1.22 Msolar star. Although strongly dependent on details of planetary interior models, partial or total dissolution of giant planets can result in significant enhancements in the metallicity of host stars with masses in the range 1.0 Msolar<~M<~1.3 Msolar. The implications of these results with regard to planetary orbital migration are briefly discussed.

Sandquist, Eric; Taam, Ronald E.; Lin, D. N. C.; Burkert, Andreas

1998-10-01

262

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

NASA Astrophysics Data System (ADS)

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.

Hatzes, A. P.

2014-08-01

263

Prized results from HARPS. Low-mass/habitable/transiting planets orbiting M dwarfs  

NASA Astrophysics Data System (ADS)

Searching for planets around stars with different masses probes the outcome of planetary formation for different initial conditions. The low-mass M dwarfs are also the most frequent stars in our Galaxy and potentially therefore, the most frequent planet hosts. This has motivated our search for planets around M dwarfs with HARPS. That observing program has now run for almost a decade and detected most of the known low-mass planets orbiting M dwarfs (m sin i < 20 M?), including the least massive (GJ581e, msini = 1.9 M?) and the first potentially habitable planets (GJ581c&d GJ667Cc, GJ163c). This proceeding shortly reviews the detections made with HARPS, reports on the occurrence of planets around M dwarfs and how they mesh up with planet formation theory. It also highlights our sensitivity to low-mass habitable planets, the first direct measure of ??, and the recent detection of a transiting planet the size of Uranus.

Bonfils, Xavier; Bouchy, François; Delfosse, X.; Forveille, T.; Gillon, M.; Lovis, C.; Mayor, M.; Neves, V.; Pepe, F.; Perrier, C.; Queloz, D.; Santos, N.; Ségransan, D.; Udry, S.

2013-04-01

264

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

E-print Network

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.

Eric Agol; Jason H. Steffen

2006-10-05

265

The Trojan minor planets  

NASA Astrophysics Data System (ADS)

There are (March, 1988) 3774 minor planets which have received a permanent number. Of these, there are some whose mean distance to the sun is very nearly equal to that of Jupiter, and whose heliocentric longitudes from that planet are about 60°, so that the three bodies concerned (sun, Jupiter, minor planet) make an approximate equilateral triangle. These minor planets, which occur in two distinct groups, one preceding Jupiter and one following, have received the names of the heroes of the Trojan war. This paper concerns the 49 numbered minor planets of this group.

Spratt, Christopher E.

1988-08-01

266

The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars  

E-print Network

In 1992 we began a precision radial velocity (RV) survey for planets around solar-like stars with the Coude Echelle Spectrograph and the Long Camera (CES LC) at the 1.4 m telescope in La Silla (Chile). We have continued the survey with the upgraded CES Very Long Camera (VLC) and HARPS, both at the 3.6 m telescope, until 2007. The observations for 31 stars cover a time span of up to 15 years and the RV precision permit a search for Jupiter analogues. We perform a joint analysis for variability, trends, periodicities, and Keplerian orbits and compute detection limits. Moreover, the HARPS RVs are analysed for correlations with activity indicators (CaII H&K and CCF shape). We achieve a long-term RV precision of 15 m/s (CES+LC, 1992-1998), 9 m/s (CES+VLC, 1999-2006), and 2.8 m/s (HARPS, 2003-2009, including archive data), resp. This enables us to confirm the known planets around Iota Hor, HR 506, and HR 3259. A steady RV trend for Eps Ind A can be explained by a planetary companion. On the other hand, we find ...

Zechmeister, M; Endl, M; Curto, G Lo; Hartman, H; Nilsson, H; Henning, T; Hatzes, A P; Cochran, W D

2012-01-01

267

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

SciTech Connect

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 }.

Endl, Michael; MacQueen, Phillip J.; Cochran, William D. [McDonald Observatory, University of Texas at Austin, Austin, TX 78712 (United States); Brugamyer, Erik J. [Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, Denmark Centre for Star and Planet Formation, University of Copenhagen (Denmark); Rowe, Jason [SETI Institute, Moffett Field, CA 94035 (United States); Lucas, Phillip [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Bryson, Steve; Howell, Steve B.; Borucki, William J.; Caldwell, Douglas; Christiansen, Jessie L.; Haas, Michael R. [NASA-Ames Research Center, Moffett Field, CA 94035 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Hansen, Terese [Niels Bohr Institute, University of Copenhagen (Denmark); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Demory, Brice-Olivier [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Everett, Mark [NOAO, 950 N. Cherry Ave., Tucson, AZ 85719 (United States); Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); and others

2011-11-01

268

Operating an Improved HAT Network to Discover and Characterize Many Planets, from Super-Earths to Super-Jupiters, Transiting Bright Stars  

NASA Astrophysics Data System (ADS)

OBJECTIVES The primary objective of this program is to discover many new extrasolar planets that transit stars bright enough to allow in-depth follow-up studies. This program will focus, in particular, on exploring the large, but poorly studied, populations of long period planets as well as Neptunes and super Earths transiting bright stars. We will also provide accurate initial characterization of the newly discovered exoplanets. METHODS We will accomplish these research objectives by continuing the operation of the highly efficient and successful HATNet project in the period of 2013-2016, exploiting its unique capabilities to discover long period as well as small transiting planets. We also propose to replace our inexpensive front-illuminated CCDs with high quality back-illuminated CCDs so as to achieve 1 millimagnitude photometry at 9 minute cadence over a wide field of view for the brightest stars, as demonstrated by a recent experiment. The CCD upgrade, new observing techniques, and highly optimized reduction of the data will increase HATNet's current efficiency towards finding Neptune-sized planets by a factor of 8. With 38 transiting planets published to date, including two of the five well-characterized Neptune-mass planets, and having received more than 750 citations to date, HATNet is one of the world leaders in their discovery. Without further funding HATNet operations will cease. Our team has established a very well working machinery (equipment, personnel, follow-up tools, and expertise) which represents a significant, and highly cost- efficient investment by NASA. The specific methods and techniques we will use are now fully developed, and include: automated monitoring of all bright stars in selected 8x8 degree star fields; identifying candidate transiting planets based on these observations; and conducting follow-up spectroscopic and photometric observations to confirm and characterize those candidates which are real transiting planets. SIGNIFICANCE/RELEVANCE We expect to discover about 60 new transiting planets around bright stars over the course of program. These planets are expected to span a broad range of parameters, with radii as small as 3 times that of Earth, and orbital periods up to 20 days or longer, and some being in multi-planet systems. Due to the brightness of the host stars, these planets will be suitable for detailed characterization by on-going and future ground and space-based efforts. Notably, based on statistics from the Kepler space mission, small radius and long period planets are now known to be abundant, but are poorly studied, due to the faintness of the host stars in Kepler. We will target bright stars to discover the same population of Neptune and super-Earth sized planets. The new discoveries will also provide present and future NASA missions with suitable targets. This proposal directly addresses the NASA Origins goals of supporting "investigations to detect extra-solar planets" and of "Characterizing extra-solar planets". The proposal will "aid in the detection of new extra-solar planets" and lead to a "better understanding of the origins of planetary systems."

Bakos, Gaspar

269

Gaia's potential for the discovery of circumbinary planets  

E-print Network

The abundance and properties of planets orbiting binary stars - circumbinary planets - are largely unknown because they are difficult to detect with currently available techniques. Results from the Kepler satellite and other studies indicate a minimum occurrence rate of circumbinary giant planets of ~10 %, yet only a handful are presently known. Here, we study the potential of ESA's Gaia mission to discover and characterise extrasolar planets orbiting nearby binary stars by detecting the binary's periodic astrometric motion caused by the orbiting planet. We expect that Gaia will discover hundreds of giant planets around binaries with FGK dwarf primaries within 200 pc of the Sun, if we assume that the giant planet mass distribution and abundance are similar around binaries and single stars. If on the other hand all circumbinary gas giants have masses lower than two Jupiter masses, we expect only four detections. Gaia is critically sensitive to the properties of giant circumbinary planets and will therefore mak...

Sahlmann, Johannes; Martin, David V

2014-01-01

270

The Planets  

NSDL National Science Digital Library

This tool allows users to find when planets are visible in a given year. The years covered by this site are 1900 to 2100. The positions given are for the 1st of the month, at 9 pm, and generally hold true for the entire month. Positions are noted by which constellation the planet is located in. The planets given are Venus, Mars, Jupiter, Saturn, Neptune, Uranus, and Pluto. Additional comments for Venus and Mars note their location and viewing times.

271

Stellar-mass-dependent Disk Structure in Coeval Planet-forming Disks  

Microsoft Academic Search

Previous studies suggest that the planet-forming disks around very low mass stars\\/brown dwarfs may be flatter than those around more massive stars, in contrast to model predictions of larger scale heights for gas-disks around lower-mass stars. We conducted a statistically robust study to determine whether there is evidence for stellar-mass-dependent disk structure in planet-forming disks. We find a statistically significant

László Szucs; Dániel Apai; Ilaria Pascucci; Cornelis P. Dullemond; Cornelis P

2010-01-01

272

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

NASA Technical Reports Server (NTRS)

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.

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

273

Jupiter: Earth's Shield  

NSDL National Science Digital Library

More than 155 planets have been found outside of our solar system since the first discovery in 1995, mostly massive Jupiter-like planets in orbits close to their suns. Now, to find an Earth-like planet, scientists are looking for a planetary setup that is similar to our own, in which a Jupiter-like planet lies a good distance away from its sun. This video segment explores how the arrangement of planets in our solar system may have affected the development of life on Earth and describes how researchers are searching for the right planetary setup. The segment is two minutes one second in length. A background essay and list of discussion questions are also provided.

2011-02-01

274

DIRECTLY IMAGING TIDALLY POWERED MIGRATING JUPITERS  

SciTech Connect

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.

Dong Subo; Katz, Boaz; Socrates, Aristotle [Institute for Advanced Study, Princeton, NJ 08540 (United States)

2013-01-10

275

Constraining Planetary Migration Mechanisms in Systems of Giant Planets  

NASA Astrophysics Data System (ADS)

It was once widely believed that planets formed peacefully in situ in their proto-planetary disks and subsequently remain in place. Instead, growing evidence suggests that many giant planets undergo dynamical rearrangement that results in planets migrating inward in the disk, far from their birthplaces. However, it remains debated whether this migration is caused by smooth planet-disk interactions or violent multi-body interactions. Both classes of model can produce Jupiter-mass planets orbiting within 0.1 AU of their host stars, also known as hot Jupiters. In the latter class of model, another planet or star in the system perturbs the Jupiter onto a highly eccentric orbit, which tidal dissipation subsequently shrinks and circularizes during close passages to the star. We assess the prevalence of smooth vs. violent migration through two studies. First, motivated by the predictions of Socrates et al. (2012), we search for super-eccentric hot Jupiter progenitors by using the ``photoeccentric effect'' to measure the eccentricities of Kepler giant planet candidates from their transit light curves. We find a significant lack of super- eccentric proto-hot Jupiters compared to the number expected, allowing us to place an upper limit on the fraction of hot Jupiters created by stellar binaries. Second, if both planet-disk and multi-body interactions commonly cause giant planet migration, physical properties of the proto-planetary environment may determine which is triggered. We identify three trends in which giant planets orbiting metal rich stars show signatures of planet-planet interactions: (1) gas giants orbiting within 1 AU of metal-rich stars have a range of eccentricities, whereas those orbiting metal- poor stars are restricted to lower eccentricities; (2) metal-rich stars host most eccentric proto-hot Jupiters undergoing tidal circularization; and (3) the pile-up of short-period giant planets, missing in the Kepler sample, is a feature of metal-rich stars and is largely recovered for giants orbiting metal-rich Kepler host stars. These two studies suggest that both disk migration and planet-planet interactions may be widespread, with the latter occurring primarily in metal-rich planetary systems where multiple giant planets can form. Funded by NSF-GRFP DGE-1144152.

Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

2014-01-01

276

Formation of the giant planets  

NASA Technical Reports Server (NTRS)

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.

Lissauer, Jack J.

2006-01-01

277

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

SciTech Connect

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.

Lyra, Wladimir; Mac Low, Mordecai-Mark [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States); Paardekooper, Sijme-Jan, E-mail: wlyra@amnh.or, E-mail: mordecai@amnh.or [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 OWA (United Kingdom)

2010-06-01

278

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 atmospheres of giant planets and T dwarfs. In hotter objects, several P-bearing gases (e.g., P2, PH3, PH 2, PH

Fegley Jr., Bruce

279

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

SciTech Connect

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.

Chang, S.-H.; Gu, P.-G. [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Bodenheimer, P. H. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)

2010-01-10

280

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)  

NASA Astrophysics Data System (ADS)

We report the discovery of one newly confirmed planet (P = 66.06 days, R P = 2.68 ± 0.17 R ?) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R P = 2.15 ± 0.10 R ?) and Kepler-289-c (P = 125.85 days, R P = 11.59 ± 0.10 R ?), 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 * = 1.08 ± 0.02 M ?, R * = 1.00 ± 0.02 R ?, and T 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 ?, 4.0 ± 0.9M ?, and M = 132 ± 17 M ?, 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–3 for a planet of its mass, requiring a substantial H/He atmosphere of 2.1+0.8-0.3% by mass, and joins a growing population of low-mass, low-density planets. .

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

2014-11-01

281

Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing.  

PubMed

In the favoured core-accretion model of formation of planetary systems, solid planetesimals accumulate to build up planetary cores, which then accrete nebular gas if they are sufficiently massive. Around M-dwarf stars (the most common stars in our Galaxy), this model favours the formation of Earth-mass (M(o)) to Neptune-mass planets with orbital radii of 1 to 10 astronomical units (au), which is consistent with the small number of gas giant planets known to orbit M-dwarf host stars. More than 170 extrasolar planets have been discovered with a wide range of masses and orbital periods, but planets of Neptune's mass or less have not hitherto been detected at separations of more than 0.15 au from normal stars. Here we report the discovery of a 5.5(+5.5)(-2.7) M(o) planetary companion at a separation of 2.6+1.5-0.6 au from a 0.22+0.21-0.11 M(o) M-dwarf star, where M(o) refers to a solar mass. (We propose to name it OGLE-2005-BLG-390Lb, indicating a planetary mass companion to the lens star of the microlensing event.) The mass is lower than that of GJ876d (ref. 5), although the error bars overlap. Our detection suggests that such cool, sub-Neptune-mass planets may be more common than gas giant planets, as predicted by the core accretion theory. PMID:16437108

Beaulieu, J-P; Bennett, D P; Fouqué, P; Williams, A; Dominik, M; Jørgensen, U G; Kubas, D; Cassan, A; Coutures, C; Greenhill, J; Hill, K; Menzies, J; Sackett, P D; Albrow, M; Brillant, S; Caldwell, J A R; Calitz, J J; Cook, K H; Corrales, E; Desort, M; Dieters, S; Dominis, D; Donatowicz, J; Hoffman, M; Kane, S; Marquette, J-B; Martin, R; Meintjes, P; Pollard, K; Sahu, K; Vinter, C; Wambsganss, J; Woller, K; Horne, K; Steele, I; Bramich, D M; Burgdorf, M; Snodgrass, C; Bode, M; Udalski, A; Szyma?ski, M K; Kubiak, M; Wieckowski, T; Pietrzy?ski, G; Soszy?ski, I; Szewczyk, O; Wyrzykowski, L; Paczy?ski, B; Abe, F; Bond, I A; Britton, T R; Gilmore, A C; Hearnshaw, J B; Itow, Y; Kamiya, K; Kilmartin, P M; Korpela, A V; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okada, C; Ohnishi, K; Rattenbury, N J; Sako, T; Sato, S; Sasaki, M; Sekiguchi, T; Sullivan, D J; Tristram, P J; Yock, P C M; Yoshioka, T

2006-01-26

282

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

PubMed

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

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

283

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

E-print Network

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.

Sean N. Raymond

2006-05-04

284

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)

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.

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

285

CONSEQUENCES OF THE EJECTION AND DISRUPTION OF GIANT PLANETS  

SciTech Connect

The discovery of Jupiter-mass planets in close orbits about their parent stars has challenged models of planet formation. Recent observations have shown that a number of these planets have highly inclined, sometimes retrograde orbits about their parent stars, prompting much speculation as to their origin. It is known that migration alone cannot account for the observed population of these misaligned hot Jupiters, which suggests that dynamical processes after the gas disk dissipates play a substantial role in yielding the observed inclination and eccentricity distributions. One particularly promising candidate is planet-planet scattering, which is not very well understood in the nonlinear regime of tides. Through three-dimensional hydrodynamical simulations of multi-orbit encounters, we show that planets that are scattered into an orbit about their parent stars with closest approach distance being less than approximately three times the tidal radius are either destroyed or completely ejected from the system. We find that as few as 9 and as many as 12 of the currently known hot Jupiters have a maximum initial apastron for scattering that lies well within the ice line, implying that these planets must have migrated either before or after the scattering event that brought them to their current positions. If stellar tides are unimportant (Q{sub *} {approx}> 10{sup 7}), disk migration is required to explain the existence of the hot Jupiters present in these systems. Additionally, we find that the disruption and/or ejection of Jupiter-mass planets deposits a Sun's worth of angular momentum onto the host star. For systems in which planet-planet scattering is common, we predict that planetary hosts have up to a 35% chance of possessing an obliquity relative to the invariable plane of greater than 90{sup 0}.

Guillochon, James [NASA Earth and Space Science Fellow. (United States); Ramirez-Ruiz, Enrico; Lin, Douglas, E-mail: jfg@ucolick.org [Theoretical Astrophysics Santa Cruz (TASC), Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

2011-05-10

286

The High Albedo of the Hot-Jupiter Kepler7b  

Microsoft Academic Search

Kepler-7b is the least dense extrasolar planet discovered to date. This 4.9-day period hot-Jupiter has a mass of half of Jupiter (0.47 MJ) but a radius 50% larger (1.48 RJ). We present a global analysis of this system including more than 180 high-precision transits and occultations obtained with NASA's Kepler mission. Our best fit to the observations yields a high

Brice-Olivier Demory; S. Seager; H. Kjeldsen

2011-01-01

287

The Nitrogen Constraint on Habitability of Planets around Low Mass M-stars  

NASA Astrophysics Data System (ADS)

The traditional habitable zones around stars are defined based on the stability of liquid water over geological timescales. Being too far away from the stars, the planet would be incapable of maintaining a warm surface and thus no liquid water. Being too close to the star, the planet would experience a 'runaway' greenhouse phase, during which its oceans could be lost quickly, and end up similar to our sister planet, Venus. The definition of tranditional habitable zones does not consider the availability of other elements important for life. All life as we know it needs nitrogen. Our calculations of upper planetary atmospheres show that nitrogen could be lost rapidly from planetary atmospheres with CO2 concentrations lower than certain threshold. This suggests that life on planets around low mass M-stars may be selflimiting, and planets of low mass M-stars are less favorable places to search for life than G- or K-type stars.

Tian, F.

2011-10-01

288

The Nitrogen Constraint on Habitability of Planets of Low Mass M-stars  

NASA Astrophysics Data System (ADS)

The traditional habitable zones around stars are defined based on the stability of liquid water over geological timescales. Being too far away from the stars, the planet would be incapable of maintaining a warm surface and thus no liquid water. Being too close to the star, the planet would experience a 'runaway' greenhouse phase, during which its oceans could be lost quickly, and end up similar to our sister planet, Venus. The definition of tranditional habitable zones does not consider the availability of other elements important for life. All life as we know it needs nitrogen. Our calculations of upper planetary atmospheres show that nitrogen could be lost rapidly from planetary atmospheres with CO2 concentrations lower than certain threshold. This suggests that life on planets around low mass M-stars may be selflimiting, and planets of low mass M-stars are less favorable places to search for life than G- or K-type stars.

Tian, F.

2011-12-01

289

The Nitrogen Constraint on the Habitability of Planets around Low Mass M-stars  

NASA Astrophysics Data System (ADS)

The traditional habitable zones around stars are defined based on the stability of liquid water over geological timescales. Being too far away from the stars, the planet would be incapable of maintaining a warm surface and thus no liquid water. Being too close to the star, the planet would experience a 'runaway' greenhouse phase, during which its oceans could be lost quickly, and end up similar to our sister planet, Venus. The definition of tranditional habitable zones does not consider the availability of other elements important for life. All life as we know it needs nitrogen. Our calculations of upper planetary atmospheres show that nitrogen could be lost rapidly from planetary atmospheres with CO2 concentrations lower than certain threshold. This suggests that life on planets around low mass M-stars may be self-limiting, and planets of low mass M-stars are less favorable places to search for life than G- or K-type stars.

Tian, Feng

2011-09-01

290

Search for Low-Mass Planets Around Late-M Dwarfs Using IRD  

NASA Astrophysics Data System (ADS)

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.

Omiya, Masashi; Sato, Bun'ei; Harakawa, Hiroki; Kuzuhara, Masayuki; Hirano, Teruyuki; Narita, Norio

2014-04-01

291

Jump Start Jupiter  

NSDL National Science Digital Library

This is a kick-off activity about the solar system and Jupiter. Learners will discuss what they know, work in teams to read about the Sun, eight planets, asteroid belt, and the dwarf planet, Pluto. They use their knowledge to create a poster about each object, which can be displayed in the library and used in later activities. This activity is part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

292

A Day on Jupiter (Animation)  

NASA Technical Reports Server (NTRS)

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.

2007-01-01

293

SHORT-DURATION LENSING EVENTS. I. WIDE-ORBIT PLANETS? FREE-FLOATING LOW-MASS OBJECTS? OR HIGH-VELOCITY STARS?  

SciTech Connect

Short-duration lensing events tend to be generated by low-mass lenses or by lenses with high transverse velocities. Furthermore, for any given lens mass and speed, events of short duration are preferentially caused by nearby lenses (mesolenses) that can be studied in detail, or else by lenses so close to the source star that finite-source-size effects may be detected, yielding information about both the Einstein ring radius and the surface of the lensed star. Planets causing short-duration events may be in orbits with any orientation, and may have semimajor axes smaller than 1 AU, or they may reach the outer limits of their planetary systems, in the region corresponding to the solar system's Oort Cloud. They can have masses larger than Jupiter's or smaller than Pluto's. Lensing therefore has a unique potential to expand our understanding of planetary systems. A particular advantage of lensing is that it can provide precision measurements of system parameters, including the masses of and projected separation between star and planet. We demonstrate how the parameters can be extracted and show that a great deal can be learned. For example, it is remarkable that the gravitational mass of nearby free-floating planet-mass lenses can be measured by complementing observations of a photometric event with deep images that detect the planet itself. A fraction of short events may be caused by high-velocity stars located within a kiloparsec. Many high-velocity lenses are likely to be neutron stars that received large natal kicks. Other high-speed stars may be members of the halo population. Still others may be hypervelocity stars that have been ejected from the Galactic center, or runaway stars escaped from close binaries, possibly including the progenitor binaries of Type Ia supernovae.

Di Stefano, Rosanne [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-08-01

294

Planet formation around low mass stars: the moving snow line and super-Earths  

E-print Network

We develop a semi-analytic model for planet formation during the pre-main sequence contraction phase of a low mass star. During this evolution, the stellar magnetosphere maintains a fixed ratio between the inner disk radius and the stellar radius. As the star contracts at constant effective temperature, the `snow line', which separates regions of rocky planet formation from regions of icy planet formation, moves inward. This process enables rapid formation of icy protoplanets that collide and merge into super-Earths before the star reaches the main sequence. The masses and orbits of these super-Earths are consistent with super-Earths detected in recent microlensing experiments.

Grant M. Kennedy; Scott J. Kenyon; Benjamin C. Bromley

2006-09-06

295

Jupiter and Super-Earth embedded in a gaseous disc  

E-print Network

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.

E. Podlewska; E. Szuszkiewicz

2007-12-19

296

Planet Traps and Planetary Cores: Origins of the Planet-Metallicity Correlation  

NASA Astrophysics Data System (ADS)

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.

Hasegawa, Yasuhiro; Pudritz, Ralph E.

2014-10-01

297

Jupiter - friend or foe? II: the Centaurs  

NASA Astrophysics Data System (ADS)

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.

Horner, J.; Jones, B. W.

2009-04-01

298

Jupiter: its captured satellites.  

PubMed

Because of the small size and irregular orbits of the seven outer satellites of Jupiter, it is often assumed that they were derived by capture. The conditions whereby Jupiter can capture satellites have therefore been examined. Relationships derived on the basis of the three-body problem for planets in elliptical orbits enable the dimensions of the capture orbits around Jupiter to be calculated. It is found that Jupiter may capture satellites through the inner Lagrangian point when at perihelion or at aphelion. Captures at perihelion should give rise to satellites in direct orbits of 11.48 x 10(6) kilometers and capture at aphelion to retrograde orbits of 21.7 x 10(6) kilometers. The correspondence with the seven outer satellites suggests that Jupiter VI, VIl, and X in direct orbits at 11.47, 11.74, and 11.85 x 10(6) kilometers were captured at Jupiter perihelion, whereas Jupiter VIII, IX, XI, and XII in retrograde orbits of 23.5, 23.7, 22.5, and 21.2 x 10(6) kilometers were captured when Jupiter was at aphelion. Examination of the precapture orbits indicates that the seven outer satellites were derived from the asteroid belt. PMID:17812191

Bailey, J M

1971-08-27

299

A Comparison of Numerical Simulations of Disk-Planet Interactions  

Microsoft Academic Search

We study the gravitational interaction between a protoplanetary disk and an embedded high-mass planet using several grid-based and smoothed particle hydrodynamics (SPH) schemes. Jupiter and Neptune mass planets are kept on a fixed circular orbit during several hundred orbital periods. We run tests for inviscid and viscous disks with Navier-Stokes viscosity of nu=10-5. We find good agreement between our codes.

Miguel De Val-Borro; R. G. Edgar; P. Artymowicz; P. Ciecielag; P. Cresswell; G. D'Angelo; E. J. Delgado-Donate; G. Dirksen; S. Fromang; A. Gawryszczak; H. Klahr; W. Kley; F. Masset; G. Mellema; R. Nelson; S. J. Paardekooper; A. Peplinski; A. Pierens; T. Plewa; K. Rice; C. Schäfer; R. Speith

2007-01-01

300

Extrasolar planet population synthesis. I. Method, formation tracks, and mass-distance distribution  

NASA Astrophysics Data System (ADS)

Context: With the high number of extrasolar planets discovered by now, it has become possible to use the properties of this planetary population to constrain theoretical formation models in a statistical sense. This paper is the first in a series in which we carry out a large number of planet population synthesis calculations within the framework of the core accretion scenario. We begin the series with a paper mainly dedicated to the presentation of our approach, but also the discussion of a representative synthetic planetary population of solar like stars. In the second paper we statistically compare the subset of detectable planets to the actual extrasolar planets. In subsequent papers, we shall extend the range of stellar masses and the properties of protoplanetary disks. Aims: The last decade has seen a large observational progress in characterizing both protoplanetary disks, and extrasolar planets. Concurrently, progress was made in developing complex theoretical formation models. The combination of these three developments allows a new kind of study: the synthesis of a population of planets from a model, which is compared with the actual population. Our aim is to obtain a general overview of the population, to check if we quantitatively reproduce the most important observed properties and correlations, and to make predictions about the planets that are not yet observable. Methods: Based as tightly as possible on observational data, we have derived probability distributions for the most important initial conditions for the planetary formation process. We then draw sets of initial conditions from these distributions and obtain the corresponding synthetic planets with our formation model. By repeating this step many times, we synthesize the populations. Results: Although the main purpose of this paper is the description of our methods, we present some key results: we find that the variation of the initial conditions in the limits occurring in nature leads to the formation of planets of wide diversity. This formation process is best visualized in planetary formation tracks in the mass-semimajor axis diagram, where different phases of concurrent growth and migration can be identified. These phases lead to the emergence of sub-populations of planets distinguishable in a mass-semimajor axis diagram. The most important ones are the “failed cores”, a vast group of core-dominated low mass planets, the “horizontal branch”, a sub-population of Neptune mass planets extending out to 6 AU, and the “main clump”, a concentration of giant gaseous planets at around 0.3-2 AU.

Mordasini, C.; Alibert, Y.; Benz, W.

2009-07-01

301

Connecting planetary and stellar heavy element enrichement: A new window into planet formation  

NASA Astrophysics Data System (ADS)

Planets are formed from the same materials as their parent stars, yet emerge with distinctly non-stellar compositions. This is clear within the solar system, where we can see compositional patterns, yet we have only a small sample size that may not be representative of exoplanet populations. Here we make an important step to connect giant planet composition to stellar composition for transiting planets. We study a population of relatively cool transiting gas giants below 1000 K, which are not affected by the hot Jupiter radius anomaly. Using planetary thermal evolution models, for these planets we can ascertain their bulk metallicity Z_planet from their masses, radii, and ages. We compare these values to Z_star, derived from stellar [Fe/H], to derive giant planet metal enrichments, Z_planet/Z_star, for a population of nearly 40 gas giants. This is the first large sample of planets for which planetary bulk composition can be compared to stellar composition. We show a number of trends of Z_planet/Z_star with planetary mass and stellar [Fe/H]. These trends place new constraints on planet formation and population synthesis models and show that the enrichment of Jupiter and Saturn fit well within the exoplanet population. Intriguingly, we show that metal-enriched gas giants persist to masses of ~10 M_Jupiter, near the brown dwarf mass boundary, which suggests observational differences between these "super Jupiters" in orbit around stars and low-mass brown dwarfs. We suggest that new knowledge on the star-planet composition connection will be gained by relating Z_planet/Z_star to the stellar abundances of other planet forming elements, like C, O, Si, and Mg.

Fortney, Jonathan J.; Thorngren, Daniel; Teske, Johanna K.; Hinkel, Natalie R.

2014-11-01

302

ORBITAL MIGRATION OF INTERACTING LOW-MASS PLANETS IN EVOLUTIONARY RADIATIVE TURBULENT MODELS  

SciTech Connect

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.

Horn, Brandon; Mac Low, Mordecai-Mark [Department of Astronomy, Columbia University, 550 West 120th St, New York, NY 10027 (United States); Lyra, Wladimir [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States); Sandor, Zsolt, E-mail: bhorn@astro.columbia.edu, E-mail: wlyra@amnh.org, E-mail: mordecai@amnh.org, E-mail: zsolt.sandor@uibk.ac.at [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117, Heidelberg (Germany)

2012-05-01

303

Jupiter Polar Winds Movie  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

304

THE EFFECT OF PLANET-PLANET SCATTERING ON THE SURVIVAL OF EXOMOONS  

SciTech Connect

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.

Gong Yanxiang; Zhou Jilin; Xie Jiwei [Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093 (China); Wu Xiaomei, E-mail: zhoujl@nju.edu.cn, E-mail: yxgong@nju.edu.cn [College of Physics and Electronic Engineering, Taishan University, Taian 271021 (China)

2013-05-20

305

The Effect of Planet-Planet Scattering on the Survival of Exomoons  

NASA Astrophysics Data System (ADS)

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.

Gong, Yan-Xiang; Zhou, Ji-Lin; Xie, Ji-Wei; Wu, Xiao-Mei

2013-05-01

306

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

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.

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

307

Direct imaging of multiple planets orbiting the star HR 8799  

SciTech Connect

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.

Marois, C; Macintosh, B; Barman, T; Zuckerman, B; Song, I; Patience, J; Lafreniere, D; Doyon, R

2008-10-14

308

Cold Hole Over Jupiter's Pole  

NASA Technical Reports Server (NTRS)

Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.

These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.

The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.

The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.

The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.

These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at frequencies sensitive to the polar haze were taken at frequent intervals from June to October 1999. They show that the quasi-hexagonal structure rotates slowly eastward at 1.2 degrees of longitude per day, a rate consistent with the average wind speeds measured from movement of visible clouds.

Scientists studying the Earth's atmosphere are interested in these results because Jupiter's atmosphere provides a natural laboratory in which models of the polar vortex phenomenon can be studied under different conditions - for example, without the interference of topography. Of particular interest but yet unknown is how deep into Jupiter's troposphere the phenomenon extends. The answer to this question might be supplied by instrumentation on a polar orbiter mission at Jupiter.

These images were taken as part of a program to support NASA's Galileo spacecraft reconnaissance of Jupiter. The Infrared Telescope Facility is on the summit of Hawaii's Mauna Kea and is operated by the University of Hawaii under a cooperative agreement with NASA. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. The telescope is managed by the Space Telescope Science Institute, Baltimore, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The California Institute of Technology, Pasadena manages JPL for NASA.

2002-01-01

309

Direct imaging search for planets around low-mass stars and spectroscopic characterization of young exoplanets  

NASA Astrophysics Data System (ADS)

Low--mass stars between 0.1--0.6 M? are the most abundant members our galaxy and may be the most common sites of planet formation, but little is known about the outer architecture of their planetary systems. We have carried out a high-contrast adaptive imaging search for gas giant planets between 1--13 MJup around 122 newly identified young M dwarfs in the solar neighborhood ( ? 35 pc). Half of our targets are younger than 145 Myr, and 90% are younger than 580 Myr. After removing 39 resolved stellar binaries, our homogeneous sample of 83 single young M dwarfs makes it the largest imaging search for planets around low--mass stars to date. Our H- and K- band coronagraphic observations with Subaru/HiCIAO and Keck/NIRC2 achieve typical contrasts of 9--13 mag and 12--14 mag at 100, respectively, which corresponds to limiting masses of ˜1--10 M Jup at 10--30 AU for most of our sample. We discovered four brown dwarfs with masses between 25--60 MJup at projected separations of 4--190 AU. Over 100 candidate planets were discovered, nearly all of which were found to be background stars from follow-up second epoch imaging. Our null detection of planets nevertheless provides strong statistical constraints on the occurrence rate of giant planets around M dwarfs. Assuming circular orbits and a logarithmically-flat power law distribution in planet mass and semi--major axis of the form d 2N=(dloga dlogm) infinity m0 a0, we measure an upper limit (at the 95% confidence level) of 8.8% and 12.6% for 1--13 MJup companions between 10--100 AU for hot start and cold start evolutionary models, respectively. For massive gas giant planets in the 5--13 M Jup range like those orbiting HR 8799, GJ 504, and beta Pictoris, we find that fewer than 5.3% (7.8%) of M dwarfs harbor these planets between 10--100 AU for a hot start (cold start) formation scenario. Our best constraints are for brown dwarf companions; the frequency of 13--75 MJup companions between (de--projected) physical separations of 10--100 AU is 2.1+2.1-1.2 %. Altogether, our results show that gas giant planets, especially massive ones, are rare in the outskirts of M dwarf planetary systems. If disk instability is a viable way to form planets, our constraints for the most common type of star imply that overall it is an inefficient mechanism.

Bowler, Brendan Peter

310

Planet Party  

NSDL National Science Digital Library

Learners and their families are encouraged to go outside on a clear evening and view the sky to see the planets for themselves. Using sky charts and other resources, and possibly in partnership with a local astronomical society, children navigate the night sky and view planets with the naked eye and binoculars or telescopes. This activity is part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

311

A Massive Core in Jupiter Predicted From First-Principles Simulations  

E-print Network

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.

B. Militzer; W. B. Hubbard; J. Vorberger; I. Tamblyn; S. A. Bonev

2008-07-26

312

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

ERIC Educational Resources Information Center

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…

Bates, Alan

2013-01-01

313

Detection of Extrasolar Planets by Transit Photometry  

NASA Technical Reports Server (NTRS)

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.

Borucki, William; Koch, David; Webster, Larry; Dunham, Edward; Witteborn, Fred; Jenkins, Jon; Caldwell, Douglas; Showen, Robert; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

314

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)

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.

Isaacson, Howard T.; Marcy, G.; Rowe, J.; Kepler Team

2013-06-01

315

Kepler-424 b: A "Lonely" Hot Jupiter That Found A Companion  

E-print Network

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-d orbit accompanied by a more massive outer companion in an eccentric (e=0.3) 223-d orbit. The outer giant planet, Kepler-424c, is not detected to transit 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, the appear to be "lonely" (e.g. Steffen et al.~2012). This might be a consequence of a highly dynamical past of these systems. The Kepler-424 planetary system is a system with a hot Jupiter in a multiple system, similar to upsilon Andromedae. We also pres...

Endl, Michael; 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

2014-01-01

316

FORMATION OF GIANT PLANETS BY DISK INSTABILITY ON WIDE ORBITS AROUND PROTOSTARS WITH VARIED MASSES  

SciTech Connect

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.

Boss, Alan P., E-mail: boss@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

2011-04-10

317

Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism  

E-print Network

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.

M. Nagasawa; S. Ida; T. Bessho

2008-01-09

318

Roche Lobes and the Evolution of Hot Jupiters  

NASA Astrophysics Data System (ADS)

Hot Jupiters are characterized by an inflated atmosphere as a result of their close proximity to their parent star. Because of their gaseous atmosphere and small semi-major axes, it is possible that these systems may undergo Roche lobe overflow at some point during their evolution. Using the updated Roche lobe calculations from Sepinsky et al. (2010) which incorporate the planet’s rotation rate and eccentricity, we calculated the filling fraction of all of the planets in the exoplanet database (exoplanet.eu) as of July 11, 2012. The filling fraction combines semi-major axis, stellar mass, planetary mass, eccentricity, and rotation rate to determine how close a planet is to filling its Roche lobe. After calculating the filling fraction, we selected the 5 planets with the greatest filling fraction that fit the general parameters of a hot Jupiter. We also took the 5 systems with the greatest eccentricity because high eccentricity is an indicator of the possibility for Roche lobe overflow at periastron. We then isolated and manipulated each parameter of the likely systems to determine what adjustments would have to take place in order for the system to have undergone Roche lobe overflow at some point during its evolution. The study of these planets and their evolution will give us a better perspective on the creation and evolution of planetary systems.

Salmon, Rachel; Sepinsky, J. F.

2013-01-01

319

Global Structure and Dynamics of Jupiter's Magnetosphere  

NASA Astrophysics Data System (ADS)

The structure and dynamics of Jupiter's magnetosphere are primarily driven by the strong internal source of plasma from Io. Coupling to Jupiter's ionosphere keeps the iogenic plasma rotating with the planet's 10 hour spin period to distances of ~20-30 Rj. Centrifugal forces confine the sulfur/oxygen dominated plasma to an equatorial plasmasheet. The plasma is believed to move radially outwards (on timescales of 10s of days) via the diffusive process of flux tube interchange. Beyond ~20-30 Rj the coupling to the rotation breaks down, driving strong currents along the magnetic field. The equatorial confinement of the plasma means that there is a lack if current carriers at high latitudes leading to development of potential structures. Intense auroral emissions indicate fluxes of electrons are accelerated into Jupiter's atmosphere. Beyond ~20-30 Rj the plasma continues to rotate with Jupiter, albeit sub-corotation rates. At ~60 Rj the outflow reaches the local Alfven speed and the plasma spirals (advection) away from the planet and down the magnetotail. Unlike the Earth's magnetosphere where reconnection between the IMF and the planetary field drives large scale convective motions, we believe the solar wind interaction with Jupiter's high-beta magnetosphere is via a viscous interaction mediated by Kelvin-Helmholtz instabilities in a low-latitude boundary layer. Mass and momentum of the solar wind are transferred across the magnetopause in an interaction region that thickens down the flanks. Maxwell stresses from the solar wind interaction at the magnetopause drive anti-sunward flows down the magnetotail. This paper summarizes the structure and dynamics of the magnetosphere resulting from this viscous interaction with the solar wind and discusses the observational evidence from auroral emissions and spacecraft data.

Bagenal, Fran; Delamere, Peter

2010-05-01

320

Diffusive Migration of Low-Mass Proto-planets in Turbulent Disks  

E-print Network

Torque fluctuations due to magnetorotational turbulence in proto-planetary disks may greatly influence the migration patterns and survival probabilities of nascent planets. Provided that the turbulence is a stationary stochastic process with finite amplitude and correlation time, the resulting diffusive migration can be described with a Fokker-Planck equation, which we reduce to an advection-diffusion equation. We calibrate the coefficients with existing turbulent-disk simulations and mean-migration estimates, and solve the equation both analytically and numerically. Diffusion tends to dominate over advection for planets of low-mass and those in the outer regions of proto-planetary disks, whether they are described by the Minimum Mass Solar Nebula (MMSN) or by T-Tauri alpha disks. Diffusion systematically reduces the lifetime of most planets, yet it allows a declining fraction of them to survive for extended periods of time at large radii. Mean planet lifetimes can even be formally infinite (e.g. in an infinite steady MMSN), though median lifetimes are always finite. Surviving planets may linger near specific radii where the combined effects of advection and diffusion are minimized, or at large radii, depending on model specifics. The stochastic nature of migration in turbulent disks challenges deterministic planet formation scenarios and suggests instead that a wide variety of planetary outcomes are possible from similar initial conditions. This would contribute to the diversity of (extrasolar) planetary systems.

Eric T. Johnson; Jeremy Goodman; Kristen Menou

2006-03-09

321

The Effect of Planets Beyond the Ice Line on the Accretion of Volatiles by Habitable-zone Rocky Planets  

NASA Astrophysics Data System (ADS)

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 ? to 1 M 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.

Quintana, Elisa V.; Lissauer, Jack J.

2014-05-01

322

Terrestrials Dwarf Planets  

E-print Network

Terrestrials Gas Giants Ice Giants Dwarf Planets The Solar System #12;Neptune Uranus Saturn Jupiter & Helium atmospheres. #12;The Dwarf Planets are a new class of Solar System objects defined by the IAU Dwarf planets can have eccentric and highly inclined orbits. #12;The Solar System has 7 Giant Moons

Gaudi, B. Scott

323

JUPITER AND SPEED OF LIGHT Author: Jaka Klement  

E-print Network

eight relatively solitary planets whose orbits are almost circular and lie within an ecliptic plane an orbit every 11.86 years. Jupiter's rotation is the fastest of all the Solar System's planets, completing................................................................................................................................14 #12;3 1. INTRODUCTION (ABOUT JUPITER) The Solar Systemconsists of the Sun and planets and comets

Â?umer, Slobodan

324

The Kepler Mission: Search for Habitable Planets  

NASA Technical Reports Server (NTRS)

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.

Borucki, William; Likins, B.; DeVincenzi, Donald L. (Technical Monitor)

1998-01-01

325

The HARPS search for southern extra-solar planets. VI. A Neptune-mass planet around the nearby M dwarf Gl 581  

E-print Network

We report the discovery of a Neptune-mass planet around Gl 581 (M3V, M = 0.31 Msol), based on precise Doppler measurements with the HARPS spectrograph at La Silla Observatory. The radial velocities reveal a circular orbit of period P = 5.366 days and semi-amplitude K1 = 13.2 m/s. The resulting minimum mass of the planet (m2 sin i) is only 0.052 Mjup = 0.97 Mnep = 16.6 Mearth making Gl 581b one of the lightest extra-solar planet known to date. The Gl 581 planetary system is only the third centered on an M dwarf, joining the Gl 876 three-planet system and the lone planet around Gl 436. Its discovery reinforces the emerging tendency of such planets to be of low mass, and found at short orbital periods. The statistical properties of the planets orbiting M dwarfs do not seem to match a simple mass scaling of their counterparts around solar-type stars.

X. Bonfils; T. Forveille; X. Delfosse; S. Udry; M. Mayor; C. Perrier; F. Bouchy; F. Pepe; D. Queloz; J. -L. Bertaux

2005-09-08

326

Jupiter's Tropospheric Thermal Emission II: Power Spectrum Analysis and Wave Search  

E-print Network

Jupiter's Tropospheric Thermal Emission II: Power Spectrum Analysis and Wave Search Joseph, Jupiter jovian planets, Atmosphere clouds, Jupiter jupiter, atmosphere, Dynamics infrared observations, Jupiter Revision 3.2: 16:31 19 June 1996 1 Harrington et al. #12; Proposed running heads: Left: Harrington

Harrington, Joe

327

ARTIST'S CONCEPT -- 'HOT JUPITER' AROUND THE STAR HD 209458  

NASA Technical Reports Server (NTRS)

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)

2002-01-01

328

In Search of Planets and Life around Other Stars  

Microsoft Academic Search

The discovery of over a dozen low-mass companions to nearby stars has intensified scientific and public interest in a longer term search for habitable planets like our own. However, the nature of the detected companions, and in particular whether they resemble Jupiter in properties and origin, remains undetermined.

Jonathan I. Lunine

1999-01-01

329

The distribution of the spin angular momentum of the planets  

Microsoft Academic Search

It is noted that a current line of thought concerning the formation of the planetary system suggests the existence of giant gaseous protoplanets with mass and composition similar to the present day Jupiter, though with a much larger radius and consequently lower density. It is therefore shown to be feasible that all the planets could have originated from similar giant

I. P. Williams; S. K. Bhattacharjee

1979-01-01

330

In search of planets and life around other stars  

PubMed Central

The discovery of over a dozen low-mass companions to nearby stars has intensified scientific and public interest in a longer term search for habitable planets like our own. However, the nature of the detected companions, and in particular whether they resemble Jupiter in properties and origin, remains undetermined. PMID:10318886

Lunine, Jonathan I.

1999-01-01

331

Taxonomy of the extrasolar planet  

E-print Network

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...

Plávalová, E

2011-01-01

332

A Neptune-Mass Planet Orbiting the Nearby M Dwarf GJ 436  

E-print Network

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

Paul Butler; Steven S. Vogt; Geoffrey W. Marcy; Debra A. Fischer; Jason T. Wright; Gregory W. Henry; Greg Laughlin; Jack Lissauer

2004-08-31

333

Jupiter: Friend or Foe  

NASA Astrophysics Data System (ADS)

We have now completed the first detailed study on the effect of Jupiter's mass on the impact rate of the three types of potentially hazardous objects - the Near Earth Asteroids, the Short Period Comets, and the Long Period Comets.

Horner, J. A.; Jones, B. W.

2010-04-01

334

The Fate of Scattered Planets  

NASA Astrophysics Data System (ADS)

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.

Bromley, Benjamin C.; Kenyon, Scott J.

2014-12-01

335

Warm Jupiters Need Close "Friends" for High-eccentricity Migration—a Stringent Upper Limit on the Perturber's Separation  

NASA Astrophysics Data System (ADS)

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 (lsim 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.

Dong, Subo; Katz, Boaz; Socrates, Aristotle

2014-01-01

336

Exploring the Diversity of Extrasolar Planet Atmospheres  

NASA Astrophysics Data System (ADS)

The detection and characterization of the atmosphere of a habitable, Earthlike planet is a primary goal in the study of extrasolar planets. Until candidates suitable for such characterization are discovered, observations of larger, hotter, and more massive planets must be used to refine observational techniques and inform exoplanetary atmosphere models, while producing new discoveries exciting in their own right. I will present three new results which challenge our current understanding of more massive extrasolar planets, and represent steps toward characterizing future exo-earths. First, I will present new spectrally resolved observations of the extremely hot Jupiter WASP-12b, which has been claimed to be unusually carbon-rich. Our results, which are also the first to correct WASP-12b's emission for the photometric dilution of a nearby M dwarf, strongly disagree with current carbon-rich models and suggests a nearly isothermal planetary photosphere. Thus detailed compositional analysis will rely on transmission spectroscopy rather than emission measurements. Next, our recent survey of 24 micron thermal phase curves of several other nearby hot Jupiters shows that these planets exhibit strikingly dissimilar recirculation of the incident stellar flux. These different heat redistribution patterns (in spite of the planets' similar equilibrium temperatures) demonstrate the continuing challenge of a robust classification scheme for hot Jupiters. Finally, I will also present first results from our observations of the recently discovered warm Uranus GJ 3470b. This planet's bright host star and deep transit make it the best cool, low-mass planet for detailed atmospheric characterization, and it will quickly become a touchstone object in the study of successively smaller, cooler, and more Earthlike planets.

Crossfield, Ian J.; Hansen, B. M.; Barman, T. S.; Harrington, J.; Knutson, H.; Vican, L.

2013-01-01

337

Exobiology, Jupiter and life.  

NASA Technical Reports Server (NTRS)

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.

Molton, P. M.

1972-01-01

338

A Search for Companions in Kepler's Hot Jupiter Systems  

NASA Astrophysics Data System (ADS)

The presence or absence of additional, short-period planets in hot Jupiter systems is an important observational constraint on models of planet formation and dynamical evolution. Among the over 1000 Kepler exoplanet candidates is a large number of hot Jupiter candidates. We present results from a search for additional planets in these systems through a combination of photometric, geometric, and dynamical (TTV) probes. The results of this search may provide useful insight into the histories and orbital architectures of hot Jupiter systems.

Steffen, Jason H.; Holman, M.; Borucki, W. J.; Koch, D. G.; Kepler Science Team

2011-05-01

339

Very low mass stars, black dwarfs and planets  

Microsoft Academic Search

Hydrogen-rich stars of very low mass (M ? 0.08M?) never go through hydrogenburning thermonuclear reactions and, in a time scale much shorter than the age of the Galaxy, become completely degenerate objects or black dwarfs. The number of the very-low-mass (VLM) black dwarfs is expected to be very large and they are likely to make a significant contribution to the

Shiv S. Kumar

1994-01-01

340

Interior Phase Transformations and Mass-Radius Relationships of Silicon-Carbon Planets  

NASA Astrophysics Data System (ADS)

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 Si2C and SiC2 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.

Wilson, Hugh F.; Militzer, Burkhard

2014-09-01

341

Orbits and Masses of the Satellites of the Dwarf Planet Haumea (2003 EL61)  

Microsoft Academic Search

Using precise relative astrometry from the Hubble Space Telescope and the W. M. Keck Telescope, we have determined the orbits and masses of the two dynamically interacting satellites of the dwarf planet (136108) Haumea, formerly 2003 EL61. The orbital parameters of Hi'iaka, the outer, brighter satellite, match well the previously derived orbit. On timescales longer than a few weeks, no

Darin Ragozzine; M. E. Brown

2009-01-01

342

Predictions for the frequency and orbital radii of massive extrasolar planets  

E-print Network

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.

Philip J. Armitage; Mario Livio; S. H. Lubow; J. E. Pringle

2002-03-29

343

Orbits and Interiors of Planets  

NASA Astrophysics Data System (ADS)

The focus of this thesis is a collection of problems of timely interest in orbital dynamics and interior structure of planetary bodies. The first three chapters are dedicated to understanding the interior structure of close-in, gaseous extrasolar planets (hot Jupiters). In order to resolve a long-standing problem of anomalously large hot Jupiter radii, we proposed a novel magnetohydrodynamic mechanism responsible for inflation. The mechanism relies on the electro-magnetic interactions between fast atmospheric flows and the planetary magnetic field in a thermally ionized atmosphere, to induce electrical currents that flow throughout the planet. The resulting Ohmic dissipation acts to maintain the interior entropies, and by extension the radii of hot Jupiters at an enhanced level. Using self-consistent calculations of thermal evolution of hot Jupiters under Ohmic dissipation, we demonstrated a clear tendency towards inflated radii for effective temperatures that give rise to significant ionization of K and Na in the atmosphere, a trend fully consistent with the observational data. Furthermore, we found that in absence of massive cores, low-mass hot Jupiters can over-flow their Roche-lobes and evaporate on Gyr time-scales, possibly leaving behind small rocky cores. Chapters four through six focus on the improvement and implications of a model for orbital evolution of the solar system, driven by dynamical instability (termed the "Nice" model). Hydrodynamical studies of the orbital evolution of planets embedded in protoplanetary disks suggest that giant planets have a tendency to assemble into multi-resonant configurations. Following this argument, we used analytical methods as well as self-consistent numerical N-body simulations to identify fully-resonant primordial states of the outer solar system, whose dynamical evolutions give rise to orbital architectures that resemble the current solar system. We found a total of only eight such initial conditions, providing independent constraints for the solar system's birth environment. Next, we addressed a significant drawback of the original Nice model, namely its inability to create the physically unique, cold classical population of the Kuiper Belt. Specifically, we showed that a locally-formed cold belt can survive the transient instability, and its relatively calm dynamical structure can be reproduced. The last four chapters of this thesis address various aspects and consequences of dynamical relaxation of planetary orbits through dissipative effects as well as the formation of planets in binary stellar systems. Using octopole-order secular perturbation theory, we demonstrated that in multi-planet systems, tidal dissipation often drives orbits onto dynamical "fixed points," characterized by apsidal alignment and lack of periodic variations in eccentricities. We applied this formalism towards investigating the possibility that the large orbital eccentricity of the transiting Neptune-mass planet Gliese 436b is maintained in the face of tidal dissipation by a second planet in the system and computed a locus of possible orbits for the putative perturber. Following up along similar lines, we used various permutations of secular theory to show that when applied specifically to close-in low-mass planetary systems, various terms in the perturbation equations become separable, and the true masses of the planets can be solved for algebraically. In practice, this means that precise knowledge of the system's orbital state can resolve the sin( i) degeneracy inherent to non-transiting planets. Subsequently, we investigated the onset of chaotic motion in dissipative planetary systems. We worked in the context of classical secular perturbation theory, and showed that planetary systems approach chaos via the so-called period-doubling route. Furthermore, we demonstrated that chaotic strange attractors can exist in mildly damped systems, such as photo-evaporating nebulae that host multiple planets. Finally, we considered planetary formation in highly inclined binary systems,

Batygin, Konstantin

2012-05-01

344

Oligarchic and giant impact growth of terrestrial planets in the presence of gas giant planet migration  

E-print Network

We present the results of N--body simulations which examine the effect that gas giant planet migration has on the formation of terrestrial planets. The models incorporate a 0.5 Jupiter mass planet undergoing type II migration through an inner protoplanet--planetesimal disk, with gas drag included. Each model is initiated with the inner disk being at successively increased levels of maturity, so that it is undergoing either oligarchic or giant impact style growth as the gas giant migrates. In all cases, a large fraction of the disk mass survives the passage of the giant, either by accreting into massive terrestrial planets shepherded inward of the giant, or by being scattered into external orbits. Shepherding is favored in younger disks where there is strong dynamical friction from planetesimals and gas drag is more influential, whereas scattering dominates in more mature disks where dissipation is weaker. In each scenario, sufficient mass is scattered outward to provide for the eventual accretion of a set of terrestrial planets in external orbits, including within the system's habitable zone. An interesting result is the generation of massive, short period, terrestrial planets from compacted material pushed ahead of the giant. These planets are reminiscent of the short period Neptune mass planets discovered recently, suggesting that such `hot Neptunes' could form locally as a by-product of giant planet migration.

Martyn J. Fogg; Richard P. Nelson

2005-07-07

345

Masses and Orbital Inclinations of Planets in the PSR B1257+12 System  

Microsoft Academic Search

We present measurements of the true masses and orbital inclinations of the two Earth-mass planets in the PSR B1257+12 system, based on the analysis of their mutual gravitational perturbations detectable as microsecond variations of the arrival times of radio pulses from the pulsar. The 6.2 ms pulsar, PSR B1257+12, has been regularly timed with the Arecibo telescope since late 1990.

Maciej Konacki; Alex Wolszczan

2003-01-01

346

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

We report the discovery of one newly confirmed planet ($P=66.06$ days, $R_{\\rm{P}}=2.68\\pm0.17R_\\oplus$) and mass determinations of two previously validated Kepler planets, Kepler-289 b ($P=34.55$ days, $R_{\\rm{P}}=2.15\\pm0.10R_\\oplus$) and Kepler-289-c ($P=125.85$ days, $R_{\\rm{P}}=11.59\\pm0.10R_\\oplus$), 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 ($\\sim1.3%$), 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 ($\\sim1$ Gyr as determined by isochrones and gyrochronology), Sun-like star with $M_*=1.08\\pm0.02M_\\odot$, $R_*=1.00\\pm0.02R_\\odot$, and $T_{\\rm{eff}}=5990\\pm38$ K. The middle planet's large TTV amplitude ($\\sim5$ hours) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allo...

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

2014-01-01

347

Too Little, Too Late: How the Tidal Evolution of Hot Jupiters Affects Transit Surveys of Clusters  

NASA Technical Reports Server (NTRS)

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.

Debes, John H.; Jackson, Brian

2010-01-01

348

TOO LITTLE, TOO LATE: HOW THE TIDAL EVOLUTION OF HOT JUPITERS AFFECTS TRANSIT SURVEYS OF CLUSTERS  

SciTech Connect

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.

Debes, John H.; Jackson, Brian [NASA Postdoctoral Program Fellow. (United States)

2010-11-10

349

Jiggly Jupiter  

NSDL National Science Digital Library

Learners will build edible models of Jupiter and Earth to compare their sizes and illustrate their internal layers. They discuss how the Juno mission will infer details about Jupiter's interior by measuring its gravity field and magnetic field. This activity is part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

350

EXTRASOLAR PLANETS Awhiffofmethane  

E-print Network

- pheres in our Solar System: those of Earth, Mars, Titan and the gas giants, Jupiter, Saturn, Uranus planetary formation, evolution, weather, photochemistry and -- in the case of Earth -- life. We have amorerobust estimateof itsabun- dance. The planet is a `hot Jupiter' that orbits only 0.03 Earth­Sun distances

351

The interior structure of the giant planets  

Microsoft Academic Search

An overview of the principal ideas and data pertaining to the construction of models of the interior structure of Jupiter, Saturn, Uranus, and Neptune is presented. Topics discussed include: the concept of Jupiter and Saturn as planets with hydrogenic crusts; the theory of the figure of rotating planets in hydrostatic equilibrium; a gas-liquid dynamic model of the giant planets; analysis

V. N. Zharkov

1991-01-01

352

Atmospheric escape from hot Jupiters  

Microsoft Academic Search

The extra-solar planet HD 209458b 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 HD 209458b is

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

2004-01-01

353

The Effects of Planets and Brown Dwarfs on Stellar Rotation and Mass-Loss  

E-print Network

We examine the effects of the engulfment of planets by giant stars on the evolution of late-type stars. We show that the rate at which dynamo-generated magnetic energy is being released exceeds 10% of the wind kinetic energy when the orbital angular momentum of the engulfed planet is more than ten times the angular momentum of the star as it leaves the main sequence. A significant enhancement in the mass-loss rate may be expected in this case, due to the formation of cool magnetic spots. We use the existing sample of extrasolar planets to estimate that at least 3.5% of the evolved solar-type stars will be significantly affected by the presence of planetary companions.

Mario Livio; Noam Soker

2002-04-26

354

Extrasolar planet taxonomy: a new statistical approach  

E-print Network

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.

Simone Marchi

2007-05-07

355

On the Minimum Core Mass for Giant Planet Formation at Wide Separations  

NASA Astrophysics Data System (ADS)

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 ?. 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 ? at 5 AU to ~3.5 M ? 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.

Piso, Ana-Maria A.; Youdin, Andrew N.

2014-05-01

356

The Fate of Scattered Planets  

E-print Network

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 primor...

Bromley, Benjamin C

2014-01-01

357

Cassini's Farewell to Jupiter  

NASA Technical Reports Server (NTRS)

On January 15, 2001, 17 days after it passed its closest approach to Jupiter, NASA's Cassini spacecraft looked back to see the giant planet as a thinning crescent.

This image is a color mosaic from that day, shot from a distance of 18.3 million kilometers (11.4 million miles). The smallest visible features are roughly 110 kilometers (70 miles) across. The solar phase angle, the angle from the spacecraft to the planet to the Sun, is 120 degrees.

A crescent Io, innermost of Jupiter's four large moons, appears to the left of Jupiter.

Cassini collected its last Jupiter images on March 22, 2001, as the spacecraft continued the final leg of its journey to a July 1, 2004, appointment with Saturn.

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, Calif., manages Cassini for NASA's Office of Space Science, Washington, D.C.

2001-01-01

358

Elliptical instability in hot Jupiter systems  

NASA Astrophysics Data System (ADS)

Several studies have already considered the influence of tides on the evolution of systems composed of a star and a close-in companion to tentatively explain different observations such as the spin-up of some stars with hot Jupiters, the radius anomaly of short orbital period planets and the synchronization or quasi-synchronization of the stellar spin in some extreme cases. However, the nature of the mechanism responsible for the tidal dissipation in such systems remains uncertain. In this paper, we claim that the so-called elliptical instability may play a major role in these systems, explaining some systematic features present in the observations. This hydrodynamic instability, arising in rotating flows with elliptical streamlines, is suspected to be present in both planet and star of such systems, which are elliptically deformed by tides. The presence and the influence of the elliptical instability in gaseous bodies, such as stars or hot Jupiters, are most of the time neglected. In this paper, using numerical simulations and theoretical arguments, we consider several features associated to the elliptical instability in hot-Jupiter systems. In particular, the use of ad hoc boundary conditions makes it possible to estimate the amplitude of the elliptical instability in gaseous bodies. We also consider the influence of compressibility on the elliptical instability, and compare the results to the incompressible case. We demonstrate the ability for the elliptical instability to grow in the presence of differential rotation, with a possible synchronized latitude, provided that the tidal deformation and/or the rotation rate of the fluid are large enough. Moreover, the amplitude of the instability for a centrally-condensed mass of fluid is of the same order of magnitude as for an incompressible fluid for a given distance to the threshold of the instability. Finally, we show that the assumption of the elliptical instability being the main tidal dissipation process in eccentric inflated hot Jupiters and misaligned stars is consistent with current data.

Cébron, David; Bars, Michael Le; Gal, Patrice Le; Moutou, Claire; Leconte, Jeremy; Sauret, Alban

2013-11-01

359

Photometric Follow-up Observations of the Transiting Neptune-Mass Planet GJ 436b  

E-print Network

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}.

Avi Shporer; Tsevi Mazeh; Frederic Pont; Joshua N. Winn; Matthew J. Holman; David W. Latham; Gilbert A. Esquerdo

2008-05-26

360

Photometric Follow-Up Observations of the Transiting Neptune-Mass Planet GJ 436b  

NASA Astrophysics Data System (ADS)

This paper presents multiband photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of five new ground-based transit light curves obtained in 2007 May. Together with one already published light curve, we have at hand a total of six light curves, spanning 29 days. The analysis of the data yields an orbital period P = 2.64386 ± 0.00003 days, midtransit time Tc [HJD] = 2454235.8355 ± 0.0001, planet mass Mp = 23.1 ± 0.9 M ? = 0.073 ± 0.003 M Jup, planet radius Rp = 4.2 ± 0.2 R ? = 0.37 ± 0.01 R Jup, and stellar radius Rs = 0.45 ± 0.02 R sun. Our typical precision for the midtransit timing for each transit is about 30 s. 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 yr-1.

Shporer, Avi; Mazeh, Tsevi; Pont, Frederic; Winn, Joshua N.; Holman, Matthew J.; Latham, David W.; Esquerdo, Gilbert A.

2009-04-01

361

A FRAMEWORK FOR CHARACTERIZING THE ATMOSPHERES OF LOW-MASS LOW-DENSITY TRANSITING PLANETS  

SciTech Connect

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.

Fortney, Jonathan J.; Nettelmann, Nadine [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Mordasini, Christoph [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Kempton, Eliza M.-R. [Department of Physics, Grinnell College, Grinnell, IA (United States); Greene, Thomas P.; Zahnle, Kevin, E-mail: jfortney@ucolick.org [Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA (United States)

2013-09-20

362

A Framework for Characterizing the Atmospheres of Low-mass Low-density Transiting Planets  

NASA Astrophysics Data System (ADS)

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 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 env. However, values of Z 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 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.

Fortney, Jonathan J.; Mordasini, Christoph; Nettelmann, Nadine; Kempton, Eliza M.-R.; Greene, Thomas P.; Zahnle, Kevin

2013-09-01

363

Post-RGB Stars With Planets And Mass Loss On The RGB.  

NASA Astrophysics Data System (ADS)

Recent observations of mass loss from a fraction of the stars along the RGB in 47 Tuc are at odds with our understanding of single-star mechanisms for mass loss as these kick in only at or above the tip of the RGB. The observations are well fitted by mass loss rates matched to the evolutionary time scale for the stars (dlnM/dt ? dlnR/dt), suggesting a negative-feedback mass loss mechanism depending on the red giant radius. One possibility for such a mechanism is the effect of a jovian-mass planet orbiting near the surface of the red giant; if this drives mass loss then negative feedback is likely for sufficiently large planetary compations. The positive feedback maintains a favorable ratio of the orbital size to the stellar radius, allowing the orbit to expand as the radius expands. A prediction of this explanation for red giant mass loss is that there will be a pronounced overabundance of jovian-mass planets near 1AU around post-RGB stars. This work is supported by the National Science Foundation grant NSF-AST 0708143 to LAW.

Willson, Lee Anne M.; Struck, C.; Wang, Q.; Marasinghe, K.

2009-01-01

364

Rapid heating of the atmosphere of an extrasolar planet.  

PubMed

Near-infrared observations of more than a dozen 'hot-Jupiter' extrasolar planets have now been reported. These planets display a wide diversity of properties, yet all are believed to have had their spin periods tidally spin-synchronized with their orbital periods, resulting in permanent star-facing hemispheres and surface flow patterns that are most likely in equilibrium. Planets in significantly eccentric orbits can enable direct measurements of global heating that are largely independent of the details of the hydrodynamic flow. Here we report 8-microm photometric observations of the planet HD 80606b during a 30-hour interval bracketing the periastron passage of its extremely eccentric 111.4-day orbit. As the planet received its strongest irradiation (828 times larger than the flux received at apastron) its maximum 8-microm brightness temperature increased from approximately 800 K to approximately 1,500 K over a six-hour period. We also detected a secondary eclipse for the planet, which implies an orbital inclination of i approximately 90 degrees , fixes the planetary mass at four times the mass of Jupiter, and constrains the planet's tidal luminosity. Our measurement of the global heating rate indicates that the radiative time constant at the planet's 8-microm photosphere is approximately 4.5 h, in comparison with 3-5 days in Earth's stratosphere. PMID:19177124

Laughlin, Gregory; Deming, Drake; Langton, Jonathan; Kasen, Daniel; Vogt, Steve; Butler, Paul; Rivera, Eugenio; Meschiari, Stefano

2009-01-29

365

KEPLER PLANETS: A TALE OF EVAPORATION  

SciTech Connect

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.

Owen, James E. [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Wu, Yanqin, E-mail: jowen@cita.utoronto.ca, E-mail: wu@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

2013-10-01

366

Kepler Planets: A Tale of Evaporation  

NASA Astrophysics Data System (ADS)

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.

Owen, James E.; Wu, Yanqin

2013-10-01

367

DID FOMALHAUT, HR 8799, AND HL TAURI FORM PLANETS VIA THE GRAVITATIONAL INSTABILITY? PLACING LIMITS ON THE REQUIRED DISK MASSES  

SciTech Connect

Disk fragmentation resulting from the gravitational instability has been proposed as an efficient mechanism for forming giant planets. We use the planet Fomalhaut b, the triple-planetary system HR 8799, and the potential protoplanet associated with HL Tau to test the viability of this mechanism. We choose the above systems since they harbor planets with masses and orbital characteristics favored by the fragmentation mechanism. We do not claim that these planets must have formed as the result of fragmentation, rather the reverse: if planets can form from disk fragmentation, then these systems are consistent with what we should expect to see. We use the orbital characteristics of these recently discovered planets, along with a new technique to more accurately determine the disk cooling times, to place both lower and upper limits on the disk surface density-and thus mass-required to form these objects by disk fragmentation. Our cooling times are over an order of magnitude shorter than those of Rafikov, which makes disk fragmentation more feasible for these objects. We find that the required mass interior to the planet's orbital radius is {approx}0.1 M{sub sun} for Fomalhaut b, the protoplanet orbiting HL Tau, and the outermost planet of HR 8799. The two inner planets of HR 8799 probably could not have formed in situ by disk fragmentation.

Nero, D.; Bjorkman, J. E. [Ritter Observatory, MS 113, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390 (United States)], E-mail: dnero@physics.utoledo.edu

2009-09-10

368

A nebula of gases from Io surrounding Jupiter.  

PubMed

Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii. PMID:11875559

Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

2002-02-28

369

Mr. Mills Reports on Jupiter Flyby.  

National Technical Information Service (NTIS)

Describes how during an odyssey that took the U.S. spacecraft voyager 1 past the giant planet Jupiter in the spring of 1979, extraordinary and unexpected discoveries were made. Shows beautiful color and black and white images of Jupiter and its moons. Mr....

1994-01-01

370

Microlens Masses from Astrometry and Parallax in Space-based Surveys: From Planets to Black Holes  

NASA Astrophysics Data System (ADS)

We show that space-based microlensing experiments can recover lens masses and distances for a large fraction of all events (those with individual photometric errors <~ 0.01 mag) using a combination of one-dimensional microlens parallaxes and astrometric microlensing. This will provide a powerful probe of the mass distributions of planets, black holes, and neutron stars, the distribution of planets as a function of Galactic environment, and the velocity distributions of black holes and neutron stars. While systematics are in principle a significant concern, we show that it is possible to vet against all systematics (known and unknown) using single-epoch precursor observations with the Hubble Space Telescope roughly 10 years before the space mission.

Gould, Andrew; Yee, Jennifer C.

2014-03-01

371

Planets Rapidly Create Holes in Young Circumstellar Discs  

E-print Network

Recent spectral observations by the Spitzer Space Telescope (SST) reveal that some discs around young ($\\sim {\\rm few} \\times 10^6$ yr old) stars have remarkably sharp transitions to a low density inner region in which much of the material has been cleared away. It has been recognized that the most plausible mechanism for the sharp transition at a specific radius is the gravitational influence of a massive planet. This raises the question of whether the planet can also account for the hole extending all the way to the star. Using high resolution numerical simulations, we show that Jupiter-mass planets drive spiral waves which create holes on time scales $\\sim 10$ times shorter than viscous or planet migration times. We find that the theory of spiral-wave driven accretion in viscous flows by Takeuchi et al. (1996) can be used to provide a consistent interpretation of the simulations. In addition, although the hole surface densities are low, they are finite, allowing mass accretion toward the star. Our results therefore imply that massive planets can form extended, sharply bounded spectral holes which can still accommodate substantial mass accretion rates. The results also imply that holes are more likely than gaps for Jupiter mass planets around solar mass stars.

P. Varniere; E. G. Blackman; A. Frank; A. Quillen

2005-10-08

372

The accretion of brown dwarfs and planets by giant stars - II. Solar-mass stars on the red giant branch  

Microsoft Academic Search

This paper extends our previous study of planet\\/brown dwarf accretion by giant stars to solar-mass stars located on the red giant branch. The model assumes that the planet is dissipated at the bottom of the convective envelope of the giant star. The evolution of the giant is then followed in detail. We analyse the effects of different accretion rates and

Lionel Siess; Mario Livio

1999-01-01

373

Kepler-424 b: A "Lonely" Hot Jupiter that Found a Companion  

NASA Astrophysics Data System (ADS)

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.

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

374

DENSITY WAVES EXCITED BY LOW-MASS PLANETS IN PROTOPLANETARY DISKS. I. LINEAR REGIME  

SciTech Connect

Density waves excited by planets embedded in protoplanetary disks play a central role in planetary migration and gap opening processes. We carry out two-dimensional shearing sheet simulations to study the linear regime of wave evolution with the grid-based code Athena and provide detailed comparisons with theoretical predictions. Low-mass planets (down to {approx}0.03 M{sub Circled-Plus} at 1 AU) and high spatial resolution (256 grid points per scale height) are chosen to mitigate the effects of wave nonlinearity. To complement the existing numerical studies, we focus on the primary physical variables such as the spatial profile of the wave, torque density, and the angular momentum flux carried by the wave, instead of secondary quantities such as the planetary migration rate. Our results show percent level agreement with theory in both physical and Fourier spaces. New phenomena such as the change of the toque density sign far from the planet are discovered and discussed. Also, we explore the effect of the numerical algorithms and find that a high order of accuracy, high resolution, and an accurate planetary potential are crucial to achieve good agreement with the theory. We find that the use of a too large time step without properly resolving the dynamical timescale around the planet produces incorrect results and may lead to spurious gap opening. Global simulations of planet migration and gap opening violating this requirement may be affected by spurious effects resulting in, e.g., the incorrect planetary migration rate and gap opening mass.

Dong, Ruobing; Stone, James M.; Petrovich, Cristobal; Rafikov, Roman R., E-mail: rdong@astro.princeton.edu, E-mail: rrr@astro.princeton.edu, E-mail: jstone@astro.princeton.edu, E-mail: cpetrovi@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2011-11-01

375

The Spitzer search for the transits of HARPS low-mass planets  

Microsoft Academic Search

Radial velocity, microlensing and transit surveys have revealed the existence of a large population of low-mass planets in our Galaxy, the so-called `Super-Earths' and `Neptunes'. The understanding of these objects would greatly benefit from the detection of a few of them transiting bright nearby stars, making possible their thorough characterization with high signal-to-noise follow-up measurements. Our HARPS Doppler survey has

Michaël Gillon; Brice-Olivier Demory; Drake Deming; Sara Seager; Christophe Lovis

2011-01-01

376

An Equation of State for Low-Mass Stars and Giant Planets  

Microsoft Academic Search

We present new equations of state (EOS) for hydrogen and helium, intended for applications to low-mass stars (M < 1 Msun), brown dwarfs, and giant planets. They cover the range 2.10

D. Saumon; G. Chabrier; H. M. van Horn

1995-01-01

377

Effects of Magnetism on the Atmospheres and Evolution of Hot Jupiters  

NASA Astrophysics Data System (ADS)

Magnetic effects imprint potentially observable features of close-in extrasolar giant planets, or "hot Jupiters," through two mechanisms: the Lorentz force, which modifies atmospheric dynamics, and Ohmic dissipation, which may have a large impact on the structure and evolution of a planet. We present results from a 3D anelastic magnetohydrodynamic (MHD) model, taking into account purely resistive MHD. We demonstrate that magnetic effects may cause a transition from the expected superrotation in purely hydrodynamic models to subrotation (i.e. wind reversal) at high equilibrium temperatures and magnetic field strengths. This reduction of wind speeds correspondingly reduces hot spot displacement, forcing MHD atmospheric hot spots to be found westward of their hydrodynamic counterparts. For the case of HD 209458b, we do not expect that atmospheric Ohmic dissipation has a large enough magnitude to explain its observed radius, even when scaling the dissipated power into the planetary convective zone. However, the efficacy of Ohmic dissipation is expected to be greater for hot Jupiters with a lower mass than HD 209458b, as these planets have less partial degeneracy and larger pressure scale heights. Hence, Ohmic dissipation can likely explain why a subset of transiting hot Jupiters appear inflated, but other mechanisms may be required to explain those with a mass comparable to or greater than 0.7 Jupiter masses.

Komacek, Thaddeus D.; Rogers, Tamara M.; Barman, Travis S.; Showman, Adam P.; Youdin, Andrew N.

2014-11-01

378

The HARPS search for southern extra-solar planets. III. Three Saturn-mass planets around HD 93083, HD 101930 and HD 102117  

E-print Network

We report on the detection of three Saturn-mass planets discovered with the HARPS instrument. HD 93083 shows radial-velocity (RV) variations best explained by the presence of a companion of 0.37 M_Jup orbiting in 143.6 days. HD 101930 b has an orbital period of 70.5 days and a minimum mass of 0.30 M_Jup. For HD 102117, we present the independent detection of a companion with m2sini = 0.14 M_Jup and orbital period P = 20.7 days. This planet was recently detected by Tinney et al. (2004). Activity and bisector indicators exclude any significant RV perturbations of stellar origin, reinforcing the planetary interpretation of the RV variations. The radial-velocity residuals around the Keplerian fits are 2.0, 1.8 and 0.9 m/s respectively, showing the unprecedented RV accuracy achieved with HARPS. A sample of stable stars observed with HARPS is also presented to illustrate the long-term precision of the instrument. All three stars are metal-rich, confirming the now well-established relation between planet occurrence and metallicity. The new planets are all in the Saturn-mass range, orbiting at moderate distance from their parent star, thereby occupying an area of the parameter space which seems difficult to populate according to planet formation theories. A systematic exploration of these regions will provide new constraints on formation scenarios in the near future.

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

2005-03-30

379

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