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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.

Bill Arnett

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

Direct Imaging of Jupiter and Saturn-mass planets in wide orbit around nearby young stars  

NASA Astrophysics Data System (ADS)

The recent discovery of planetary-mass objects on very wide orbits (hundreds of AU and more) around young stars (e.g. Naud et al. 2014) demonstrates that planets can be found even with arcsecond-level resolution imaging. These massive ( 10MJup) companions are likely formed in-situ via hierarchical collapse and it is not yet known whether this mechanism can form lighter objects. However, dynamical modelling of young planetary systems (Veras et al. 2009) and the relatively large fraction of massive planets in eccentric orbits found by radial velocity surveys suggest that a few percent of planetary systems should host planets, comparable in mass to Jupiter and Saturn, on orbits wide enough to be imaged as isolated objects. We propose to obtain deep IRAC observations combined with J-band imaging gathered by our team to search for such planets around all known nearby young stars (< 70 pc, < 120Myr; 172 stellar systems). This survey will be sensitive to planets down to the mass of Jupiter for all systems and down to the mass of Saturn for 80 of them. Planets lighter than 2MJup are much too faint in the near-infrared to be identified from the ground; Spitzer is the only facility where such a survey can be undertaken. This survey is a unique opportunity to bring direct imaging in a new era with the detection of analogs to our own Solar System Giants, is complementary to the work done on the ground with high-contrast imagers such as GPI and Sphere, and is critical to identify new planets that will be optimally characterized with JWST.

Artigau, Etienne; Lafreniere, David; Baron, Frederique; Malo, Lison; Doyon, Rene; Beichman, Charles; Delorme, Philippe; Rameau, Julien; Janson, Markus; Gagne, Jonathan; Naud, Marie-Eve; Albert, Loic

2014-12-01

4

Eccentric Extrasolar Planets: The Jumping Jupiter Model  

Microsoft Academic Search

Most extrasolar planets discovered to date are more massive than Jupiter, in surprisingly small orbits (semimajor axes less than 3 AU). Many of these have significant orbital eccentricities. Such orbits may be the product of dynamical interactions in multiplanet systems. We examine outcomes of such evolution in systems of three Jupiter-mass planets around a solar-mass star by integration of their

F. Marzari; S. J. Weidenschilling

2002-01-01

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

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

7

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.

8

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

9

The planet Jupiter (1970)  

NASA Technical Reports Server (NTRS)

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

Divine, N.

1971-01-01

10

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

11

Kepler-423b: a half-Jupiter mass planet transiting a very old solar-like star  

NASA Astrophysics Data System (ADS)

We report the spectroscopic confirmation of the Kepler object of interest KOI-183.01 (Kepler-423b), 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 light curve of Kepler-423 exhibits quarter-to-quarter systematic variations of the transit depth, with a peak-to-peak amplitude of ~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 Kepler-423 is a G4 dwarf with M? = 0.85 ± 0.04 M?, R? = 0.95 ± 0.04 R?, Teff= 5560 ± 80 K, [M/H] = - 0.10 ± 0.05 dex, and with an age of 11 ± 2 Gyr. The planet Kepler-423b has a mass of Mp= 0.595 ± 0.081MJup and a radius of Rp= 1.192 ± 0.052RJup, yielding a planetary bulk density of ?p = 0.459 ± 0.083 g cm-3. The radius of Kepler-423b is consistent with both theoretical models for irradiated coreless giant planets and expectations based on empirical laws. The inclination of the stellar spin axis suggests that the system is aligned along the line of sight. We detected a tentative secondary eclipse of the planet at a 2? confidence level (?Fec = 14.2 ± 6.6 ppm) and found that the orbit might have asmall non-zero eccentricity of 0.019+0.028-0.014. With a Bond albedo of AB = 0.037 ± 0.019, Kepler-423b is one of the gas-giant planets with the lowest albedo known so far. Based on observations obtained 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, in time allocated by OPTICON and the Spanish Time Allocation Committee (CAT).The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement number RG226604 (OPTICON) and 267251 (AstroFIt).

Gandolfi, D.; Parviainen, H.; Deeg, H. J.; Lanza, A. F.; Fridlund, M.; Prada Moroni, P. G.; 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.

2015-04-01

12

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

13

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

14

Exploring the diversity of Jupiter-class planets.  

PubMed

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

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

2014-04-28

15

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.

16

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

17

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

18

Microlensing Constraints on the Frequency of Jupiter-Mass Companions: Analysis of 5 Years of PLANET Photometry  

NASA Astrophysics Data System (ADS)

We analyze 5 years of PLANET photometry of microlensing events toward the Galactic bulge to search for the short-duration deviations from single-lens light curves that are indicative of the presence of planetary companions to the primary microlenses. Using strict event-selection criteria, we construct a well-defined sample of 43 intensively monitored events. We search for planetary perturbations in these events over a densely sampled region of parameter space spanning two decades in mass ratio and projected separation, but find no viable planetary candidates. By combining the detection efficiencies of the events, we find that, at 95% confidence, less than 25% of our primary lenses have companions with mass ratio q=10-2 and separations in the lensing zone, [0.6-1.6]?E, where ?E is the Einstein ring radius. Using a model of the mass, velocity, and spatial distribution of bulge lenses, we infer that the majority of our lenses are likely M dwarfs in the Galactic bulge. We conclude that less than 33% of M dwarfs in the Galactic bulge have companions with mass mp=MJ between 1.5 and 4 AU, and less than 45% have companions with mp=3MJ between 1 and 7 AU, the first significant limits on planetary companions to M dwarfs. We consider the effects of the finite size of the source stars and changing our detection criterion, but find that these do not alter our conclusions substantially.

Gaudi, B. S.; Albrow, M. D.; An, J.; Beaulieu, J.-P.; Caldwell, J. A. R.; DePoy, D. L.; Dominik, M.; Gould, A.; Greenhill, J.; Hill, K.; Kane, S.; Martin, R.; Menzies, J.; Naber, R. M.; Pel, J.-W.; Pogge, R. W.; Pollard, K. R.; Sackett, P. D.; Sahu, K. C.; Vermaak, P.; Vreeswijk, P. M.; Watson, R.; Williams, A.

2002-02-01

19

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

SciTech Connect

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

Spiegel, David S. [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Madhusudhan, Nikku, E-mail: dave@ias.edu, E-mail: Nikku.Madhusudhan@yale.edu [Department of Physics and Department of Astronomy, Yale University, New Haven, CT 06511 (United States)

2012-09-10

20

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.

21

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

22

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

23

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

24

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

E-print Network

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

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

2007-01-19

25

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.

26

A Moderate Migration Scenario for Jupiter to form the Terrestrial Planets  

NASA Astrophysics Data System (ADS)

The early solar system contained a gas-dominated protoplanetary disk that could cause the migration of the giant planets. This migration can be in the form of a two-stage migration, including an inward and then outward migration. One of the current favored theories, the Grand Tack theory, states that Jupiter migrates in to 1.5 AU, creating a planetesimal disk truncated at 1 AU to then form the terrestrial planets during the subsequent outward migration of Jupiter. There are reasons to believe that such a large movement by Jupiter may be impractical, namely the disk would need to be massive and long-lived. An exploration of migration parameters that involve smaller migration distances and shorter timescales can shed light on whether such extreme displacements are necessary for the formation of the solar system. We examine more moderate migration simulations, where Jupiter starts near the conjectured location of the ice line and migrates a moderate radial distance inward for a variety of distances and times. After the inward migration, Jupiter moves outwards to its final orbital configuration today. We find that the planetesimal disk need not be truncated at 1 AU to form planets with similar characteristics to those in the solar system. We vary the number and mass of planetesimals in the disk to see how this affects the characteristics of the forming terrestrial planets. We find a number of scenarios that provide systems of terrestrial planets similar to those in the solar system. We thus propose an alternative to the Grand Tack theory where Jupiter's migration is less extreme than proposed in the Grand Tack theory.

Todd, Zoe; Sigurdsson, Steinn

2015-01-01

27

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

28

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.

29

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

30

On the formation of terrestrial planets in hot-Jupiter systems  

E-print Network

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

Martyn J. Fogg; Richard P. Nelson

2006-10-11

31

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

32

Diversity of Extrasolar Planets and Diversity of Molecular Cloud Cores. II. Masses of Gas Giant Planets  

NASA Astrophysics Data System (ADS)

In Paper I, we suggested that the diversity of extrasolar planets might originate from the diversity of molecular cloud cores and specifically illustrated the relationship between semi-major axes of planets in a planetary system and the properties of its progenitor cloud core. In this paper, we investigate the dependence of the mass of a giant planet on the progenitor core properties. We give numerical results of planet masses as a function of the core properties by using the core accretion model of planet formation. Comparing with observations, our model could explain the range and the most frequent values of observed masses of gas giant planets. Our calculations could interpret the observed pileup of gas giants at \\gt 1 AU and the distinct deficit of gas giants from ˜0.05 to 1 AU. Our calculations indicate that it is difficult to form gas giant planets outside 20 AU and the intermediate mass planets might be found at ˜15-30 AU as the observing technique advances. We suggest a formation mechanism of super-Jupiters in the framework of the core accretion model of planet formation. A super-Jupiter can form under the condition that a disk is gravitationally unstable (high viscosity) when a protoplanet opens the deep gap. Our calculations infer that the upper limit of super-Jupiter masses, the range of semi-major axes, and the occurrence rate of super-Jupiters increase with the central star mass. We find that gas giant planets should commonly exist around various stellar masses.

Xiao, Lin; Jin, Liping

2015-04-01

33

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

34

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. Also includes numerous pictures and links to additional websites for more information. The site is also available in Spanish.

Russell, Randy

35

THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED  

SciTech Connect

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

Miller, Neil; Fortney, Jonathan J., E-mail: neil@astro.ucsc.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz (United States)

2011-08-01

36

Searching for Earth Mass Planet via Microlensing  

NASA Astrophysics Data System (ADS)

Core accretion models are today the best alternative to explain the formation of planetary systems: accretion of planetesimals leads to the formation of cores, which then start to accrete gas from the primitive nebula (Laughlin G., et al., 2004 ApJ 612, L73). This scenario predicts in the case of M stars a preferred formation of low mass planets (Earth to Neptune) in a few million years and at distances between 1 and 10 AU. More massive planets (Jupiter) formation is hampered by a longer formation time (10 Myr) during which the gas evaporates and is no longer available to be accreted. This is precisely around this type of stars and at these distances from the star that the microlensing technique has its maximum sensitivity. It presents a sounding advantage over competitive techniques (radial velocities or transits) as being the only method sensitive in this range of distances and low masses. The objective of the PLANET collaboration is the discovery of low mass planets (1-15 Earth masses) within 1-5 AU of the most common stars in our Galaxy, the M stars, in order to measure their frequency. To achieve this goal, we use the gravitational microlensing effect by following the light curve of stars at 8 different telescopes belonging to the PLANET/RoboNET collaborations (32 scientists). After only two detections of Jupiter-size companions around M stars, we have detected in 2005 a planet of 5.5 Earth masses only at 2.8 AU of its M star (Beaulieu et al. 2006, Nature), which is the first member of a new family of cold telluric planets. This detection confirms the power of this new method and, given our detection efficiency; it suggests that these new planets may be quite common around M stars. I will discuss the next generation of planet hunting programs from existing ground base projects, very aggressive ground based operation, Antarctica based operation, to space projects. The detection space is ranging from frozen SuperEarth/Earth to Earth in habitable zone.

Beaulieu, Jean-Philippe; Cassan, A.

2007-08-01

37

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

38

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

SciTech Connect

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

Zhang Hui; Zhou Jilin, E-mail: huizhang@nju.edu.c [Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093 (China)

2010-08-10

39

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

E-print Network

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

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

2004-07-29

40

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

SciTech Connect

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

Jin Liping, E-mail: jinlp@jlu.edu.c [College of Physics, Jilin University, Changchun, Jilin 130021 (China)

2010-09-10

41

On the Final Mass of Giant Planets  

NASA Technical Reports Server (NTRS)

In the core accretion model of giant planet formation, when the core reaches critical mass, hydrostatic equilibrium is no longer possible and gas accretion ensues. If the envelope is radiative, the critical core mass is nearly independent of the boundary conditions and is roughly M(sub crit) 10Mass of the Earth (with weak dependence on the rate of planetesimal accretion M(sub core) and the disk opacity k). Given that such a core may form at the present location of Jupiter in a time comparable to its Type I migration time (10(exp 5) - 10(exp 6) years) provided that the nebula was significantly enhanced in solids with respect to the MMSN and stall at this location in a weakly turbulent (alpha approximately less than 10(exp -4) disk, it may be appropriate to assume that such objects inevitably form and drive the evolution of late-phase T Tauri star disks. Here we investigate the final masses of giant planets in disks with one or more than one such cores. Although the presence of several planets would lead to Type II migration (due to the effective viscosity resulting from the planetary tidal torques), we ignore this complication for now and simply assume that each core has stalled at its location in the disk. Once a core has achieved critical mass, its gaseous accretion is governed by the given Kelvin-Helmholtz timescale.

Estrada, P. R.; Mosqueira, I.

2004-01-01

42

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

43

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

E-print Network

compared to Jupiter at 5 AU from the Sun. One hundred and ten extrasolar giant planets (EGP) have been AU from the stars. The close proximity of the EGPs to the stars together with the detection of EGP

Atreya, Sushil

44

The Search For Jupiter: Combing the Kepler Database for Long Period, Jovian Planets  

NASA Astrophysics Data System (ADS)

The number of known exoplanets is increasingly rapidly, with progress accelerated by dedicated missions such as the Kepler Space Telescope. As NASA's statistics of the planetary census improve, we gain a better understanding of our solar system's place in the galaxy. A satisfactory assessment, however, requires the answers to two questions still just beyond our grasp: (1) What is the frequency of rocky planets with orbits similar to Earth's, and (2) How common are Jupiter-mass planets in roughly circular, decade-long orbits? The Kepler team is actively addressing the first question, but the second still requires significant effort. My work focuses on developing an independent data analysis pipeline that statistically analyzes the public Kepler database for single event, long duration transit signatures. I will present an overview of the data reduction process along with preliminary results that include a number of previously unidentified transit events from Quarters 1-13 of the Kepler mission.

Burt, Jennifer; Laughlin, G.

2013-01-01

45

ON THE FUNDAMENTAL MASS-PERIOD FUNCTIONS OF EXTRASOLAR PLANETS  

SciTech Connect

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

Jiang, I.-G. [Department of Physics and Institute of Astronomy, National Tsing Hua University, Hsin-Chu, Taiwan (China); Yeh, L.-C.; Chang, Y.-C. [Department of Applied Mathematics, National Hsinchu University of Education, Hsin-Chu, Taiwan (China); Hung, W.-L. [Graduate Institute of Computer Science, National Hsinchu University of Education, Hsin-Chu, Taiwan (China)

2010-01-01

46

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

47

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

48

Comparison Between Extrasolar Planets and Low-Mass Secondaries  

E-print Network

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

T. Mazeh; S. Zucker

2000-08-04

49

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

NASA Technical Reports Server (NTRS)

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

Kuchner, Marc

2007-01-01

50

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

51

A common mass scaling for satellite systems of gaseous planets.  

PubMed

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

Canup, Robin M; Ward, William R

2006-06-15

52

Towards a deterministic model of planetary formation. III. Mass distribution of short-period planets around stars of various masses  

E-print Network

The origin of a recently discovered close-in Neptune-mass planet around GJ436 poses a challenge to the current theories of planet formation. Based on the sequential accretion hypothesis and the standard theory of gap formation and orbital migration, we show that around M dwarf stars, close-in Neptune-mass ice-giant planets may be relatively common, while close-in Jupiter-mass gas-giant planets are relatively rare. The mass distribution of close-in planets generally has two peaks at about Neptune mass and Jupiter mass. The lower-mass peak takes the maximum frequency for M dwarfs. Around more massive solar-type stars (G dwarfs), the higher-mass peak is much more pronounced. These are because planets tend to undergo type II migration after fully accreting gas around G dwarfs while they tend to migrate faster than gas accretion around M stars. Close-in Neptune-mass planets may also exist around G dwarfs, though they tend to be mostly composed of silicates and iron cores and their frequency is expected to be much smaller than that of Neptune-mass planets around M dwarfs and that of gas giants around G dwarfs. We also show that the conditions for planets' migration due to their tidal interaction with the disk and the stellar-mass dependence in the disk-mass distribution can be calibrated by the mass distribution of short-period planets around host stars with various masses.

S. Ida; D. N. C. Lin

2005-02-28

53

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

54

The CORALIE survey for southern extra-solar planets. X. A Hot Jupiter orbiting HD73256  

E-print Network

Recent radial-velocity measurements obtained with the CORALIE spectrograph on the 1.2-m Euler Swiss telescope at La Silla unveil the presence of a new Jovian-mass Hot Jupiter around HD 73256. The 1.85-M_Jup planet moves on an extremely short-period (P=2.5486 d), quasi-circular orbit. The best Keplerian orbital solution is presented together with an unsuccessful photometric planetary-transit search performed with the SAT Danish telescope at La Silla. Over the time span of the observations, the photometric follow-up of the candidate has nevertheless revealed a P=14-d photometric periodicity corresponding to the rotational period of the star. This variation as well as the radial-velocity jitter around the Keplerian solution are shown to be related to the fair activity level known for HD 73256.

S. Udry; M. Mayor; J. V. Clausen; L. M. Freyhammer; B. E. Helt; C. Lovis; D. Naef; E. H. Olsen; F. Pepe; D. Queloz; N. C. Santos

2003-06-03

55

Composition and origin of the atmosphere of Jupiter - an update, and implications for the extrasolar giant planets  

NASA Astrophysics Data System (ADS)

New developments have led to this update of the composition and origin of Jupiter's atmosphere that were originally discussed in our Planet. Space Sci. 47 (1999) 1243 paper. Since Jupiter can provide important insight into the atmospheres of extrasolar giant planets (EGP), we also discuss here the possible implications of the first detection of an atmosphere on an EGP. The ammonia mixing ratio on Jupiter has now been determined directly from the Galileo probe mass spectrometer (GPMS) data, and its value relative to H2 (7.1±3.2)×10 -4 in the 9- 12 bar region, is found to be similar to the previously reported result inferred from the radio attenuation technique on Galileo. The Jovian 15N/ 14N ratio is found to be much lower than the terrestrial value at (2.3±0.3)×10 -3. A complete analysis of the various uncertainties in the GPMS data yields an H 2O mixing ratio of 6.0(+3.9,-2.8)×10 -4 at 19 bar in the hotspot, and a trend of increase with depth; all other mixing ratios and error bars remain unchanged. CH 3, previously detected on Saturn and Neptune, has now also been detected in the atmosphere of Jupiter recently by Cassini. Benzene is the heaviest hydrocarbon detected to date in the atmospheres of Jupiter and Saturn. Abundances inferred from Infrared Space Observatory measurements are 9(+4.5,-7.5)×10 14 and 4.7(+2.1,-1.1)×10 13 cm-2 for pressures less than 50 and 10 mbar on Jupiter and Saturn, respectively. Finally, we propose that the recently detected sodium in the atmosphere of the EGP orbiting HD 209458 may have mainly a post-accretionary extraplanetary origin, rather than being primordial.

Atreya, S. K.; Mahaffy, P. R.; Niemann, H. B.; Wong, M. H.; Owen, T. C.

2003-02-01

56

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

57

Composition and origin of the atmosphere of Jupiter—an update, and implications for the extrasolar giant planets  

Microsoft Academic Search

New developments have led to this update of the composition and origin of Jupiter's atmosphere that were originally discussed in our Planet. Space Sci. 47 (1999) 1243 paper. Since Jupiter can provide important insight into the atmospheres of extrasolar giant planets (EGP), we also discuss here the possible implications of the first detection of an atmosphere on an EGP. The

S. k. Atreya; P. R Mahaffy; H. b. Niemann; M. h. Wong; T. c. Owen

2003-01-01

58

Can Planets Survive Stellar Evolution?  

Microsoft Academic Search

We study the survival of gas planets around stars with masses in the range 1-5 Msolar, as these stars evolve off the main sequence. We show that planets with masses smaller than one Jupiter mass do not survive the planetary nebula phase if located initially at orbital distances smaller than 3-5 AU. Planets more massive than two Jupiter masses around

Eva Villaver; Mario Livio

2007-01-01

59

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

60

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

61

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

62

Planets of the solar system. [Jupiter and Venus  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

63

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?

64

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

65

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

66

Minor planets and comets in libration about the 2:1 resonance with Jupiter  

NASA Technical Reports Server (NTRS)

We examine the orbits of minor planets in a search for objects librating about the 2:1 mean-motion resonance with Jupiter. Some 30 candidates are found among the Palomar-Leiden Survey and other unnumbered minor planets. Although almost all the orbits are very uncertain, there does seem to be an indication that librators of low orbital eccentricity do exist, contrary to the hypothesis by Giffen. We also tabulate data describing 12 comets that are temporarily librating about the 2:1 resonance. Finally, we present a discussion of what are apparently 'apocentric' librations. This type of libration, of which we find seven representatives among the numbered minor planets, can occur only for sufficiently small eccentricity. For such bodies, the role of Jupiter's eccentricity is vital; it is associated with a continuing alternation between apocentric libration and an oscillation of the line of apsides.

Franklin, F. A.; Marsden, B. G.; Williams, J. G.; Bardwell, C. M.

1975-01-01

67

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

68

An Astrometrically Measured Mass for Extrasolar Planet  

E-print Network

An Astrometrically Measured Mass for Extrasolar Planet Gliese 876b By Michael McElwain Presented March 14, 2003 #12;Paper details A Mass For the Extrasolar Planet Gliese 876b Determined from Hubble Extrasolar Planets Radial Velocity Measurements Astrometry Photometry Interferometry Gravitational

69

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

E-print Network

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

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

2004-11-09

70

From Very Low Mass Stars to Extrasolar Planets  

NASA Astrophysics Data System (ADS)

We have modeled, using the atmosphere code Phoenix, the photosphere structures and spectral distribution of brown dwarfs and of all known Extrasolar Giant Planets (EGPs) to this day. Since EGPs are often brighter, more massive and larger than telluric planets, they will be more readily detected in the future transit surveys (COROT, KEPLER, SIMS, Eddington), and be the most directly observable using current technology (e.g. by nulling interferometry with the GENIE experiment). In this paper we summarize the spectral properties of EGPs as a function of their orbital distance, phase as viewed from the earth, mass and age, and type of primary star. We establish the most favorable observation conditions (i.e. maximum luminosity contrast of the planet to the primary star). We also explore uncertainties tied to the chemical composition of the atmosphere, and the presence of cloud layers, and study constraining cases such as HD209458b, OGLE-TR56b and Jupiter.

Allard, France; Barman, Travis S.; Paillet, Jimmy; Baraffe, I.; Chabrier, G.; Hauschildt, P. H.

2004-12-01

71

The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultra-Short Periods  

E-print Network

We investigate the possibility of substantial inflation of short-period Jupiter-mass planets, as a result of their internal tidal dissipation associated with the synchronization and circularization of their orbits. We employ the simplest prescription based on an equilibrium model with a constant lag angle for all components of the tide. We show that for young Jupiter-mass planets, with a period less than 3 days, an initial radius about 2 Jupiter radii, and an orbital eccentricity greater than 0.2, the energy dissipated during the circularization of their orbits is sufficiently intense and protracted to inflate their sizes up to their Roche radii.

Pin-Gao Gu; Doug Lin; Peter Bodenheimer

2003-03-17

72

Radial Velocity Detectability of Low Mass Extrasolar Planets in Close Orbits  

E-print Network

Detection of Jupiter mass companions to nearby solar type stars with precise radial velocity measurements is now routine, and Doppler surveys are moving towards lower velocity amplitudes. The detection of several Neptune-mass planets with orbital periods less than a week has been reported. The drive toward the search for close-in Earth-mass planets is on the agenda. Successful detection or meaningful upper limits will place important constraints on the process of planet formation. In this paper, we quantify the statistics of detection of low-mass planets in-close orbits, showing how the detection threshold depends on the number and timing of the observations. In particular, we consider the case of a low-mass planet close to but not on the 2:1 mean motion resonance with a hot jupiter. This scenario is a likely product of the core-accretion hypothesis for planet formation coupled with migration of jupiters in the protoplanetary disk. It is also advantageous for detection because the orbital period is well-constrained. Detection of few Earth mass rocky cores will require ~ 1 m/s velocity precision, and most importantly, a much better understanding of stellar radial velocity jitter.

Raman Narayan; Andrew Cumming; D. N. C. Lin

2004-09-30

73

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

NASA Astrophysics Data System (ADS)

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 and Probe, ISO and Voyager, complemented by ground-based observations (Atreya et al., PSS 47, 1243, 1999; Encrenaz et al., PSS, 47, 1223, 1999; Atreya et al., PSS, 2002, in press). Although the atmosphere is made up of mostly H and He, trace amounts of CH4 and its products, H O, NH 3, H2S,22 heavy noble gases (Ne, Ar, Kr, Xe), and disequilibrium species (PH3, CO, CO2, GeH4, AsH3), are also detected. From measurements of the trace constituents in Jupiter's upper and the deep well-mixed troposphere by the Galileo Probe, it has been possible to determine the "bulk" abundance of the heavy elements, which is key to understanding the origin and evolution of the planet's atmosphere. C, N, S, Ar, Kr and Xe are all found to be enriched by a factor of 2-4 relative to their solar ratios to H. This unexpected finding led Owen et al. (Nature, 402, 269, 1999) to suggest that the icy planetesimals that formed Jupiter must have had a low temperature (=30 K) origin in order for them to trap the volatiles containing the heavy elements. An alternate hypothesis - according to which the volatiles were trapped in clathrate hydrates instead (Gautier et al., Ap. J., 550, L227, 2001) - overestimates Jupiter's sulfur abundance, and it too requires a remarkably low temperature of =38 K for argon clathration (Gautier et al., Ap. J., 559, L183, 2001) Could the known composition of Jupiter help in understanding the atmospheres of the EGP's? So far, only sodium has been detected in the atmosphere of an EGP that orbits a sun-like star, HD 209458, at 0.0468 AU (Charbonneau et al., Ap. J., 568, 377, 2002). However, sodium has not been detected in the atmosphere of Jupit er. If the above EGP formed like Jupiter, and so started out its life colder (than its current equilibrium temperature of as much as 1400 K), the observed sodium in its atmosphere may be of an extraplanetary origin, rather being primordial (Atreya et al., PSS, 2002, in press).

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

74

Simulating Photoevaporative Mass Loss from Hot Jupiters in 3D  

NASA Astrophysics Data System (ADS)

Escaping planetary winds have been observed with UV transmission spectra from several transiting hot Jupiters. To find other observational signatures of these winds, we are developing a global model of atmospheric escape from hot Jupiters. Our goal is to model the full, asymmetric structure of the wind, which is driven by photoionizing stellar flux and shaped by stellar winds and orbital motion. This poster presents the current status of our model, which simultaneously includes photoionization heating and is done in three dimensions, unlike previous models. Using the Athena code for hydrodynamics, we model the planet as a static potential with a hydrostatic atmosphere, at the center of a three-dimensional Cartesian grid. We self-consistently treat the planetary wind's production by introducing a planar source of stellar UV flux and evolving it with ionizing radiative transfer coupled to the hydrodynamics. We have implemented our ionization algorithm to include Static Mesh Refinement (SMR) and parallelization with MPI, to resolve the planet's exosphere. Tests of the evolution of a planar ionization front in our code match analytic expectations for the propagation rate of a D-type ionization front. Further code development is in progress, and we plan to include the major contributions to the outflow's asymmetry - the stellar wind, which can confine the planetary wind structure, and the Coriolis force, which captures the planet's orbital motion. Since Athena and our radiative transfer code are compatible with MHD, extensions to the model can further include the planet's magnetic field.

Tripathi, Anjali; Kratter, Kaitlin; Krumholz, Mark; Murray-Clay, Ruth

2013-07-01

75

Search for X rays from the planet Jupiter.  

NASA Technical Reports Server (NTRS)

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

Hurley, K. C.

1972-01-01

76

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

77

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.

78

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

79

Planet Hunters. V. A Confirmed Jupiter-size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data  

NASA Astrophysics Data System (ADS)

We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R PL = 10.12 ± 0.56 R ?) 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.; Barclay, Thomas; Boyajian, Tabetha S.; Crepp, Justin R.; Schwamb, Megan E.; Lintott, Chris; Jek, Kian J.; Smith, Arfon M.; Parrish, Michael; Schawinski, Kevin; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M.; Lynn, Stuart; Simpson, Robert; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Chopin, Mike; Herszkowicz, Rafal

2013-10-01

80

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

81

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

82

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

SciTech Connect

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

Li Shulin [Department of Astronomy, Kavli Institute of Astronomy and Astrophysics, Peking University, Beijing (China); Agnor, C.B. [Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London (United Kingdom); Lin, D. N. C. [Department of Astronomy and Astrophysics, University of California Santa Cruz (United States)

2010-09-10

83

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

84

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

E-print Network

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

Noam Soker

2000-06-26

85

Magnetically controlled mass loss from extrasolar planets in close orbits  

E-print Network

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 $B_P\\gtrsim 0.3$ gauss and fluxes $F_{UV}\\sim10^{6}$ 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 s...

Owen, James E

2014-01-01

86

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

87

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 reg...

Payne, Matthew J

2007-01-01

88

The mass disruption of Jupiter Family comets  

NASA Astrophysics Data System (ADS)

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

Belton, Michael J. S.

2015-01-01

89

THE MASS DISTRIBUTION OF SUBGIANT PLANET HOSTS  

SciTech Connect

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

Lloyd, James P. [Department of Astronomy, Cornell University, Ithaca, NY (United States)

2013-09-01

90

The Mass Distribution of Subgiant Planet Hosts  

NASA Astrophysics Data System (ADS)

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

Lloyd, James P.

2013-09-01

91

Heavyweight Champion: Jupiter  

NSDL National Science Digital Library

In this activity, learners confront their perceptions of gravity in the solar system. Learners weigh themselves on scales modified to represent their weights on other worlds to explore the concept of gravity and its relationship to weight. They consider how their weights would be the highest of all the planets while standing on Jupiter, but their mass remains the same no matter where in the solar system they are! Learners compare the features of different planets to determine which characteristics cause a planet to have more or less gravity. This activity is part of a sequence of activities focused on Jupiter's immense size.

2014-07-11

92

PREDICTING PLANETS IN KNOWN EXTRASOLAR PLANETARY SYSTEMS. II. TESTING FOR SATURN MASS PLANETS  

E-print Network

PREDICTING PLANETS IN KNOWN EXTRASOLAR PLANETARY SYSTEMS. II. TESTING FOR SATURN MASS PLANETS Sean known extrasolar planets, including 10 systems containing two or more planets. These planets are known we test for the presence of unseen massive planets in four known extrasolar planetary systems: HD

Barnes, Rory

93

A search for Mars-mass extrasolar planets with Spitzer  

Microsoft Academic Search

We propose to make 6 observations of the transits of the hot Jupiter planet HD 189733b and six observations of its secondary eclipse in order to detect variations of the times of transit\\/eclipse due to secondary planets in the system, if present. Spitzer is the best telescope for transit timing of this system, allowing nearly an order of magnitude better

Eric Agol; David Charbonneau; Nicolas Cowan; Drake Deming; Heather Knutson; Jason Steffen

2007-01-01

94

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

95

Probing clouds in planets with a simple radiative transfer model: the Jupiter case  

NASA Astrophysics Data System (ADS)

Remote sensing of planets evokes using expensive on-orbit satellites and gathering complex data from space. However, the basic properties of clouds in planetary atmospheres can be successfully estimated with small telescopes even from an urban environment using currently available and affordable technology. This makes the process accessible for undergraduate students while preserving most of the physics and mathematics involved. This paper presents the methodology for carrying out a photometric study of planetary atmospheres, focused on the planet Jupiter. The method introduces the basics of radiative transfer in planetary atmospheres, some notions on inverse problem theory and the fundamentals of planetary photometry. As will be shown, the procedure allows the student to derive the spectral reflectivity and top altitude of clouds from observations at different wavelengths by applying a simple but enlightening ‘reflective layer model’. In this way, the planet's atmospheric structure is estimated by students as an inverse problem from the observed photometry. Web resources are also provided to help those unable to obtain telescopic observations of the planets.

Mendikoa, Iñigo; Pérez-Hoyos, Santiago; Sánchez-Lavega, Agustín

2012-11-01

96

Young, Jupiter-Mass Objects in Ophiuchus  

NASA Astrophysics Data System (ADS)

We have used 3.5 to 8 ?m data from the Cores to Disks (c2d) Legacy survey and our own deep IJHKs images of a 0.5 square degree portion of the c2d fields in Ophiuchus to produce a sample of candidate young objects with probable masses between 1 and 10 MJupiter. The availability of photometry over whole range where these objects emit allows us to discriminate between young, extremely low-mass candidates and more massive foreground and background objects and means our survey will have fewer false positives than existing near-IR surveys. The sensitive inventory of a star forming cloud from the red to the mid-IR will allow us to constrain the IMF for these non-clustered star formation regions to well below the deuterium burning limit. For stars with fluxes in the broad gap between the 2MASS limits and our limits, our data will provide information about the photospheres. We will use the Spitzer results in combination with current disk models to learn about the presence and nature of circumstellar disks around young brown dwarfs.

Allers, K. N.; Jaffe, D. T.; van der Bliek, N. S.; Allard, F.; Baraffe, I.

2006-12-01

97

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

NASA Astrophysics Data System (ADS)

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 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 h 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-1. These measurements lead to a well defined orbit and consequently to the precise orbital parameters determination of the extra-solar planet HD 330075 b. Based on observations made with the HARPS instrument on the ESO 3.6 m telescope at the La Silla Observatory under programme ID 72.C-0488

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

2004-08-01

98

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

99

Viscoelastic tidal dissipation in giant planets and formation of hot Jupiters through high-eccentricity migration  

NASA Astrophysics Data System (ADS)

We study the possibility of tidal dissipation in the solid cores of giant planets and its implication for the formation of hot Jupiters through high-eccentricity migration. We present a general framework by which the tidal evolution of planetary systems can be computed for any form of tidal dissipation, characterized by the imaginary part of the complex tidal Love number, Im[{tilde{k}}_2(? )], as a function of the forcing frequency ?. Using the simplest viscoelastic dissipation model (the Maxwell model) for the rocky core and including the effect of a non-dissipative fluid envelope, we show that with reasonable (but uncertain) physical parameters for the core (size, viscosity and shear modulus), tidal dissipation in the core can accommodate the tidal-Q constraint of the Solar system gas giants and at the same time allows exoplanetary hot Jupiters to form via tidal circularization in the high-e migration scenario. By contrast, the often-used weak friction theory of equilibrium tide would lead to a discrepancy between the Solar system constraint and the amount of dissipation necessary for high-e migration. We also show that tidal heating in the rocky core can lead to modest radius inflation of the planets, particularly when the planets are in the high-eccentricity phase (e ˜ 0.6) during their high-e migration. Finally, as an interesting by-product of our study, we note that for a generic tidal response function Im[{tilde{k}}_2(? )], it is possible that spin equilibrium (zero torque) can be achieved for multiple spin frequencies (at a given e), and the actual pseudo-synchronized spin rate depends on the evolutionary history of the system.

Storch, Natalia I.; Lai, Dong

2014-02-01

100

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

101

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

NASA Astrophysics Data System (ADS)

Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should be detectable through Ly? transit spectroscopy according to predictions. We use X-ray observations with Chandra and XMM-Newton of seven of these targets to derive the high-energy irradiation level of the planetary atmospheres and the resulting mass loss rates. We further derive improved Ly? luminosity estimates for the host stars including interstellar absorption. According to our estimates WASP-80 b, WASP-77 b, and WASP-43 b experience the strongest mass loss rates, exceeding the mass loss rate of HD 209458 b, where an expanded atmosphere has been confirmed. Furthermore, seven out of nine targets might be amenable to Ly? transit spectroscopy. Finally, we check the possibility of angular momentum transfer from the hot Jupiters to the host stars in the three binary systems among our sample, but find only weak indications for increased stellar rotation periods of WASP-77 and HAT-P-20.

Salz, M.; Schneider, P. C.; Czesla, S.; Schmitt, J. H. M. M.

2015-04-01

102

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

SciTech Connect

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

Mousis, Olivier; Lunine, Jonathan I. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ (United States); Marboeuf, Ulysse; Alibert, Yann [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Fletcher, Leigh N.; Orton, Glenn S. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Pauzat, Francoise; Ellinger, Yves [Laboratoire de Chimie Theorique (LCT/LETMEX), CNRS-UMR 7616, Universite Pierre et Marie Curie, 4, Place Jussieu, 75252, Paris cedex 05 (France)], E-mail: mousis@lpl.arizona.edu

2009-05-10

103

Determination of the Minimum Masses of Heavy Elements in the Envelopes of Jupiter and Saturn  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

104

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

SciTech Connect

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

Agnor, Craig B. [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London (United Kingdom); Lin, D. N. C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States)

2012-02-01

105

Solar wind flow about the outer planets - Gas dynamic modeling of the Jupiter and Saturn bow shocks  

Microsoft Academic Search

It has been found that the solar wind is diverted about planets through the formation of bow shocks which heat and deflect the flow. These observations are based on missions concerned with Mercury, Venus, earth, and Mars during the 1960s and 1970s. The present study has the objective to extend to Jupiter and Saturn certain aspects of the analyses which

J. A. Slavin; E. J. Smith; J. R. Spreiter; S. S. Stahara

1985-01-01

106

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

107

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

108

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

109

Viscoelastic Tidal Dissipation in Giant Planets and Formation of Hot Jupiters Through High-Eccentricity Migration  

E-print Network

We study the possibility of tidal dissipation in the solid cores of giant planets and its implication for the formation of hot Jupiters through high-eccentricity migration. We present a general framework by which the tidal evolution of planetary systems can be computed for any form of tidal dissipation, characterized by the imaginary part of the complex tidal Love number, ${\\rm Im}[{\\tilde k}_2(\\omega)]$, as a function of the forcing frequency $\\omega$. Using the simplest viscoelastic dissipation model (the Maxwell model) for the rocky core and including the effect of a nondissipative fluid envelope, we show that with reasonable (but uncertain) physical parameters for the core (size, viscosity and shear modulus), tidal dissipation in the core can accommodate the tidal-Q constraint of the Solar System gas giants and at the same time allows exoplanetary hot Jupiters to form via tidal circularization in the high-e migration scenario. By contrast, the often-used weak friction theory of equilibrium tide would lead...

Storch, Natalia I

2013-01-01

110

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

111

Effects of mass loss for highly-irradiated giant planets  

NASA Astrophysics Data System (ADS)

We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres differ by two orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Baraffe et al. [Baraffe, I., Selsis, F., Chabrier, G., Barman, T.S., Allard, F., Hauschildt, P.H., Lammer, H., 2004. Astron. Astrophys. 419, L13-L16] predict the highest rate, based on the theory of Lammer et al. [Lammer, H., Selsis, F., Ribas, I., Guinan, E.F., Bauer, S.J., Weiss, W.W., 2003. Astrophys. J. 598, L121-L124]. Scaling the theory of Watson et al. [Watson, A.J., Donahue, T.M., Walker, J.C.G., 1981. Icarus 48, 150-166] to parameters for a highly-irradiated exoplanet, we find an escape rate ˜10 lower than Baraffe's. With the scaled Watson theory we find modest mass loss, occurring early in the history of a hot EGP. In this theory, mass loss including the effect of Roche-lobe overflow becomes significant primarily for masses below a Saturn mass, for semimajor axes ?0.023 AU. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present.

Hubbard, W. B.; Hattori, M. F.; Burrows, A.; Hubeny, I.; Sudarsky, D.

2007-04-01

112

Mass Loss for Highly-Irradiated Giant Planets  

NASA Astrophysics Data System (ADS)

We present calculations for the surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Available theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres range over four orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Yelle (Icarus 170, 167-179, 2004) predicts the lowest escape rate. Baraffe et al. (A&A 419, L13-L16, 2004) predict the highest rate, based on the theory of Lammer et al. (ApJ 598, L121-L124, 2003). Scaling the theory of Watson et al. (Icarus 48, 150-166, 1981) to parameters for a highly-irradiated exoplanet, we find an intermediate escape rate, ˜ 102 higher than Yelle's but ˜ 102 lower than Baraffe's. With the scaled Watson theory and the scaled Yelle theory we find modest mass loss, occurring early in the history of a hot EGP. Particularly for the Yelle theory, the effect of tidal truncation sets the minimum mass limit, well below a Saturn mass for the distances investigated. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present. Supported by NASA Grant NAG5-13775 (PGG) and NASA Grant NNG04GL22G (ATP).

Hubbard, W. B.; Burrows, A.; Hubeny, I.; Sudarsky, D.; Hattori, M. F.

2005-08-01

113

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

114

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

115

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

116

On the Mass-Period Correlation of the Extrasolar Planets  

E-print Network

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

Shay Zucker; Tsevi Mazeh

2002-02-22

117

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

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

118

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

119

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

2008-12-09

120

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

SciTech Connect

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

Sumi, T.; Abe, F.; Fukui, A., E-mail: sumi@stelab.nagoya-u.ac.j, E-mail: abe@stelab.nagoya-u.ac.j, E-mail: afukui@stelab.nagoya-u.ac.j [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan)

2010-02-20

121

Tidal Barrier and the Asymptotic Mass of Proto Gas-Giant Planets  

E-print Network

Extrasolar planets found with radial velocity surveys have masses ranging from several Earth to several Jupiter masses. While mass accretion onto protoplanetary cores in weak-line T-Tauri disks may eventually be quenched by a global depletion of gas, such a mechanism is unlikely to have stalled the growth of some known planetary systems which contain relatively low-mass and close-in planets along with more massive and longer period companions. Here, we suggest a potential solution for this conundrum. In general, supersonic infall of surrounding gas onto a protoplanet is only possible interior to both of its Bondi and Roche radii. At a critical mass, a protoplanet's Bondi and Roche radii are equal to the disk thickness. Above this mass, the protoplanets' tidal perturbation induces the formation of a gap. Although the disk gas may continue to diffuse into the gap, the azimuthal flux across the protoplanets' Roche lobe is quenched. Using two different schemes, we present the results of numerical simulations and analysis to show that the accretion rate increases rapidly with the ratio of the protoplanet's Roche to Bondi radii or equivalently to the disk thickness. In regions with low geometric aspect ratios, gas accretion is quenched with relatively low protoplanetary masses. This effect is important for determining the gas-giant planets' mass function, the distribution of their masses within multiple planet systems around solar type stars, and for suppressing the emergence of gas-giants around low mass stars.

Ian Dobbs-Dixon; Shu Lin Li; D. N. C. Lin

2007-01-09

122

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

123

Planet Engulfment by ~1.5-3 Solar-Mass Red Giants  

E-print Network

Recent radial-velocity surveys for GK clump giants have revealed that planets also exist around ~1.5-3 Msun stars. However, no planets have been found inside 0.6 AU around clump giants, in contrast to solar-type main-sequence stars, many of which harbor short-period planets such as hot Jupiters. In this study we examine the possibility that planets were engulfed by host stars evolving on the red-giant branch (RGB). We integrate the orbital evolution of planets in the RGB and helium burning (HeB) phases of host stars, including the effects of stellar tide and stellar mass loss. Then we derive the critical semimajor axis (or the survival limit) inside which planets are eventually engulfed by their host stars after tidal decay of their orbits. Especially, we investigate the impact of stellar mass and other stellar parameters on the survival limit in more detail than previous studies. In addition, we make detailed comparison with measured semimajor axes of planets detected so far, which no previous study did. We ...

Kunitomo, M; Sato, B; Katsuta, Y; Ida, S

2011-01-01

124

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

125

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

126

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

127

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

SciTech Connect

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

Zhang Hui; Zhou Jilin, E-mail: huizhang@nju.edu.c [Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093 (China)

2010-05-01

128

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

129

Dunking the Planets  

NSDL National Science Digital Library

In this demonstration, learners compare the relative sizes and masses of scale models of the planets as represented by fruits and other foods. Learners 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 a sequence of activities focused on Jupiter's immense size.

2014-07-11

130

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

131

Jupiter News  

NSDL National Science Digital Library

This newsletter is designed to share NASA mission discoveries about the planet Jupiter which includes information about the 2009 Impact, birth of red spot storms, observed color changes in its atmospheric bands, calculated wind speeds, strong magnetic field-causing spectacular aurora and explanation of Jupiter's Gossamer Ring formation.

132

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

133

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

NASA Technical Reports Server (NTRS)

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

Marley, Mark Scott; Sengupta, Sujan

2012-01-01

134

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

135

Dynamical Stability of Terrestrial Mass Planets in and around the Habitable Zones of Single Planet Systems  

Microsoft Academic Search

We discuss the dynamical stability of hypothetical terrestrial mass planets (1 -10 Earth masses) in the habitable zone (HZ) of systems which have an additional massive planet. We consider arbitrary masses and orbits, which cover the range of observed planetary system architectures. We determine stability through N-body simulations which we compare to the analytic \\

Ravi Kumar Kopparapu; R. Barnes

2010-01-01

136

Dynamical stability of terrestrial mass planets in and around the habitable zones of single planet systems  

Microsoft Academic Search

We discuss the dynamical stability of hypothetical terrestrial mass planets (1 -10 Earth masses) in the habitable zone (HZ) of systems which have an additional massive planet. We consider arbitrary masses and orbits, which cover the range of observed planetary system architectures. We determine stability through N-body simulations which we compare to the analytic \\

R. Kopparapu; R. Barnes

2009-01-01

137

Can Planets survive Stellar Evolution?  

E-print Network

We study the survival of gas planets around stars with masses in the range 1-5 Msun, as these stars evolve off the Main Sequence. We show that planets with masses smaller than one Jupiter mass do not survive the Planetary Nebula phase if located initially at orbital distances smaller than (3-5) AU. Planets more massive than two Jupiter masses around low mass (1 Msun on the Main Sequence) stars survive the Planetary Nebula stage down to orbital distances of 3 AU. As the star evolves through the Planetary Nebula phase, an evaporation outflow will be established at the planet's surface. Evaporating planets may be detected using spectroscopic observations. Planets around white dwarfs with masses M_WD > 0.7 Msun are generally expected to be found at orbital radii r > 15 AU. If planets are found at smaller orbital radii around massive white dwarfs, they had to form as the result of the merger of two white dwarfs.

Eva Villaver; Mario Livio

2007-02-27

138

Voyager 2 Jupiter encounter  

NASA Technical Reports Server (NTRS)

A NASA News Release is presented which contains the following: (1) general release; (2) two views of Voyager 2 flight past Jupiter; (3) Voyager mission summary; (4) Voyager 1 science results; (5) Jupiter science objectives; (6) Jupiter the planet and its satellites; (7) Voyager experiments; (8) planet comparison; (9) a list of Voyager science investigators and (10) the Voyager team.

1979-01-01

139

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

E-print Network

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

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

2007-01-01

140

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

141

An extrasolar planetary system with three Neptune-mass planets  

Microsoft Academic Search

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 2-15days. Here we report a system of three Neptune-mass planets with periods of 8.67,

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

2006-01-01

142

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

143

The mass of dwarf planet Eris.  

PubMed

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

Brown, Michael E; Schaller, Emily L

2007-06-15

144

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

145

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

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

146

The effect of type I migration on the formation of terrestrial planets in hot-Jupiter systems  

E-print Network

Context: Our previous models of a giant planet migrating through an inner protoplanet/planetesimal disk find that the giant shepherds a portion of the material it encounters into interior orbits, whilst scattering the rest into external orbits. Scattering tends to dominate, leaving behind abundant material that can accrete into terrestrial planets. Aims: We add to the possible realism of our model by simulating type I migration forces which cause an inward drift, and strong eccentricity and inclination damping of protoplanetary bodies. This extra dissipation might be expected to enhance shepherding at the expense of scattering, possibly modifying our previous conclusions. Methods: We employ an N-body code that is linked to a viscous gas disk algorithm capable of simulating: gas accretion onto the central star; gap formation in the vicinity of the giant planet; type II migration of the giant planet; type I migration of protoplanets; and the effect of gas drag on planetesimals. We use the code to re-run three scenarios from a previous work where type I migration was not included. Results: The additional dissipation introduced by type I migration enhances the inward shepherding of material but does not severely reduce scattering. We find that > 50% of the solids disk material still survives the migration in scattered exterior orbits: most of it well placed to complete terrestrial planet formation at terrestrial planets can form in the habitable zones of hot-Jupiter systems and hot-Earths and hot-Neptunes may also be present. These systems should be targets of future planet search missions.

Martyn J. Fogg; Richard P. Nelson

2007-07-18

147

Water contents of Earth-mass planets around M dwarfs  

NASA Astrophysics Data System (ADS)

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

Tian, Feng; Ida, Shigeru

2015-03-01

148

Effect of Mass Loss on Statistics of Highly-Irradiated Giant Planets  

NASA Astrophysics Data System (ADS)

We present evolutionary calculations of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using theoretical estimates from energy-limited hydrogen escape. These estimates are taken from Yelle (2004, Icarus 170, 167-179), Watson et al. (1981, Icarus 48, 150-166) and Baraffe et al. (2004, A&A 419, L13-L16), based on the theory by Lammer et al. (2003, ApJ. 598, L121- L124). Escape rates vary over four orders of magnitude with Yelle having the lowest and Baraffe/Lammer having the highest. We fit an initial mass function (IMF) using 169 extrasolar planets and then develop mass functions at different time steps and distances, scaling for the three different mass loss models while holding planetary composition and irradiation constant. The Baraffe model shows the most extreme mass loss, and if it were realistic, observed highly-irradiated EGPs would be remnants of massive bodies of several Jupiter masses, and their mass function would be an increasing function of mass, possibly contrary to observation. The Yelle model shows more tidal truncation effects, with only the smallest masses (less than a Saturn mass) strongly affected by irradiation. The corresponding mass function for highly-irradiated EGPs, in the Yelle model, would resemble the IMF except for EGP masses well below a Saturn mass. Supported by NASA PGG Grant NAG5-13775.

Hattori, Maki F.; Hubbard, W. B.

2006-09-01

149

Hot Jupiters in binary star systems  

E-print Network

Radial velocity surveys find Jupiter mass planets with semi-major axes a less than 0.1 AU around ~1% of solar-type stars; counting planets with $a$ as large as 5 AU, the fraction of stars having planets reaches ~ 10% {Marcy,Butler}. An examination of the distribution of semi-major axes shows that there is a clear excess of planets with orbital periods around 3 or 4 days, corresponding to a~0.03$ AU, with a sharp cutoff at shorter periods (see Figure 1). It is believed that Jupiter mass planets form at large distances from their parent stars; some fraction then migrate in to produce the short period objects. We argue that a significant fraction of the `hot Jupiters' (aJupiters with the peak of the semimajor axis distribution lying around 3 days. For the observed distributions of binary separation, eccentricity and mass ratio, roughly 2.5% of planets with initial semimajor axis a_p ~ 5au will migrate to within 0.1au of their parent star. Kozai migration could account for 10% or more of the observed hot Jupiters.

Yanqin Wu; Norman W. Murray; J. Michael Ramsahai

2007-08-02

150

Parasitic interference in long baseline optical interferometry -Requirements for hot Jupiter-like planet detection  

E-print Network

Parasitic interference in long baseline optical interferometry - Requirements for hot Jupiter of the complex visibility, may be corrupted by parasitic fringes superimposed on the genuine fringe pattern crosstalk between beams. We deduced that the parasitic interference significantly affects

Paris-Sud XI, Université de

151

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

152

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

SciTech Connect

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

Dupuy, Trent J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Liu, Michael C.

2009-10-20

153

Detecting Earth-Mass Planets with Gravitational Microlensing  

E-print Network

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

David P. Bennett; Sun Hong Rhie

1996-03-30

154

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

155

Exotic Earths: forming habitable worlds with giant planet migration.  

PubMed

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

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

2006-09-01

156

Giant Planets Tristan Guillot  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.2 Uranus and Neptune . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 the interior structure and evolution of Jupiter, Saturn, Uranus and Neptune, and extrasolar giant planets, Jupiter, Saturn, Uranus, Neptune, planet formation 1 Introduction In our Solar System, four planets stand

Paris-Sud XI, Université de

157

Mass–radius curve for extrasolar Earth-like planets and ocean planets  

Microsoft Academic Search

By comparison with the Earth-like planets and the large icy satellites of the Solar System, one can model the internal structure of extrasolar planets. The input parameters are the composition of the star (Fe\\/Si and Mg\\/Si), the Mg content of the mantle (Mg#=Mg\\/[Mg+Fe]), the amount of H2O and the total mass of the planet. Equation of State (EoS) of the

C. Sotin; O. Grasset; A. Mocquet

2007-01-01

158

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

NASA Astrophysics Data System (ADS)

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

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

2015-04-01

159

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

SciTech Connect

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

Gaidos, Eric [Department of Geology and Geophysics, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Mann, Andrew W.; Howard, Andrew W., E-mail: gaidos@hawaii.edu [Institute for Astronomy, University of Hawai'i at Manoa, Honolulu, HI 96822 (United States)

2013-07-01

160

A ˜7.5 Earth-Mass Planet Orbiting the Nearby Star, GJ 876  

NASA Astrophysics Data System (ADS)

High precision, high cadence radial velocity monitoring over the past 8 years at the W. M. Keck Observatory reveals evidence for a third planet orbiting the nearby (4.69 pc) dM4 star GJ 876. The residuals of three-body Newtonian fits, which include GJ 876 and Jupiter mass companions b and c, show significant power at a periodicity of 1.9379 days. Self-consistently fitting the radial velocity data with a model that includes an additional body with this period significantly improves the quality of the fit. These four-body (three-planet) Newtonian fits find that the minimum mass of companion ``d'' is m sin {i}=5.89 ± 0.54 M? and that its orbital period is 1.93776 (± 7×10-5) days. Assuming coplanar orbits, an inclination of the GJ 876 planetary system to the plane of the sky of ˜50o gives the best fit. This inclination yields a mass for companion d of m=7.53 ± 0.70 M? , making it by far the lowest mass companion yet found around a main sequence star other than our Sun. Precise photometric observations at Fairborn Observatory confirm low-level brightness variability in GJ 876 and provide the first explicit determination of the star's 96.7-day rotation period. Even higher precision short-term photometric measurements obtained at Las Campanas imply that planet d does not transit GJ 876.

Rivera, E. J.; Lissauer, J. J.; Butler, R. P.; Marcy, G. W.; Vogt, S. S.; Fischer, D. A.; Brown, T. M.; Laughlin, G.; Henry, G. W.

2005-12-01

161

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

162

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

163

High resolution imaging of young M-type stars of the solar neighborhood: Probing the existence of companions down to the mass of Jupiter  

E-print Network

Context. High contrast imaging is a powerful technique to search for gas giant planets and brown dwarfs orbiting at separation larger than several AU. Around solar-type stars, giant planets are expected to form by core accretion or by gravitational instability, but since core accretion is increasingly difficult as the primary star becomes lighter, gravitational instability would be the a probable formation scenario for yet-to-be-found distant giant planets around a low-mass star. A systematic survey for such planets around M dwarfs would therefore provide a direct test of the efficiency of gravitational instability. Aims. We search for gas giant planets orbiting around late-type stars and brown dwarfs of the solar neighborhood. Methods. We obtained deep high resolution images of 16 targets with the adaptive optic system of VLT-NACO in the Lp band, using direct imaging and angular differential imaging. This is currently the largest and deepest survey for Jupiter-mass planets around Mdwarfs. We developed and us...

Delorme, P; Chauvin, G; Bonavita, M; Lacour, S; Bonnefoy, M; Ehrenreich, D; Beust, H

2011-01-01

164

50&100YEARSAGO EXTRASOLAR PLANETS  

E-print Network

the discovery of fluorescent emission from methane in the upper atmosphere of a nearby, Jupiter-mass extrasolar planet6 , HD 189733b (Fig. 1). Fluorescence occurs when an atom or mol- ecule absorbs a photon

Royer, Dana

165

Terrestrial Planet Formation in a Protoplanetary Disk with a Local Mass Depletion: A Successful Scenario for the Formation of Mars  

NASA Astrophysics Data System (ADS)

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

Izidoro, A.; Haghighipour, N.; Winter, O. C.; Tsuchida, M.

2014-02-01

166

On the Mass-Period Correlation of the Extrasolar Planets  

Microsoft Academic Search

We report on a possible correlation between the masses and periods of the extrasolar planets, manifested as a paucity of massive planets with short orbital periods. Monte Carlo simulations show the effect is significant and is not solely due to an observational selection effect. We also show the effect is stronger than the one already implied by published models that

Shay Zucker; Tsevi Mazeh

2002-01-01

167

Giant Planets  

NASA Astrophysics Data System (ADS)

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

Lunine, J. I.

168

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

PubMed

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

Snellen, Ignas

2014-04-28

169

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

170

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

171

A survey of the outer planets Jupiter, Saturn, Uranus, Neptune, Pluto, and their satellites  

Microsoft Academic Search

A survey of current knowledge about Jupiter, Saturn, Uranus, Neptune, Pluto, and their satellites is presented. The best available\\u000a numerical values are given for physical parameters, including orbital and body properties, atmospheric composition and structure,\\u000a and photometric parameters. The more acceptable current theories of these bodies are outlined with thorough referencing offering\\u000a access to the details. The survey attempts to

R. L. Newburn; S. Gulkis

1973-01-01

172

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

173

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

174

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

175

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

176

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

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

177

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

2007-02-20

178

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

179

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

180

Habitability of Planets Orbiting Binaries Consisting of Solar Mass Twins  

NASA Astrophysics Data System (ADS)

An important problem in astrobiology is the study of the potential habitability of planets orbiting binary stars. Theoretical and observational studies of circumbinary planets indicate that it is not uncommon for circumbinary planets to be located in the habitable zones surrounding main sequence binaries. However, it is also clear that the time evolution of stellar activity of the individual stars in close binaries is of primary concern for the habitability of planets. For example, planets orbiting active stars may lose the entirety of their water budget due to atmospheric mass loss; despite being in the standard radiative habitable zone. Alternatively, stars in some binaries may undergo a reduction in stellar activity due to tidal effects that cause the rotation of the stars to slow faster than single stars. Thereby, magneto-coronal activity is reduced to less aggressive levels, allowing circumbinary planets to maintain surface water. We summarize these effects, which we call the Binary Habitability Mechanism (BHM). We performed orbital integrations of circumbinary, Earth-like, planets and find that resonances play a particularly important role in the stability of habitable zone planets orbiting solar twin binaries in the 20-60 day period range, allowing for the possibility of several habitable planets orbiting some binaries. We present numerical simulations of the effects of colliding winds in binaries containing solar mass twins. We used stellar wind parameters based on solar like conditions for our 3D hydrodynamic simulations. We find devastating effects for close in planets, yet relatively mild stellar wind conditions exist within the circumbinary habitable zone.

Mason, Paul A.; Zuluaga, Jorge I.; Zhilkin, Andrey G.; Bisikalo, Dmitry V.

2015-01-01

181

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

E-print Network

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 ...

Guo, Jianheng

182

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

ERIC Educational Resources Information Center

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

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

2012-01-01

183

Terrestrial Planet Formation in a protoplanetary disk with a local mass depletion: A successful scenario for the formation of Mars  

NASA Astrophysics Data System (ADS)

Models of terrestrial planet formation have been successful in producing terrestrial-class planets with sizes in the range of Venus and Earth. However, these models have generally failed to produce Mars-sized objects around 1.5 AU. The body that is usually formed around Mars' semimajor axis is, in general, much more massive than Mars. Only when Jupiter and Saturn are assumed to have very eccentric orbits, or alternately, if they have experienced a wide inward-then-outward migration in a gas-rich phase, simulations have been able to produce Mars-like bodies. In this work, we have examined a different scenario for the formation of Mars in which a local depletion in the density of the protosolar nebula results in a non-uniform formation of planetary embryos. We have carried out extensive numerical simulations of the formation of terrestrial planets in such a disk for different scales of the local density depletion, and for different orbital configurations of giant planets. Our simulations point to the possibility of the formation of Mars-sized bodies around 1.5 AU, specifically when the scale of the disk local mass-depletion is moderately high (50-75%) and Jupiter and Saturn are initially in their current orbits. In these systems, Mars analogs are formed from the protoplanetary materials that originate in the region of disk where there is no local mass-depletion. Results also indicate that in the same systems Earth-sized planets can form around 1 AU with a substantial amount of water due to accretion of water-rich material originated from past 2 AU. We present the results of our study and discuss their implications for the formation of terrestrial planets in our solar system.

Izidoro, André; Haghighipour, N.; Cabo Winter, O.; Tsuchida, M.

2013-10-01

184

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

185

Search for Earth-Mass Planets and Dark Matter, Too  

E-print Network

Gravitational microlensing is known for baryoninc 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 microlenisng 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.

S. H. Rhie; D. P. Bennett

1996-07-12

186

An Earth-mass planet orbiting ? Centauri B.  

PubMed

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

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

2012-11-01

187

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

188

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

189

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

E-print Network

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

Matthew J. Holman; Norman W. Murray

2004-12-01

190

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

E-print Network

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

Edward R. D. Scott

2006-07-13

191

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

192

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

193

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

194

Protoplanetary disk lifetimes vs. stellar mass and possible implications for giant planet populations  

NASA Astrophysics Data System (ADS)

Aims: We study the dependence of protoplanetary disk evolution on stellar mass using a large sample of young stellar objects in nearby young star-forming regions. Methods: We update the protoplanetary disk fractions presented in our recent work (Paper I of this series) derived for 22 nearby (<500 pc) associations between 1 and 100 Myr. We use a subsample of 1428 spectroscopically confirmed members to study the impact of stellar mass on protoplanetary disk evolution. We divide this sample into two stellar mass bins (2 M? boundary) and two age bins (3 Myr boundary), and use infrared excesses over the photospheric emission to classify objects in three groups: protoplanetary disks, evolved disks, and diskless. The homogeneous analysis and bias corrections allow for a statistically significant inter-comparison of the obtained results. Results: We find robust statistical evidence of disk evolution dependence with stellar mass. Our results, combined with previous studies on disk evolution, confirm that protoplanetary disks evolve faster and/or earlier around high-mass (>2 M?) stars. We also find a roughly constant level of evolved disks throughout the whole age and stellar mass spectra. Conclusions: We conclude that protoplanetary disk evolution depends on stellar mass. Such a dependence could have important implications for gas giant planet formation and migration, and could contribute to explaining the apparent paucity of hot Jupiters around high-mass stars. Appendix A is available in electronic form at http://www.aanda.org

Ribas, Álvaro; Bouy, Hervé; Merín, Bruno

2015-04-01

195

1999 Macmillan Magazines Ltd the planet real, we now know that it is a gas  

E-print Network

© 1999 Macmillan Magazines Ltd the planet real, we now know that it is a gas giantmademainlyofhydrogen,notrock--a solid planet with a mass of 0.63 MJ would havetobethreetimessmallerthanJupiter. Our properties of extrasolar planets. The detection of reflected light from a planet, if confirmed, is the first

Palumbi, Stephen

196

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

197

Formation of giant planets around stars with various masses  

NASA Astrophysics Data System (ADS)

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

Kornet, K.; Wolf, S.; Ró?yczka, M.

2006-11-01

198

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

199

Volatile-rich Earth-Mass Planets in the Habitable Zone  

Microsoft Academic Search

A small planet is not necessarily a terrestrial planet. Planets that form beyond the snow line with too little mass to seed rapid gas accretion (<~10 M?) should be rich in volatile ices like H2O and NH3. Some of these planets should migrate inward by interacting with a circumstellar disk or with other planets. Such objects can retain their volatiles

Marc J. Kuchner

2003-01-01

200

Volatile-Rich Earth-Mass Planets in the Habitable Zone  

Microsoft Academic Search

A small planet is not necessarily a terrestrial planet. Planets that form beyond the snow line with too little mass to seed rapid gas accretion (< ˜ 10 M \\\\bigoplus ) should be rich in volatile ices like H2O and NH3. Some of these planets should migrate inward by interacting with a circumstellar disk or with other planets. Such objects

M. J. Kuchner

2003-01-01

201

Terrestrial planets in high-mass disks without gas giants  

NASA Astrophysics Data System (ADS)

Context. Observational and theoretical studies suggest that planetary systems consisting only of rocky planets are probably the most common in the Universe. Aims: We study the potential habitability of planets formed in high-mass disks without gas giants around solar-type stars. These systems are interesting because they are likely to harbor super-Earths or Neptune-mass planets on wide orbits, which one should be able to detect with the microlensing technique. Methods: First, a semi-analytical model was used to define the mass of the protoplanetary disks that produce Earth-like planets, super-Earths, or mini-Neptunes, but not gas giants. Using mean values for the parameters that describe a disk and its evolution, we infer that disks with masses lower than 0.15 M? are unable to form gas giants. Then, that semi-analytical model was used to describe the evolution of embryos and planetesimals during the gaseous phase for a given disk. Thus, initial conditions were obtained to perform N-body simulations of planetary accretion. We studied disks of 0.1, 0.125, and 0.15 M?. Results: All our simulations form massive planets on wide orbits. For a 0.1 M? disk, 2-3 super-Earths of 2.8 to 5.9 M? are formed between 2 and 5 AU. For disks of 0.125 and 0.15 M?, our simulations produce a 10-17.1 M? planet between 1.6 and 2.7 AU, and other super-Earths are formed in outer regions. Moreover, six planets survive in the habitable zone (HZ). These planets have masses from 1.9 to 4.7 M? and significant water contents ranging from 560 to 7482 Earth oceans, where one Earth ocean represents the amount of water on Earth's surface, which equals 2.8 × 10-4M?. Of the six planets formed in the HZ, three are water worlds with 39%-44% water by mass. These planets start the simulations beyond the snow line, which explains their high water abundances. In general terms, the smaller the mass of the planets observed on wide orbits, the higher the possibility to find water worlds in the HZ. In fact, massive planets can act as a dynamical barrier that prevents the inward diffusion of water-rich embryos located beyond the snow line. Conclusions: Systems without gas giants that harbor super-Earths or Neptune-mass planets on wide orbits around solar-type stars are of astrobiological interest. These systems are likely to harbor super-Earths in the HZ with significant water contents, which missions such as Kepler and Darwin should be able to find.

de Elía, G. C.; Guilera, O. M.; Brunini, A.

2013-09-01

202

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

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

203

Jupiter: The Solar System's Giant  

NASA Technical Reports Server (NTRS)

At more than 10 times the size of the Earth, Jupiter is the largest planet in the solar system. Although not quite large enough to be a sun, it still has its own system of moons and rings. It's huge magnetic field and fast rotation make Jupiter both the most interesting planet and the most dangerous. From the sulfur volcanoes of Io to the frozen water ice ocean of Europa, Jupiter "rocks". Come experience what NASA has learned about the giant planet

Gallagher, Dennis L.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

204

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

205

DISCOVERY AND MASS MEASUREMENTS OF A COLD, 10 EARTH MASS PLANET AND ITS HOST STAR  

SciTech Connect

We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, performed with the gravitational microlensing method. This planet has a mass of m{sub p} = 10.4 {+-} 1.7 M{sub +} and orbits a star of mass M{sub *} = 0.56 {+-} 0.09 M{sub sun} at a semimajor axis of a = 3.2{sub -0.5}{sup +1.9} AU and an orbital period of P = 7.6{sub -1.5}{sup +7+7} yrs. The planet and host star mass measurements are enabled by the measurement of the microlensing parallax effect, which is seen primarily in the light curve distortion due to the orbital motion of the Earth. But the analysis also demonstrates the capability to measure the microlensing 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.

Muraki, Y. [Department of Physics, Konan University, Nishiokamoto 8-9-1, Kobe 658-8501 (Japan); Han, C. [Department of Physics, Chungbuk National University, 410 Seongbong-Rho, Hungduk-Gu, Chongju 371-763 (Korea, Republic of); Bennett, D. P. [Department of Physics, 225 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556 (United States); Suzuki, D.; Sumi, T. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, 464-8601 (Japan); Monard, L. A. G. [Bronberg Observatory, Centre for Backyard Astrophysics, Pretoria (South Africa); Street, R. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Dr., Suite 102, Goleta, CA 93117 (United States); Jorgensen, U. G. [Niels Bohr Institute and Centre for Stars and Planet Formation, Juliane Mariesvej 30, 2100 Copenhagen (Denmark); Kundurthy, P.; Becker, A. C. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Skowron, J.; Gaudi, B. S. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Albrow, M. D. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020 (New Zealand); Fouque, P. [IRAP, CNRS, Universite de Toulouse, 14 avenue Edouard Belin, 31400 Toulouse (France); Heyrovsky, D. [Institute of Theoretical Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Barry, R. K. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Beaulieu, J.-P. [Institut d'Astrophysique de Paris, F-75014, Paris (France); Wellnitz, D. D. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Bond, I. A. [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand); Dong, S., E-mail: cheongho@chungbuk.ac.kr, E-mail: bennett@nd.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

2011-11-01

206

PLANET III: searching for Earth-mass planets via microlensing from Dome C?  

NASA Astrophysics Data System (ADS)

PLANET, the Probing Lensing Anomaly NETwork, is an international team conducting observations of on-going gravitational microlensing events from five sites in the southern hemisphere. Our primary goal is to detect or to put constraints on sub-stellar companions of M dwarfs from the galactic disk. We report the current status and discuss the future prospects. A 2m robotic telescope at Dome C which would benefit from continuous coverage and dream like seeing (median of 0.27 arcsec) is currently the best option for a ground based aggressive search for Earth-mass planets in the habitable zone.

Beaulieu, J. P.; Cassan, A.; Kubas, D.; Albrow, M.; Bennett, D.; Brillant, S.; Caldwell, J. A. R.; Calitz, H.; Cook, K.; Coutures, C.; Dominik, M.; Dominis, D.; Donatowicz, J.; Fouqué, P.; Greenhill, J.; Hill, K.; Hoffman, M.; Horne, K.; Jørgensen, U. G.; Kane, S.; Martin, R.; Mientjes, P.; Menzies, J. M.; Pollard, K.; Sahu, K.; Vinter, C.; Wambsganss, J.; Williams, A.

207

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.

2014-09-18

208

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

NASA Technical Reports Server (NTRS)

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

Barry, Richard K., Jr.

2011-01-01

209

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

210

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

211

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

SciTech Connect

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

Visscher, Channon [Current address: Lunar and Planetary Institute, USRA, Houston, TX 77058-1113 (United States); Lodders, Katharina; Fegley, Bruce, E-mail: visscher@lpi.usra.ed, E-mail: lodders@wustl.ed, E-mail: bfegley@wustl.ed [Planetary Chemistry Laboratory, Department of Earth and Planetary Sciences, McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130-4899 (United States)

2010-06-20

212

GIANT PLANET FORMATION BY DISK INSTABILITY IN LOW MASS DISKS?  

SciTech Connect

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

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

2010-12-20

213

On Jupiter  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the planet Jupiter, including characteristics such as size, surface features, and distance. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. Students gather information and become 'tour guides' of the planet to relay Jovian research to others. Videos can be ordered to complement the lesson. Vocabulary words are supported by audio-clips and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans are provided.

214

The formation of terrestrial planets  

NASA Astrophysics Data System (ADS)

Previous numerical simulations of the process of formation of the terrestrial planets led to results which typically have two problems: (i) the final orbits of the planets are too eccentric and inclined relative to the real orbits of the terrestrial planet system and (ii) the planets form too slowly with respect to the time indicated by the Hf-W chronometer for the Earth-Moon system. It is usually thought that these problems are due to the fact that the simulations do not account for a population of small planetesimals carrying cumulatively a mass comparable to the mass of the planetary embryos. We have done new simulations, starting with a system of 25 Mars-mass embryos initially distributed from 0.5 to 4 AU, embedded in a disk of 2.5 Earth masses of planetesimals, modeled with 1,000 individual equal-mass particles. We have performed 8 simulations. 4 simulations assumed Jupiter and Saturn initially on their current orbits, while the remaining 4 simulations assumed that the two giant planets had circular orbits, consistent with the `Nice model' on the origin of the late heavy bombardment (Gomes et al., 2005) and on the giant planets' orbital architecture (Tsiganis et al., 2005). The simulations starting with Jupiter on an eccentric orbit lead to the formation of a system of terrestrial planets whose angular momentum deficit is 7 times smaller than that obtained in previous simulations (Chambers, 2001), whereas the formation timescale is three times shorter. This confirms that the dynamical friction exerted by planetesimals onto the forming planets is an essential ingredient in terrestrial planet formation. Interestingly, the final terrestrial planets achieved in these simulations are dynamically colder than the real terrestrial planets. The simulations starting with Jupiter on a circular orbit still produce planets which are slightly too dynamically excited (by about 50%) and which form too slowly (by a factor of 2). These problems are expected to disappear in future simulations modeling the planetesimal disk with a larger number of particles, or accounting for the regeneration of planetesimals during giant collisions among embryos. A main difference between the planets formed in the eccentric Jupiter case with respect to the circular Jupiter case is that the former do not acquire a significant amount of mass from beyond 2.5 AU. These planets are therefore expected to be more deficient in water, possibly too dry with respect to the Earth.

Morbidelli, A.; O'Brien, D.

215

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

2009-01-12

216

Secular Chaos and the Production of Hot Jupiters  

NASA Astrophysics Data System (ADS)

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; Lithwick, Yoram

2011-07-01

217

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

218

Volatile-Rich Earth-Mass Planets in the Habitable Zone  

Microsoft Academic Search

A small planet is not necessarily a terrestrial planet. Planets that form\\u000abeyond the snow line with too little mass to seed rapid gas accretion (<~ 10\\u000aEarth masses) should be rich in volatile ices like water and ammonia. Some of\\u000athese planets should migrate inward by interacting with a circumstellar disk or\\u000awith other planets. Such objects can retain

Marc J. Kuchner

2003-01-01

219

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

E-print Network

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

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

2014-01-01

220

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

221

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

222

MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING  

SciTech Connect

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

Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Backer, D. C. [Department of Astronomy and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720 (United States); Bailes, M.; Bhat, N. D. R.; Van Straten, W. [Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122 (Australia); Coles, W. [Electrical and Computer Engineering, University of California at San Diego, La Jolla, CA (United States); Demorest, P. B. [National Radio Astronomy Observatory, Charlottesville, VA 22901 (United States); Ferdman, R. D.; Purver, M. B. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Folkner, W. M. [Jet Propulsion Laboratory, 4800 Oak Grove Dr, Pasadena, CA 91109-8099 (United States); Hotan, A. W. [Curtin Institute of Radio Astronomy, Curtin University, Bentley, WA 6102 (Australia); Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Lommen, A. N. [Franklin and Marshall College, 415 Harrisburg Pike, Lancaster, PA 17604 (United States); Nice, D. J. [Physics Department, Lafayette College, Easton, PA 18042 (United States); Stairs, I. H., E-mail: champion@pulsarastronomy.ne [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)

2010-09-10

223

Predicting Planets in Known Extra-Solar Planetary Systems II: Testing for Saturn-mass Planets  

E-print Network

Recent results have shown that many of the known extrasolar planetary systems contain regions which are stable for massless test particles. We examine the possibility that Saturn-mass planets exist in these systems, just below the detection threshold, and attempt to predict likely orbital parameters for such unseen planets. To do this, we insert a Saturn-mass planet into the stable regions of these systems and integrate its orbit for 100 million years. We conduct 200-600 of these experiments to test parameter space in HD37124, HD38529, 55Cnc, and HD74156. In HD37124 the global maximum of the survival rate of Saturns in parameter space is at semimajor axis a = 1.03 AU, eccentricity e=0.1. In HD38529, only 5% of Saturns are unstable, and the region in which a Saturn could survive is very broad, centered on 0.5

Sean N. Raymond; Rory Barnes

2004-04-09

224

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

225

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

226

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

SciTech Connect

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

Lykawka, Patryk Sofia [Astronomy Group, Faculty of Social and Natural Sciences, Kinki University, Shinkamikosaka 228-3, Higashiosaka-shi, Osaka 577-0813 (Japan); Ito, Takashi, E-mail: patryksan@gmail.com [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)

2013-08-10

227

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

E-print Network

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

Heller, René

2015-01-01

228

Making More Terrestrial Planets  

Microsoft Academic Search

The results of 16 new 3D N-body simulations of the final stage of the formation of the terrestrial planets are presented. These N-body integrations begin with 150–160 lunar-to-Mars size planetary embryos, with semi-major axes 0.3Jupiter and Saturn. Two initial mass distributions are examined: approximately uniform masses, and a bimodal distribution with a few large

J. E. Chambers

2001-01-01

229

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

E-print Network

Stability of Earth-Mass Planets in the Habitable Zones of Extrasolar Planetary Systems Dr. Ravi Kumar Kopparapu Dept. of Geosciences, College of Earth and Mineral Science Over 500 planets orbiting and Saturn but in the last couple of years several "super-earths", planets with mass less than 10 times Earth

Bjørnstad, Ottar Nordal

230

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

231

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

232

Discovery of a Cool, Low-Mass, Extra-solar Planet by Gravitational Microlensing  

NASA Astrophysics Data System (ADS)

We present photometry from the PLANET, OGLE, and MOA Collaborations which reveals the first discovery of a low-mass extra-solar planet by the gravitational microlensing method. The newly discovered planet orbits a low-mass star in the Galactic bulge, and its most probable mass is smaller than the mass of any other planet found orbiting a main sequence star, although the error bars on the planetary mass overlap with those of GL 876 d. The separation of the newly discovered planet from its host star is about 3 AU, and so it represents the first of a class of cool, low-mass planets that are currently detectable only by the gravitational microlensing method. This discovery appears to support a prediction of the core-accretion model for planet formation.

Bennett, D. P.; PLANET Collaboration; OGLE Collaboration; MOA Collaboration

2005-12-01

233

Lone Planet Under a Cosmic Magnifying Glass - Duration: 0:45.  

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...

234

Observed properties of extrasolar planets.  

PubMed

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

Howard, Andrew W

2013-05-01

235

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

236

Microlensing Search for Extrasolar Planets  

NASA Astrophysics Data System (ADS)

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

Cassan, A.; Kubas, D.

2007-07-01

237

Microlensing search for extrasolar planets  

E-print Network

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

A. Cassan; D. Kubas

2006-12-01

238

Phase light curves for extrasolar Jupiters and Saturns  

E-print Network

We predict how a remote observer would see the brightness variations of giant planets similar to Jupiter and Saturn as they orbit their central stars. We model the geometry of Jupiter, Saturn and Saturn's rings for varying orbital and viewing parameters. Scattering properties for the planets and rings at wavelenghts 0.6-0.7 microns follow Pioneer and Voyager observations, namely, planets are forward scattering and rings are backward scattering. Images of the planet with or without rings are simulated and used to calculate the disk-averaged luminosity varying along the orbit, that is, a light curve is generated. We find that the different scattering properties of Jupiter and Saturn (without rings) make a substantial difference in the shape of their light curves. Saturn-size rings increase the apparent luminosity of the planet by a factor of 2-3 for a wide range of geometries. Rings produce asymmetric light curves that are distinct from the light curve of the planet without rings. If radial velocity data are available for the planet, the effect of the ring on the light curve can be distinguished from effects due to orbital eccentricity. Non-ringed planets on eccentric orbits produce light curves with maxima shifted relative to the position of the maximum planet's phase. Given radial velocity data, the amount of the shift restricts the planet's unknown orbital inclination and therefore its mass. Combination of radial velocity data and a light curve for a non-ringed planet on an eccentric orbit can also be used to constrain the surface scattering properties of the planet. To summarize our results for the detectability of exoplanets in reflected light, we present a chart of light curve amplitudes of non-ringed planets for different eccentricities, inclinations, and the viewing azimuthal angles of the observer.

Ulyana A. Dyudina; Penny D. Sackett; Daniel D. R. Bayliss; Sara Seager; Carolyn C. Porco; Henry B. Throop; Luke Dones

2004-06-17

239

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

240

Detectability of extrasolar planets in radial velocity surveys  

Microsoft Academic Search

Radial velocity surveys are beginning to reach the time baselines required to detect Jupiter analogues, as well as sub-Saturn mass planets in close orbits. Therefore, it is important to understand the sensitivity of these surveys at long periods and low amplitudes. In this paper, I derive analytical expressions for the detectability of planets at both short and long periods, for

Andrew Cumming

2004-01-01

241

The internal structure of the planets Mercury, Venus, Mars and Jupiter according to the Savic-Kasanin theory  

Microsoft Academic Search

The internal structure of Mercury, Venus, Mars, and Jupiter is considered in the framework of the Savic-Kasanin theory of the behavior of materials under high pressure. The main hypothesis underlying the theory is based on the deformation of the electron shells by the dislocation and ejection of electrons from atoms in a given material. This theory is discussed in relation

P. Savic

1981-01-01

242

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

E-print Network

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

Batygin, Konstantin

2015-01-01

243

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

PubMed

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

Batygin, Konstantin; Laughlin, Greg

2015-04-01

244

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 ...

Ms. Anderson

2011-04-07

245

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.

246

Volatile-Rich Earth-Mass Planets in the Habitable Zone  

E-print Network

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

Marc J. Kuchner

2003-08-28

247

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

248

Acoustic oscillations of Jupiter  

NASA Technical Reports Server (NTRS)

We calculate low-degree l acoustic (p-mode) oscillations of the giant planet Jupiter. We use two Jupiter models, both of which contain a rocky core, an ice mantle, and a hydrogen-rich envelope. One of the models incorporates the 'plasma phase transition' of hydrogen, a first-order phase transition that yields a density discontinuity in the hydrogen-rich envelope. Our calculations of the acoustic oscillation spectrum of Jupiter have taken account of the effects of the rapid rotation of the planet: the Coriolis force, centrifugal force, and deformation of the equilibrium state. The p-mode frequency spectra of the Jupiter models are summarized in several echelle diagrams. We show that the frequency spectra of the low-degree p-modes are strongly affected by the existence of the rocky core and by avoided crossings among high radial-order p-modes with different l's.

Lee, Umin

1993-01-01

249

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

250

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

251

Extrasolar Binary Planets I: Formation by tidal capture during planet-planet scattering  

E-print Network

We have investigated i) 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 ii) the following long-term orbital evolution due to planet-planet and planet-star {\\it quasi-static} tides. For the initial evolution in phase i), 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 semi-major axes of the planets, while ejection and merging rates sensitively depend on the semi-major 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 ...

Ochiai, H; Ida, S

2014-01-01

252

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.

253

The PLANET Microlensing Campaign: Implications for Planets around Galactic Disk and Bulge Stars  

NASA Astrophysics Data System (ADS)

With round-the-clock monitoring of galactic bulge microlensing events, the PLANET experiment constrains the abundance and can yield the discovery of planets down to the mass of earth around galactic disk and bulge stars. Data taken until 1999 imply that less than 1/3 of bulge M-dwarfs are surrounded by jupiter-mass companions at orbital radii between 1 and 4 AU. The current rate of microlensing alerts allows 15--25 jupiters and 1--3 earths to be probed per year.

Dominik, M.; Albrow, M. D.; Beaulieu, J.-P.; Caldwell, J. A. R.; Cassan, A.; Coutures, C.; Greenhill, J.; Hill, K.; Fouqué, P.; Horne, K.; Jorgensen, U. G.; Kane, S.; Kubas, D.; Martin, R.; Menzies, J.; Pollard, K. R.; Sahu, K.; Wambsganss, J.; Watson, R.; Williams, A.

2004-12-01

254

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

255

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

256

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

257

The Role of Giant Planets in Terrestrial Planet Formation  

NASA Astrophysics Data System (ADS)

The dynamical structure of the outer planetary system has played a critical role in determining the sizes, numbers, and habitability of the terrestrial planets. In 1996, Wetherill showed that the presence of Jupiter affects the masses of planets in the Habitable Zone of the Sun. In addition, in our solar system the giant planets control the dynamics of most of Earth's impactors, which consist of objects from the asteroid belt, the Kuiper belt, the scattered comet disk, and the Oort cloud. At early times, these impactors may have been responsible for supplying the Earth with a significant fraction of its water, organics, and atmospheric volatiles. At later times, they are responsible for causing at least some mass extinctions. Recent observations have demonstrated that giant planet configurations can show startling variations from system to system. (Although the searches for extra-solar planets have yet to reveal anything about what `typical systems' are like due to strong observational biases.) The question therefore naturally arises: What kind of outer planetary systems can support habitable terrestrial planets? The Exobiology Program is funding us to undertake the first comprehensive study of the coupling between outer solar system architectures and inner solar system habitability. The first stage of this program was to construct a wide range of outer planetary systems. The results of this work can be found at www.boulder.swri.edu/ hal/diversity.html. Here we present a preliminary report on simulations of the formation of terrestrial planets in two of these synthetic outer planetary systems. The first contains 5 planets; three of which lie between 3.7 and 11AU and have a combined mass of 2600 Earth-masses ( 8 Jupiter-masses). The second system contains 7 planets between 4 and 35AU; the largest of which is only 26 Earth-masses ( 1.5 Neptune masses).

Levison, H. F.; Duncan, M. J.; Agnor, C. B.

2000-05-01

258

Directly Imaging Tidally Powered Migrating Jupiters  

NASA Astrophysics Data System (ADS)

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 ~ Gyr-"old" main-sequence stars, they can be as "hot" as young Jupiters at ~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 ~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 ~ 100-1000 L Jup(2 × 10-7-2 × 10-6 L ?) during a typical ~ 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. ~10 such planets are expected to exist around FGK dwarfs within ~50 pc. Long-period radial velocity planets are viable candidates, and the highly eccentric planet HD 20782b at maximum angular separation ~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

2013-01-01

259

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

260

Jupiter with Io Crossing  

NASA Technical Reports Server (NTRS)

Jupiter's satellite Io poses before the giant planet in this photo returned January 17, 1979, from a distance of 29 million miles (47 million kilometers). The satellite's shadow can be seen falling on the face of Jupiter at left. Io is traveling from left to right in its one-and-three-quarter-day orbit around Jupiter. Even from this great distance the image of Io shows dark poles and a bright equatorial region. Voyager will make its closest approach to Jupiter -- 174,000 miles (280,000 kilometer) -- on March 5. It will then continue to Saturn in November 1980, Meanwhile Voyager 2, a sister spacecraft, will fly past Jupiter July 9, 1979, and reach Saturn in August 1981. This color image was taken through orange, green and blue filters. The Voyagers are managed for NASA's Office of Space Science by Jet Propulsion Laboratory.

1979-01-01

261

The growth of Jupiter and Saturn and the capture of Trojans  

NASA Astrophysics Data System (ADS)

We have studied the capture of planetesimals in Trojan-type orbits by a growing proto-planet. The change of the gravity field due to the mass growth causes a significant fraction of planetesimals orbiting nearby to be trapped as Trojans of the proto-planet. After a planetesimal is captured on a Trojan-type orbit, the libration amplitude of its critical argument is consistently reduced by the further mass growth of the proto-planet. The dynamical mechanism is discussed and the characteristics of the Trojan population captured by Jupiter during its growth are analysed. We find an interesting mechanism which could explain the observed high inclination Trojans. The synergy of a Kozai secular resonance with the growth of Jupiter's mass generates high inclination Trojans from low inclination-high eccentricity planetesimals orbiting near the growing proto-planet. The libration amplitudes of the model Trojans trapped by the mass-growth of Jupiter are higher compared to those of the observed Trojans. A possible mechanism that decreases the libration amplitudes of the model population is collisional evolution. We also show that the simultaneous formation of Jupiter and Saturn strongly inhibits the capture of planetesimals as Saturn Trojans. The interference of the 1:1 resonance with a secular resonance and, in some cases, also with the 5:2 resonance with Jupiter (Innanen and Mikkola, 1989), generates instability and causes the ejection of most Saturn Trojans out of resonance before the end of Saturn's mass growth.

Marzari, F.; Scholl, H.

1998-11-01

262

Microlensing Sensitivity to Earth-Mass Planets in the Habitable Zone  

Microsoft Academic Search

Microlensing is one of the most powerful methods that can detect extrasolar planets, and a future space-based survey with a high monitoring frequency is proposed to detect a large sample of Earth-mass planets. In this paper, we examine the sensitivity of the future microlensing survey to Earth-mass planets located in the habitable zone. For this, we estimate the fraction of

Byeong-Gon Park; Young-Beom Jeon; Chung-Uk Lee; Cheongho Han

2006-01-01

263

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

SciTech Connect

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

Rivera, Eugenio J.; Laughlin, Gregory; Vogt, Steven S.; Meschiari, Stefano [UCO/Lick Observatory, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Butler, R. Paul [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington DC, 20015-1305 (United States); Haghighipour, Nader, E-mail: rivera@ucolick.or [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Monoa, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

2010-08-10

264

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

265

A Systematic Study of the Final Masses of Gas Giant Planets  

E-print Network

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

T. Tanigawa; M. Ikoma

2007-05-30

266

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.

267

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

268

Radii, Masses, Densities, and Occurrence for Planets within 0.25 AU  

NASA Astrophysics Data System (ADS)

We report the observed distribution of planet radii, masses, and orbital distances for orbital periods less than 50 days around Solar-type (GK) stars. We draw from extensive Doppler and Kepler measurements that offer good completeness for planets with radii as small as 2.0 Earth-radii. We include the photometric signal-to-noise ratio for all 156,000 target stars to determine planet detectability as a function of planet radius and orbital period for each target. We consider Kepler target stars within the ``Solar subset'' having Teff = 4100--6100 K, logg = 4.0--4.9, and stars brighter than Kepler magnitude 15. The resulting occurrence of planets as a function of planet radius and orbital period increases strongly toward the smallest radii (2 Earth-radii) and toward longer orbital periods ( up to 50 days, 0.25 AU). Summing over all orbital periods (P<50 d), the distribution of planet radii increases rapidly with smaller planet size. This high occurrence of smaller planets supports core-accretion theory but disagrees with the theory of migration in a gaseous disk that predicts a desert at Super-Earth and Neptune sizes for close-in orbits, which is not seen. Planets with orbital periods less than 2 days are extremely rare. We explore the densities of exoplanets by finding self-consistent mappings from the distributions of planet radius (from Kepler) to mass (from Doppler).

Marcy, Geoffrey W.; Howard, A.; Kepler Team

2011-05-01

269

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

SciTech Connect

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

Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G., E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2012-04-01

270

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

271

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

272

On the Mass-Period Distributions and Correlations of Extrasolar Planets  

E-print Network

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

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

2007-09-05

273

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

274

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

SciTech Connect

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.

Agol, Eric; /Washington U., Seattle, Astron. Dept.; Steffen, Jason H.; /Fermilab

2006-10-01

275

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

NASA Astrophysics Data System (ADS)

We present a combined analysis of all publicly available visible Hubble Space Telescope observations of transits of the planet HD 209458b. We derive the times of transit, planet radius, inclination, period, and ephemeris. We then use the times of transit to place constraints on the existence of secondary planets in the system. We show that planets near an Earth-mass can be ruled out in a low-order mean-motion resonance, while planets less than an Earth-mass are ruled out in an 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.

Agol, Eric; Steffen, Jason H.

2007-01-01

276

Survival of Terrestrial Planets in the Presence of Giant Planet Migration  

E-print Network

The presence of ``Hot Jupiters'', Jovian mass planets with very short orbital periods orbiting nearby main sequence stars, has been proposed to be primarily due to the orbital migration of planets formed in orbits initially much further from the parent star. The migration of giant planets would have profound effects on the evolution of inner terrestrial planets in these systems, and previous analyses have assumed that no terrestrial planets survive after migration has occurred. We present numerical simulations showing that a significant fraction of terrestrial planets could survive the migration process, eventually returning to circular orbits relatively close to their original positions. A fraction of the final orbits are in the Habitable Zone, suggesting that planetary systems with close-in giant planets are viable targets for searches for Earth-like habitable planets around other stars.

Avi M. Mandell; Steinn Sigurdsson

2003-11-10

277

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

SciTech Connect

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

Morbidelli, Alessandro; Brasser, Ramon [Departement Cassiopee, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d'Azur, CNRS 4, 06304 Nice (France); Gomes, Rodney [Observatrio Nacional, Rua General Jos Cristino 77, CEP 20921-400, Rio de Janeiro, RJ (Brazil); Levison, Harold F. [Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States); Tsiganis, Kleomenis [Department of Physics, Aristotle University of Thessaloniki, 54 124 Thessaloniki (Greece)

2010-11-15

278

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

279

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

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)  

E-print Network

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

Schmitt, Joseph R.

281

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.

282

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

E-print Network

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

Johnson, Robert E.

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

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, brown dwarfs, and extrasolar giant planets (EGPs)--are ideal environments for the formation of molecules

Fegley Jr., Bruce

285

Taxonomy of the extrasolar planet.  

PubMed

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

Plávalová, Eva

2012-04-01

286

Atmospheric Escape by Magnetically Driven Wind from Gaseous Planets  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

287

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

Microsoft Academic Search

We analyze 8 years of precise radial velocity measurements from the Keck\\u000aPlanet Search, characterizing the detection threshold, selection effects, and\\u000acompleteness of the survey. We carry out a systematic search for planets by\\u000aassessing the false alarm probability associated with Keplerian orbit fits to\\u000athe data. This allows us to understand the detection threshold for each star in\\u000aterms

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

2008-01-01

288

Sharpening Up Jupiter  

NASA Astrophysics Data System (ADS)

New image-correction technique delivers sharpest whole-planet ground-based picture ever A record two-hour observation of Jupiter using a superior technique to remove atmospheric blur has produced the sharpest whole-planet picture ever taken from the ground. The series of 265 snapshots obtained with the Multi-Conjugate Adaptive Optics Demonstrator (MAD) prototype instrument mounted on ESO's Very Large Telescope (VLT) reveal changes in Jupiter's smog-like haze, probably in response to a planet-wide upheaval more than a year ago. Sharpening Up Jupiter ESO PR Photo 33/08 Sharpening Up Jupiter Being able to correct wide field images for atmospheric distortions has been the dream of scientists and engineers for decades. The new images of Jupiter prove the value of the advanced technology used by MAD, which uses two or more guide stars instead of one as references to remove the blur caused by atmospheric turbulence over a field of view thirty times larger than existing techniques [1]. "This type of adaptive optics has a big advantage for looking at large objects, such as planets, star clusters or nebulae," says lead researcher Franck Marchis, from UC Berkeley and the SETI Institute in Mountain View, California, USA. "While regular adaptive optics provides excellent correction in a small field of view, MAD provides good correction over a larger area of sky. And in fact, were it not for MAD, we would not have been able to perform these amazing observations." MAD allowed the researchers to observe Jupiter for almost two hours on 16 and 17 August 2008, a record duration, according to the observing team. Conventional adaptive optics systems using a single Jupiter moon as reference cannot monitor Jupiter for so long because the moon moves too far from the planet. The Hubble Space Telescope cannot observe Jupiter continuously for more than about 50 minutes, because its view is regularly blocked by the Earth during Hubble's 96-minute orbit. Using MAD, ESO astronomer Paola Amico, MAD project manager Enrico Marchetti and Sébastien Tordo from the MAD team tracked two of Jupiter's largest moons, Europa and Io - one on each side of the planet - to provide a good correction across the full disc of the planet. "It was the most challenging observation we performed with MAD, because we had to track with high accuracy two moons moving at different speeds, while simultaneously chasing Jupiter," says Marchetti. With this unique series of images, the team found a major alteration in the brightness of the equatorial haze, which lies in a 16 000-kilometre wide belt over Jupiter's equator [2]. More sunlight reflecting off upper atmospheric haze means that the amount of haze has increased, or that it has moved up to higher altitudes. "The brightest portion had shifted south by more than 6000 kilometres," explains team member Mike Wong. This conclusion came after comparison with images taken in 2005 by Wong and colleague Imke de Pater using the Hubble Space Telescope. The Hubble images, taken at infrared wavelengths very close to those used for the VLT study, show more haze in the northern half of the bright Equatorial Zone, while the 2008 VLT images show a clear shift to the south. "The change we see in the haze could be related to big changes in cloud patterns associated with last year's planet-wide upheaval, but we need to look at more data to narrow down precisely when the changes occurred," declares Wong.

2008-10-01

289

Diffusivity of heavy elements in Jupiter and Saturn  

NASA Astrophysics Data System (ADS)

Recent work has suggested that gas giant planets such as Jupiter and Saturn may not consist of a small number of fully convective and chemically homogenous layers as has been conventionally assumed, but instead may be chemically inhomogeneous with convective redistribution of elements limited by semiconvection. Constructing accurate planetary models which include semiconvective processes requires accurate estimates of the diffusion constants of minority chemical species in planetary fluids, which have not previously been available. In this work we use ab initio density functional molecular dynamics simulations to simulate the diffusion of heavy elements (specifically carbon, silicon, iron) in hydrogen-helium mixtures at conditions corresponding to giant planet deep interiors. We find diffusivities at the high end of the previously proposed range, and estimate that semiconvective processes may be able to redistribute a substantial fraction of Jupiter's core mass within the planet's age.

Wilson, Hugh F.

2015-04-01

290

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 the very young brown dwarfs at several hundred as- tronomical units from their companions de- scribed in this paper and the close (0.5 to 10 astronomical units) extrasolar giant planets and brown dwarfs around

Zreda, Marek

291

On Stellar Activity Enhancement Due to Interactions with Extrasolar Giant Planets  

Microsoft Academic Search

We present a first attempt to identify and quantify possible interactions between recently discovered extrasolar giant planets (and brown dwarfs) and their host stars, resulting in activity enhancement in the stellar outer atmospheres. Many extrasolar planets have masses comparable to or larger than Jupiter and are within a distance of 0.5 AU, suggesting the possibility of their significant influence on

Manfred Cuntz; Steven H. Saar; Zdzislaw E. Musielak

2000-01-01

292

ExtraSolar Planets Finding Extrasolar Planets. I  

E-print Network

systems have been found. No terrestrial planets are yet known (smallest: 7.5M) The COROT and KEPLER missions are designed to find terrestrial planets using transits Hot Jupiters predominate around young in the Galaxy Hot Jupiters may indicate very different systems We can't say much about terrestrial planets yet

Walter, Frederick M.

293

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

294

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

295

The stability of the orbits of Earth-mass planets in the habitable zone of 47 Ursae Majoris  

Microsoft Academic Search

We have investigated whether Earth-mass planets could survive in the habitable zone (HZ) of the 47 Ursae Majoris system. Mixed-variable symplectic numerical integration has been used to investigate the orbits of putative Earth-mass planets. Whereas the 47 UMa system as previously known, with just one giant planet, could have Earth-mass planets that remain confined to the HZ for a fairly

B. W. Jones; P. N. Sleep

2002-01-01

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

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

298

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

299

Microlensing Sensitivity to Earth-mass Planets in the Habitable Zone  

E-print Network

Microlensing is one of the most powerful methods that can detect extrasolar planets and a future space-based survey with a high monitoring frequency is proposed to detect a large sample of Earth-mass planets. In this paper, we examine the sensitivity of the future microlensing survey to Earth-mass planets located in the habitable zone. For this, we estimate the fraction of Earth-mass planets that will be located in the habitable zone of their parent stars by carrying out detailed simulation of microlensing events based on standard models of the physical and dynamic distributions and the mass function of Galactic matter. From this investigation, we find that among the total detectable Earth-mass planets from the survey, those located in the habitable zone would comprise less than 1% even under a less-conservative definition of the habitable zone. We find the main reason for the low sensitivity is that the projected star-planet separation at which the microlensing planet detection efficiency becomes maximum (lensing zone) is in most cases substantially larger than the median value of the habitable zone. We find that the ratio of the median radius of the habitable zone to the mean radius of the lensing zone is roughly expressed as $d_{\\rm HZ}/r_{\\rm E}\\sim 0.2(m/0.5 M_\\odot)^{1/2}$.

Byeong-Gon Park; Young-Beom Jeon; Chung-Uk Lee; Cheongho Han

2006-01-31

300

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

301

Jump to Jupiter  

NSDL National Science Digital Library

This is a lesson about the size and scale of the planets in the solar system. Learners will help create and then navigate an outdoor course of the traditional planets (including dwarf planet Pluto), which are represented by small common objects. By counting the jumps needed to reach each object, learners experience firsthand the vast scale of our solar system. The activity should be done in a large outdoor area. 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.

2012-08-26

302

SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars  

E-print Network

We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of $2.86\\pm0.35~{\\rm M_{Jup}}$ and a radius of $1.13^{+0.26}_{-0.18}~{\\rm R_{Jup}}$, and it orbits a G0, metallic ([Fe/H]=$0.35\\pm0.15$) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of $T_{eq}=1000 \\pm 45$ K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of $2.82\\pm 0.52~{\\rm M_{Jup}}$ and a radius of $1.45\\pm0.16~{\\rm R_{Jup}}$, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the ...

Almenara, J M; Bouchy, F; Havel, M; Bruno, G; Hébrard, G; Diaz, R F; Deleuil, M; Barros, S C C; Boisse, I; Bonomo, A; Montagnier, G; Santerne, A

2015-01-01

303

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

304

24Planet Fractions and Scales Some of the planets in our  

E-print Network

2/5 = 2/55 x Jupiter. Problem 8 - The Dwarf Planet Pluto is 1/3 the size of Mars. How large24Planet Fractions and Scales Some of the planets in our solar system are much bigger than Earth as big as Mars, but only 1/11 the size of Jupiter. How large is Jupiter compared to Mars? Problem 3

305

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

306

Shaping of the Inner Solar System by the Gas-Driven Migration of Jupiter  

NASA Astrophysics Data System (ADS)

A persistent difficulty in terrestrial planet formation models is creating Mars analogs with the appropriate mass: Mars is typically an order of magnitude too large in simulations. Some recent work found that a small Mars can be created if the planetesimal disk from which the planets form has an outermost edge at 1.0 AU. However, that work and no previous work could produce a truncation of the planetesimal disk while also explaining the mass and structure of the asteroid belt. We show that gas-driven migration of Jupiter inward to 1.5 AU, before its subsequent outward migration, can truncate the disk and repopulate the asteroid belt. This dramatic migration history of Jupiter suggests that the dynamical behavior of our giant planets was more similar to that inferred for extra-solar planets than previously thought, as both have been characterised by substantial radial migration.

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

2014-04-01

307

Habitable zones for Earth-mass planets in multiple planetary systems  

Microsoft Academic Search

We perform numerical simulations to study the Habitable zones (HZs) and dynamical structure for Earth-mass planets in multiple planetary systems. For example, in the HD 69830 system, we extensively explore the planetary configuration of three Neptune-mass companions with one massive terrestrial planet residing in 0.07 AU <= a <= 1.20 AU, to examine the asteroid structure in this system. We

Jianghui Ji; Lin Liu; Hiroshi Kinoshita; Guangyu Li

2008-01-01

308

Radial velocity survey for planets and brown dwarf companions to very young brown dwarfs and very low-mass stars in ChaI with UVES at the VLT  

E-print Network

We present results of a radial velocity (RV) survey for planets and brown dwarf (BD) companions to very young BDs and (very) low-mass stars (VLMSs) in ChaI. High-resolution echelle spectra of ChaHa1-8 and 12 (M6-M8), and B34, CHXR74, Sz23 (M2.5-M5) were taken with UVES / VLT between 2000 and 2004. The achieved precision (40 to 670 m/s) is sufficient to detect Jupiter mass planets around the targets. This first RV survey of very young BDs probes multiplicity which is a key parameter for formation in an as yet unexplored domain, in terms of age, mass, and orbital separation. We find that the subsample of ten BDs and VLMSs (M150 days, which cannot be explained by rotational modulation. An alternative explanation are giant planets / BDs of at least a few Jupiter masses orbiting with periods of several months or longer. Thus, the presented RV data indicate that orbital periods of companions to very young BDs and (V)LMSs are possibly several months or longer, and that orbital separations are > 0.2 AU. This parameter range has not been covered for all targets yet, but will be probed by follow-up observations.

V. Joergens

2005-10-05

309

The Pull of the Planets  

NSDL National Science Digital Library

Learners will model the gravitational fields of planets on a flexible surface. Children 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 Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

2012-12-19

310

Constraints on the mass of a habitable planet with water of nebular origin  

E-print Network

From an astrobiological point of view, special attention has been paid to the probability of habitable planets in extrasolar systems. The purpose of this study is to constrain a possible range of the mass of a terrestrial planet that can get water. We focus on the process of water production through oxidation of the atmospheric hydrogen--the nebular gas having been attracted gravitationally--by oxide available at the planetary surface. For the water production to work well on a planet, a sufficient amount of hydrogen and enough high temperature to melt the planetary surface are needed. We have simulated the structure of the atmosphere that connects with the protoplanetary nebula for wide ranges of heat flux, opacity, and density of the nebular gas. We have found both requirements are fulfilled for an Earth-mass planet for wide ranges of the parameters. We have also found the surface temperature of planets of <= 0.3 Earth masses is lower than the melting temperature of silicate (~ 1500K). On the other hand, a planet of more than several Earth masses becomes a gas giant planet through runaway accretion of the nebular gas.

Masahiro Ikoma; Hidenori Genda

2006-06-06

311

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

312

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

313

SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars  

NASA Astrophysics Data System (ADS)

We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of 2.86 ± 0.35 MJup and a radius of 1.13 +0.26-0.18 RJup, and it orbits a G0, metallic ([ Fe/H ] = 0.35 ± 0.15) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of Teq = 1000 ± 45 K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of 2.82 ± 0.52 MJup and a radius of 1.45 ± 0.16 RJup, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the planet. On the other hand, KOI-680b has a much lower mass of 0.84 ± 0.15 MJup and requires less extra-dissipation to explain its uncommonly large radius of 1.99 ± 0.18 RJup. It is one of the biggest transiting planets characterized so far, and it orbits a subgiant F9-star well on its way to the red giant stage, with an orbital period of 8.6 days. With host stars of masses of 1.46 ± 0.17 M? and 1.54 ± 0.09 M?, respectively, KOI-206b, and KOI-680b are interesting objects for theories of formation and survival of short-period planets around stars more massive than the Sun. For those two targets, we also find signs of a possible distant additional companion in the system. Based on observations made with SOPHIE on the 1.93-m telescope at the Observatoire de Haute-Provence (CNRS), France.Figures 11-14 are available in electronic form at http://www.aanda.org

Almenara, J. M.; Damiani, C.; Bouchy, F.; Havel, M.; Bruno, G.; Hébrard, G.; Diaz, R. F.; Deleuil, M.; Barros, S. C. C.; Boisse, I.; Bonomo, A. S.; Montagnier, G.; Santerne, A.

2015-03-01

314

The Mass of Kepler-93b and The Composition of Terrestrial Planets  

E-print Network

Kepler-93b is a 1.478 +/- 0.019 Earth radius planet with a 4.7 day period around a bright (V=10.2), astroseismically-characterized host star with a mass of 0.911+/-0.033 solar masses and a radius of 0.919+/-0.011 solar radii. Based on 86 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 32 archival Keck/HIRES observations, we present a precise mass estimate of 4.02+/-0.68 Earth masses. The corresponding high density of 6.88+/-1.18 g/cc is consistent with a rocky composition of primarily iron and magnesium silicate. We compare Kepler-93b to other dense planets with well-constrained parameters and find that between 1-6 Earth masses, all dense planets including the Earth and Venus are well-described by the same fixed ratio of iron to magnesium silicate. There are as of yet no examples of such planets with masses > 6 Earth masses: All known planets in this mass regime have lower densities requiring significant fractions of volatiles or H/He gas. We also co...

Dressing, Courtney D; Dumusque, Xavier; Gettel, Sara; Pepe, Francesco; Cameron, Andrew Collier; Latham, David W; Molinari, Emilio; Udry, Stephane; Affer, Laura; Bonomo, Aldo S; Buchhave, Lars A; Cosentino, Rosario; Figueira, Pedro; Fiorenzano, Aldo F M; Harutyunyan, Avet; Haywood, Raphaelle D; Johnson, John Asher; Lopez-Morales, Mercedes; Lovis, Christophe; Malavolta, Luca; Mayor, Michel; Micela, Giusi; Motalebi, Fatemeh; Nascimbeni, Valerio; Phillips, David F; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Segransan, Damien; Sozzetti, Alessandro; Szentgyorgyi, Andrew; Watson, Chris

2014-01-01

315

Probing the Spatial Distribution of Extrasolar Planets with Gravitational Microlensing  

E-print Network

Under the current microlensing planet search strategy of monitoring events caused by stellar-mass lenses, only planets located within a narrow region of separations from central stars can be effectively detected. However, with the dramatic increase of the monitoring frequency, two additional populations of free-floating and wide-orbit planets can be detected. In this paper, we investigate the lensing properties of events caused by wide-orbit planets and find that the light curves of a significant fraction of these events will exhibit signatures of central stars, enabling one to distinguish them from those caused by free-floating planets. Due to the large primary/planet mass ratio, the effect of the central star endures to considerable separations. We find that for a Jupiter-mass planet the signatures of the central star can be detected with fractional deviations of > 5% from the best-fitting single-lens light curves for > 80% of events caused by bound planets with separations planets with separations up to 20 AU. Therefore, detecting a large sample of these events will provide useful information about the distribution of extrasolar planets around their central stars. Proper estimation of the probability of distinguishing events caused by wide-orbit planets from those caused by free-floating planets will be important for the correct determination of the frequency of free-floating planets, whose microlensing sample will be contaminated by wide-orbits planets.

Cheongho Han; Young Woon Kang

2003-03-14

316

RESOLVING THE sin(I) DEGENERACY IN LOW-MASS MULTI-PLANET SYSTEMS  

SciTech Connect

Long-term orbital evolution of multi-planet systems under tidal dissipation often converges to a stationary state, known as the tidal fixed point. The fixed point is characterized by a lack of oscillations in the eccentricities and apsidal alignment among the orbits. Quantitatively, the nature of the fixed point is dictated by mutual interactions among the planets as well as non-Keplerian effects. We show that if a roughly coplanar system hosts a hot, sub-Saturn mass planet, and is tidally relaxed, separation of planet-planet interactions and non-Keplerian effects in the equations of motion leads to a direct determination of the true masses of the planets. Consequently, a 'snap-shot' observational determination of the orbital state resolves the sin(I) degeneracy and opens up a direct avenue toward identification of the true lowest-mass exoplanets detected. We present an approximate, as well as a general, mathematical framework for computation of the line-of-sight inclination of secular systems, and apply our models illustratively to the 61 Vir system. We conclude by discussing the observability of planetary systems to which our method is applicable and we set our analysis into a broader context by presenting a current summary of the various possibilities for determining the physical properties of planets from observations of their orbital states.

Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Laughlin, Gregory, E-mail: kbatygin@gps.caltech.edu [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States)

2011-04-01

317

The Mass of Kepler-93b and The Composition of Terrestrial Planets  

NASA Astrophysics Data System (ADS)

Kepler-93b is a 1.478 ± 0.019 R ? planet with a 4.7 day period around a bright (V = 10.2), astroseismically characterized host star with a mass of 0.911 ± 0.033 M ? and a radius of 0.919 ± 0.011 R ?. Based on 86 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 32 archival Keck/HIRES observations, we present a precise mass estimate of 4.02 ± 0.68 M ?. The corresponding high density of 6.88 ± 1.18 g cm-3 is consistent with a rocky composition of primarily iron and magnesium silicate. We compare Kepler-93b to other dense planets with well-constrained parameters and find that between 1 and 6 M ?, all dense planets including the Earth and Venus are well-described by the same fixed ratio of iron to magnesium silicate. There are as of yet no examples of such planets with masses >6 M ?. All known planets in this mass regime have lower densities requiring significant fractions of volatiles or H/He gas. We also constrain the mass and period of the outer companion in the Kepler-93 system from the long-term radial velocity trend and archival adaptive optics images. As the sample of dense planets with well-constrained masses and radii continues to grow, we will be able to test whether the fixed compositional model found for the seven dense planets considered in this paper extends to the full population of 1-6 M ? planets. Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

Dressing, Courtney D.; Charbonneau, David; Dumusque, Xavier; Gettel, Sara; Pepe, Francesco; Collier Cameron, Andrew; Latham, David W.; Molinari, Emilio; Udry, Stéphane; Affer, Laura; Bonomo, Aldo S.; Buchhave, Lars A.; Cosentino, Rosario; Figueira, Pedro; Fiorenzano, Aldo F. M.; Harutyunyan, Avet; Haywood, Raphaëlle D.; Johnson, John Asher; Lopez-Morales, Mercedes; Lovis, Christophe; Malavolta, Luca; Mayor, Michel; Micela, Giusi; Motalebi, Fatemeh; Nascimbeni, Valerio; Phillips, David F.; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Szentgyorgyi, Andrew; Watson, Chris

2015-02-01

318

New strategy for planets serach in debris disks  

NASA Astrophysics Data System (ADS)

Based on the modern theory of planet formation, planetary systems are formed in protoplanetary disks that could surround young stellar and substellar objects. Giant planets formation process starts at first 100 thousand years as a consequence of disk gravitational instability. Rocky planets form later, through the coagulation of planetesimals. Common feature in both types planets formation scenarios is that once planet reaches stable orbit (especially if orbit is circular), planet clears a gap in the disk along the planet's orbit. By the debris disk stage the gap opened by planet becomes optically thin. There are two observational methods to study the structure of debris disks: with an image and via an excess in stellar spectral energy distribution (SED) at the infrared. The image of such disk is the best way to detect the gap opened by planet and even the planet itself. It is almost impossible to detect the planet around the star by studying SED, due to the big difference of their luminosities. But it is possible to suspect planet based on the param- eters of the gap cleaned by planet, that could be derived based on the analysis of SED profile. The aim of present work is to investigate a possibility to detect planet in debris disk via SED profile analyze and to determine planets physical parameters that can be derived with this method. I will present the results of numerical calculations for systems with low-mass stellar and substellar objects at 1 Gyr. Debris disk particles radii vary from 0.1 microns to 1 meter; disk masses vary from 10**-16 to 0.05 masses of the star (that initially doesn't account extinction due to the gap opened by the planet). Width of the gap opened by the planet is determined as a diameter of Hill sphere. Planet masses are varied from 10 Earth to 10 Jupiter masses. Distance from the planet to the central star is within all possible positions along the disk radius.

Zakhozhay, O.

2014-09-01

319

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

320

Direct Imaging of Multiple Planets Orbiting the Star HR 8799  

E-print Network

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; Barman, T; Zuckerman, B; Song, I; Patience, J; Lafrenière, D; Doyon, R; 10.1126/science.1166585

2008-01-01

321

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

322

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

323

GAP OPENING BY EXTREMELY LOW-MASS PLANETS IN A VISCOUS DISK  

SciTech Connect

By numerically integrating the compressible Navier-Stokes equations in two dimensions, we calculate the criterion for gap formation by a very low mass (q {approx} 10{sup -4}) protoplanet on a fixed orbit in a thin viscous disk. In contrast with some previously proposed gap-opening criteria, we find that a planet can open a gap even if the Hill radius is smaller than the disk scale height. Moreover, in the low-viscosity limit, we find no minimum mass necessary to open a gap for a planet held on a fixed orbit. In particular, a Neptune-mass planet will open a gap in a minimum mass solar nebula with suitably low viscosity ({alpha} {approx}< 10{sup -4}). We find that the mass threshold scales as the square root of viscosity in the low mass regime. This is because the gap width for critical planet masses in this regime is a fixed multiple of the scale height, not of the Hill radius of the planet.

Duffell, Paul C.; MacFadyen, Andrew I., E-mail: pcd233@nyu.edu, E-mail: macfadyen@nyu.edu [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)

2013-05-20

324

Gap Opening by Extremely Low-mass Planets in a Viscous Disk  

NASA Astrophysics Data System (ADS)

By numerically integrating the compressible Navier-Stokes equations in two dimensions, we calculate the criterion for gap formation by a very low mass (q ~ 10-4) protoplanet on a fixed orbit in a thin viscous disk. In contrast with some previously proposed gap-opening criteria, we find that a planet can open a gap even if the Hill radius is smaller than the disk scale height. Moreover, in the low-viscosity limit, we find no minimum mass necessary to open a gap for a planet held on a fixed orbit. In particular, a Neptune-mass planet will open a gap in a minimum mass solar nebula with suitably low viscosity (? <~ 10-4). We find that the mass threshold scales as the square root of viscosity in the low mass regime. This is because the gap width for critical planet masses in this regime is a fixed multiple of the scale height, not of the Hill radius of the planet.

Duffell, Paul C.; MacFadyen, Andrew I.

2013-05-01

325

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

PubMed

Planets in the habitable zone of lower-mass stars are often assumed to be in a state of tidally synchronized rotation, which would considerably affect their putative habitability. Although thermal tides cause Venus to rotate retrogradely, simple scaling arguments tend to attribute this peculiarity to the massive Venusian atmosphere. Using a global climate model, we show that even a relatively thin atmosphere can drive terrestrial planets' rotation away from synchronicity. We derive a more realistic atmospheric tide model that predicts four asynchronous equilibrium spin states, two being stable, when the amplitude of the thermal tide exceeds a threshold that is met for habitable Earth-like planets with a 1-bar atmosphere around stars more massive than ~0.5 to 0.7 solar mass. Thus, many recently discovered terrestrial planets could exhibit asynchronous spin-orbit rotation, even with a thin atmosphere. PMID:25592420

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

2015-02-01

326

Atmospheric escape by magnetically driven wind from gaseous planets  

E-print Network

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

Tanaka, Yuki A; Inutsuka, Shu-ichiro

2013-01-01

327

On The Orbital Evolution of Jupiter Mass Protoplanet Embedded in A Self-Gravity Disk  

E-print Network

We performed a series of hydro-dynamic simulations to investigate the orbital migration of a Jovian planet embedded in a proto-stellar disk. In order to take into account of the effect of the disk's self gravity, we developed and adopted an \\textbf{Antares} code which is based on a 2-D Godunov scheme to obtain the exact Reimann solution for isothermal or polytropic gas, with non-reflecting boundary conditions. Our simulations indicate that in the study of the runaway (type III) migration, it is important to carry out a fully self consistent treatment of the gravitational interaction between the disk and the embedded planet. Through a series of convergence tests, we show that adequate numerical resolution, especially within the planet's Roche lobe, critically determines the outcome of the simulations. We consider a variety of initial conditions and show that isolated, non eccentric protoplanet planets do not undergo type III migration. We attribute the difference between our and previous simulations to the contribution of a self consistent representation of the disk's self gravity. Nevertheless, type III migration cannot be completely suppressed and its onset requires finite amplitude perturbations such as that induced by planet-planet interaction. We determine the radial extent of type III migration as a function of the disk's self gravity.

Hui Zhang; Chi Yuan; D. N. C. Lin; D. C. C. Yen

2007-09-04

328

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

329

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

330

Accretion of Mass and Spin Angular Momentum by a Planet on an Eccentric Orbit  

NASA Astrophysics Data System (ADS)

We have extended our previous calculations of planetary accretion rates (Y. Greenzweig and J. J. Lissauer 1990, Icarus87, 40-77, and 1992, Icarus100, 440-463) to the case of a planet on an eccentric orbit. We have found that the dependence of accretion rates on planetary and planetesimal eccentricities can be reduced to a single parameter and that the extent of a planet's single-pass feeding zones depends (in the limit of small planetary mass) only upon the sum of the eccentricities of the planet and the planetesimals and their mutual inclination. We have also addressed the problem of the origin of planetary rotation by calculating the spin angular momentum contributed by all particles which are accreted by a planet in a uniform particle disk. Previous authors (J. J. Lissauer and D. M. Kary 1991, Icarus94, 126-159; L. Dones and S. Tremaine 1993, Icarus103, 67-92) have obtained analytic solutions for nongravitating planets on circular orbits in two-dimensional disks. We have developed new techniques which allow us to extend these calculations to the cases in which the planet's orbit is eccentric and the disk is three-dimensional. Nongravitating planets on eccentric orbits accrete the same specific rotational angular momentum as planets on circular orbits in disks of planetesimals on eccentric orbits. Planetesimal inclinations reduce the specific angular momentum accreted by nongravitating planets by 25-65%. By performing a series of numerical three-body simulations, we have found that a gravitating planet on an orbit with eccentricity e0? in a disk of planetesimals on circular orbits obtains the same rotation rate as a planet on a circular orbit in a disk of planetesimals which have e= e0. When the planet and the planetesimals are both on eccentric orbits with e? 1, the spin angular momentum is determined by the distribution of relative eccentricity vectors. If the eccentricities of the planet and planetesimals differ significantly, inclination typically acts to reduce the magnitude of the rotation rate by a few tens of percent. However, in certain cases where the eccentricities of the planet and planetesimals are comparable, inclination can change slow retrograde rotation to slow prograde rotation. A planet which accretes material primarily from the extremities of its feeding zone during the latter stage of its growth attains rapid systematic prograde rotation only if the amplitude of its epicyclic motion is comparable to or smaller than the radius of its Hill sphere.

Lissauer, Jack J.; Berman, Alice F.; Greenzweig, Yuval; Kary, David M.

1997-05-01

331

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.

2012-08-26

332

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

333

Confirmation of Earth-Mass Planets Orbiting the Millisecond Pulsar PSR B1257+12  

Microsoft Academic Search

The discovery of two Earth-mass planets orbiting an old (~10^9 years), rapidly spinning neutron star, the 6.2-millisecond radio pulsar PSR B1257+12, was announced in early 1992. It was soon pointed out that the approximately 3:2 ratio of the planets' orbital periods should lead to accurately predictable and possibly measurable gravitational perturbations of their orbits. The unambiguous detection of this effect,

Alexander Wolszczan

1994-01-01

334

Maximum-likelihood method for estimating the mass and period distributions of extrasolar planets  

Microsoft Academic Search

We investigate the distribution of mass M and orbital period P of extrasolar planets, taking account of selection effects caused by the limited velocity precision and duration of existing surveys. We fit the data on 72 planets to a power-law distribution of the form dn=CM-alphaP-beta(dM\\/M)(dP\\/P), and find alpha= 0.11 +\\/- 0.10, beta=-0.27 +\\/- 0.06 for M<~ 10 MJ, where MJ

Serge Tabachnik; Scott Tremaine

2002-01-01

335

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.

2012-08-26

336

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

337

The PLANET microlensing follow-up network: results and prospects for the detection of extra-solar planets  

NASA Astrophysics Data System (ADS)

Among various techniques to search for extra-solar planets, microlensing has some unique characteristics. Contrary to all other methods which favour nearby objects, microlensing is sensitive to planets around stars at distances of several kpc. These stars act as gravitational lenses leading to a brightening of observed luminous source stars. The lens stars that are tested for the presence of planets are not generally seen themselves. The largest sensitivity is obtained for planets at orbital separations of 1- 10 AU offering the view on an extremely interesting range with regard to our own solar system and in particular to the position of Jupiter. The microlensing signal of a jupiter-mass planet lasts typically a few days. This means that a planet reveals its existence by producing a short signal at its quasi-instantaneous position, so that planets can be detected without the need to observe a significant fraction of the orbital period. Relying on the microlensing alerts issued by several survey groups that observe ˜10 7 stars in the Galactic bulge. PLANET (Probing Lensing Anomalies NETwork) performs precise and frequent measurements on ongoing microlensing events in order to detect deviations from a light curve produced by a single point-like object. These measurements allow constraints to be put on the abundance of planets. From 42 well-sampled events between 1995 and 1999, we infer that less than 1/3 of M-dwarfs in the Galactic bulge have jupiter-mass companions at separations between 1 and 4 AU from their parent star, and that <45% have 3-jupiter-mass companions between 1 and 7 AU.

Dominik, M.; Albrow, M. D.; Beaulieu, J.-P.; Caldwell, J. A. R.; DePoy, D. L.; Gaudi, B. S.; Gould, A.; Greenhill, J.; Hill, K.; Kane, S.; Martin, R.; Menzies, J.; Naber, R. M.; Pel, J.-W.; Pogge, R. W.; Pollard, K. R.; Sackett, P. D.; Sahu, K. C.; Vermaak, P.; Watson, R.; Williams, A.

2002-03-01

338

Long-Term Observations of Stream Interaction Regions and Interplanetary Coronal Mass Ejections: Venus, Earth, and Jupiter Orbits  

NASA Astrophysics Data System (ADS)

Two types of large-scale solar wind structures, stream interaction regions (SIRs) and interplanetary coronal mass ejections (ICMEs), can drive interplanetary shocks, generate or accelerate energetic particles, and affect the planetary ionosphere and/or magnetosphere. To quantify the properties of SIRs and ICMEs at different heliocentric distances, we have identified and characterized these structures based on consistent criteria using the in situ plasma and magnetic field observations. The data sets used are Pioneer Venus Orbiter at 0.72 AU (1979 - 1988), Wind/ACE at 1 AU (1995 - 2006), and three Ulysses aphelion passes at 5.3 AU (partial 1992, 1997 - 1998, 2003 - 2005, representing slices at different phases of the solar cycle). The long-term observations enable us to study the solar cycle variations of these two structures. The parameters relevant to space weather modeling, such as the structure duration, width, maximum dynamic pressure, maximum magnetic field intensity, average speed, speed variation, and other properties of SIRs and ICMEs are all examined at each distance. ICMEs can generally affect the planetary environment more than SIRs at Venus and Earth, especially around solar maximum. However, when they propagate to 5.3 AU, some ICMEs and SIRs merge and form hybrid events at Jupiter. In general, SIRs have greater dynamic pressure, interaction strength and field intensity than ICMEs at Jupiter, and therefore they affect the space environment more than ICMEs there.

Jian, L. K.; Russell, C. T.; Luhmann, J. G.; Skoug, R. M.; Steinberg, J. T.

2009-04-01

339

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

340

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

341

Interiors of giant planets inside and outside the solar system.  

PubMed

An understanding of the structure and composition of the giant planets is rapidly evolving because of (i) high-pressure experiments with the ability to study metallic hydrogen and define the properties of its equation of state and (ii) spectroscopic and in situ measurements made by telescopes and satellites that allow an accurate determination of the chemical composition of the deep atmospheres of the giant planets. However, the total amount of heavy elements that Jupiter, Saturn, Uranus, and Neptune contain remains poorly constrained. The discovery of extrasolar giant planets with masses ranging from that of Saturn to a few times the mass of Jupiter opens up new possibilities for understanding planet composition and formation. Evolutionary models predict that gaseous extrasolar giant planets should have a variety of atmospheric temperatures and chemical compositions, but the radii are estimated to be close to that of Jupiter (between 0.9 and 1.7 Jupiter radii), provided that they contain mostly hydrogen and helium. PMID:10506563

Guillot, T

1999-10-01

342

New semi-analytic theory of the four outer planets  

Microsoft Academic Search

A planetary theory of the planets Jupiter, Saturn, Uranus and Neptune is presented. It is a classical planetary theory where the perturbations are computed in the form of Poisson series of only one angular variable. It is built with modern values of the planetary masses and fitted to the numerical integration DE245 of the Jet Propulsion Laboratory (Standish, 1994). Its

J. L. Simon

1996-01-01

343

Origin of satellite systems of the outer planets  

Microsoft Academic Search

The formation of regular satellite systems around outer planets is discussed here, with particular attention to the so-called disk phase, which links the formation of the primary body to that of the satellites. Disk models are proposed for Jupiter, Saturn and Uranus disks. The subsequent evolutive phases leading to the present satellite masses (formation of local planetesimals, collisional evolution leading

G. Magni; A. Coradini; P. Cerroni; C. Federico

1990-01-01

344

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

345

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

346

Measurement of Planet Masses with Transit Timing Variations Due to Synodic “Chopping” Effects  

NASA Astrophysics Data System (ADS)

Gravitational interactions between planets in transiting exoplanetary systems lead to variations in the times of transit that are diagnostic of the planetary masses and the dynamical state of the system. Here we show that synodic “chopping” contributions to these transit timing variations (TTVs) can be used to uniquely measure the masses of planets without full dynamical analyses involving direct integration of the equations of motion. We present simple analytic formulae for the chopping signal, which are valid (generally \\lt 10% error) for modest eccentricities e? 0.1. Importantly, these formulae primarily depend on the mass of the perturbing planet, and therefore the chopping signal can be used to break the mass/free-eccentricity degeneracy, which can appear for systems near first-order mean motion resonances. Using a harmonic analysis, we apply these TTV formulae to a number of Kepler systems, which had been previously modeled with full dynamical analyses. We show that when chopping is measured, the masses of both planets can be determined uniquely, in agreement with previous results, but without the need for numerical orbit integrations. This demonstrates how mass measurements from TTVs may primarily arise from an observable chopping signal. The formula for chopping can also be used to predict the number of transits and timing precision required for future observations, such as those made by TESS or PLATO, in order to infer planetary masses through analysis of TTVs.

Deck, Katherine M.; Agol, Eric

2015-04-01

347

Planet Applet  

NSDL National Science Digital Library

This Java applet calculates three views of the bright planets (Mercury, Venus, Mars, Jupiter, Saturn) and the Moon. It displays a diagram showing rise and set times over the year, a view at local horizon, and a view of the ecliptic plane.

Juergen Giesen

348

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

349

Extrasolar planets  

PubMed Central

The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems. PMID:11035782

Lissauer, Jack J.; Marcy, Geoffrey W.; Ida, Shigeru

2000-01-01

350

What Debris Disks Can Tell Us about the Masses, Orbits, and Compositions of Planets  

NASA Astrophysics Data System (ADS)

Our solar system contains four gas giant planets that have interacted and shaped the Kuiper Belt since their formation. They have affected its structure and shape and in the process have flung comets and small rocky bodies towards the inner terrestrial planets. Many of these bodies contain organic materials and water ice, the main ingredients required for Earth-like life. Therefore the Kuiper Belt holds clues to the properties of the solar system's planets. In the same way, it is thought that extrasolar debris disks, analogous to the solar system's Kuiper Belt, contain information on nearby planets. In this talk, I will discuss several recent results that relate the properties of debris disks to masses, orbits, and compositions of as-yet undetected planets. First, I will present 3.8 micron LBTI high-contrast adaptive optics (AO) imaging on the bright, edge-on debris disk around HD 32297 (Rodigas et al. 2014b). Combing our high signal-to-noise (S/N) detection with archival images at 1-2 microns, we constrain the composition of the dust grains in the disk. In particular, we test a recently proposed cometary grains model. We find that pure water ice is a better overall fit, suggesting at least one of the key ingredients for life may be present in this system. Second, I will present Magellan AO (MagAO) imaging results on the debris ring around HR 4796A at seven wavelengths from 0.7-4 microns (Rodigas et al. 2014c, in prep.). With such complete wavelength coverage and high S/N detections, we are able to obtain accurate photometry and constrain the composition of the dustÑin particular with regard to organic materials. Finally, I will present a new tool designed specifically for observers and planet hunters. Using a simple equation that depends solely on the width of a debris disk in scattered light, observers can estimate the maximum mass of an interior planet shepherding the disk (Rodigas et al. 2014a). This provides an independent, dynamical check on an imaged planet's mass, which can be very uncertain. The planet's minimum semimajor axis and eccentricity can also be calculated. In general, more massive planets create broader debris rings, meaning observers should target wider debris disks while searching for planets.

Rodigas, T.

2014-09-01

351

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

E-print Network

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

Leconte, Jérémy; Menou, Kristen; Murray, Norman

2015-01-01

352

Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets  

NASA Astrophysics Data System (ADS)

The Kepler space telescope has proven capable of detecting transits of objects almost as small as the Earth's Moon. Some studies suggest that moons as small as 0.2 Earth masses can be detected in the Kepler data by transit timing variations and transit duration variations of their host planets. If such massive moons exist around giant planets in the stellar habitable zone (HZ), then they could serve as habitats for extraterrestrial life. While earlier studies on exomoon habitability assumed the host planet to be in thermal equilibrium with the absorbed stellar flux, we here extend this concept by including the planetary luminosity from evolutionary shrinking. Our aim is to assess the danger of exomoons to be in a runaway greenhouse state due to extensive heating from the planet. We apply pre-computed evolution tracks for giant planets to calculate the incident planetary radiation on the moon as a function of time. Added to the stellar flux, the total illumination yields constraints on a moon's habitability. Ultimately, we include tidal heating to evaluate a moon's energy budget. We use a semi-analytical formula to parameterize the critical flux for the moon to experience a runaway greenhouse effect. Planetary illumination from a 13-Jupiter-mass planet onto an Earth-sized moon at a distance of ten Jupiter radii can drive a runaway greenhouse state on the moon for about 200 million years (Myr). When stellar illumination equivalent to that received by Earth from the Sun is added, then the runaway greenhouse holds for about 500 Myr. After 1000 Myr, the planet's habitable edge has moved inward to about six Jupiter radii. Exomoons in orbits with eccentricities of 0.1 experience strong tidal heating; they must orbit a 13-Jupiter-mass host beyond 29 or 18 Jupiter radii after 100 Myr (at the inner and outer boundaries of the stellar HZ, respectively), and beyond 13 Jupiter radii (in both cases) after 1000 Myr to be habitable. If a roughly Earth-sized, Earth-mass moon would be detected in orbit around a giant planet, and if the planet-moon duet would orbit in the stellar HZ, then it will be crucial to recover the orbital history of the moon. If, for example, such a moon around a 13-Jupiter-mass planet has been closer than 20 Jupiter radii to its host during the first few hundred million years at least, then it might have lost substantial amounts of its initial water reservoir and be uninhabitable today.

Heller, R.; Barnes, R.; Barnes

2015-04-01

353

A CORRELATION BETWEEN STELLAR ACTIVITY AND THE SURFACE GRAVITY OF HOT JUPITERS  

SciTech Connect

Recently, Knutson et al. have demonstrated a correlation between the presence of temperature inversions in the atmospheres of hot Jupiters and the chromospheric activity levels of the host stars. Here, we show that there is also a correlation, with greater than 99.5% confidence, between the surface gravity of hot Jupiters and the activity levels of the host stars, such that high surface gravity planets tend be found around high-activity stars. We also find a less significant positive correlation between planet mass and chromospheric activity, but no significant correlation is seen between planet radius and chromospheric activity. We consider the possibility that this may be due to an observational bias against detecting lower mass planets around higher activity stars, but conclude that this bias is only likely to affect the detection of planets much smaller than those considered here. Finally, we speculate on physical origins for the correlation-including the possibility that the effect of stellar insolation on planetary radii has been significantly underestimated, that strong UV flux evaporates planetary atmospheres, or that high-mass hot Jupiters induce activity in their host stars-but do not find any of these hypotheses to be particularly compelling.

Hartman, J. D., E-mail: jhartman@cfa.harvard.ed [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2010-07-10

354

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

355

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

356

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

357

The Sun, eight planets and three dwarf planets  

E-print Network

of our solar system. The planets all revolve around this extremely hot, giant ball of burning gas- beesthoek near Johannesburg. Some people believe that humans will be ]able to live on Mars some time. JUPITER Jupiter is the largest planet in our solar system, made mostly of gas and liquid. The giant red

Jarrett, Thomas H.

358

On Jupiter's inertial mode oscillations  

E-print Network

Properties of inertial modes of Jupiter are investigated for an n=1 polytropic description of the planet interior. We use the anelastic approximation to overcome the usual handicap of a severe spherical harmonics truncation. A powerful iterative solver then allows us to compute the frequencies of the most promising low-order modes using as many spherical harmonics as necessary. The induced O(1%) errors of our model are now within observational limits. A plausible seismological model of Jupiter might thus be at hand provided the use of a more realistic description of the planet interior.

Boris Dintrans; Rachid Ouyed

2001-08-31

359

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

2004-09-15

360

KEPLER-6b: A TRANSITING HOT JUPITER ORBITING A METAL-RICH STAR  

SciTech Connect

We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H]= +0.34{+-}0.04. The planet's mass is about 2/3 that of Jupiter, M {sub P} = 0.67 M {sub J}, and the radius is 30% larger than that of Jupiter, R {sub P} = 1.32 R {sub J}, resulting in a density of {rho}{sub P} = 0.35 g cm{sup -3}, a fairly typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, M {sub *} = 1.21 M {sub sun}, and larger than the Sun, R {sub *} = 1.39 R {sub sun}.

Dunham, Edward W. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Borucki, William J.; Koch, David G.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [San Jose State University, San Jose, CA 95192 (United States); Buchhave, Lars A.; Furesz, Gabor; Geary, John C.; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Caldwell, Douglas A.; Jenkins, Jon M. [SETI Institute, Mountain View, CA 94043 (United States); Cochran, William D.; Endl, Michael [University of Texas, Austin, TX 78712 (United States); Fischer, Debra [Yale University, New Haven, CT 06510 (United States); Gautier, Thomas N. [Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109 (United States); Gilliland, Ronald L. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Gould, Alan [Lawrence Hall of Science, Berkeley, CA 94720 (United States); Howell, Steve B. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Kjeldsen, Hans [University of Aarhus, Aarhus (Denmark)] (and others)

2010-04-20

361

ExtraSolar Planets Finding Extrasolar Planets. I  

E-print Network

ExtraSolar Planets #12;Finding Extrasolar Planets. I Direct Searches Direct searches are difficult #12;Finding Extrasolar Planets. II Transits #12;Transits Transits requires an edge-on orbit. ·Jupiter;How Transits Work #12;Finding Extrasolar Planets. III Astrometric Wobble #12;Finding Extrasolar

Walter, Frederick M.

362

New Horizons At Jupiter: Overview Of Results  

Microsoft Academic Search

NASA's New Horizons spacecraft has provided new data on the Jupiter system, acquiring new perspectives of the giant planet's atmosphere, rings, moons and magnetosphere. These new views include the closest look yet at the Earth-sized \\

J. M. Moore

2007-01-01

363

Stimulation of Jupiter's Radio Emission by Io  

Microsoft Academic Search

Variations in the decameter radio signals from Jupiter are known to be associated with one of the planet's five satellites. It is now suggested that Io travels in the analogue of the inner Van Allen radiation belt surrounding Jupiter, giving rise to a plasma wake which streams ahead of it by about 130,000 km and stimulates the radio emission from

L. Marshall; W. F. Libby

1967-01-01

364

Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass Stars  

E-print Network

Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our Solar System. Here we suggest that the water content of primitive bodies in many planetary systems may actually be much higher, as carbonaceous chondrites have lost some of their original water due to heating from short-lived radioisotopes that drove parent body alteration. Using N-body simulations, we explore how planetary accretion would be different if bodies beyond the water line contained a water mass fraction consistent with chemical equilibrium calculations, and more similar to comets, as opposed to the more traditional water-depleted values. We apply this model to consider planet formation around stars of different masses and identify trends in the properties of Habitable Zone planets and planetary system architecture which could be tested by ongoing exoplanet census data collection. Comparison of such data with the model predicted tren...

Ciesla, Fred J; Pascucci, Ilaria; Apai, Daniel

2015-01-01

365

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

366

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

367

Jupiter: Giant of the solar system. [its solar orbits  

NASA Technical Reports Server (NTRS)

Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

1975-01-01

368

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

369

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

370

Reflected Spectra and Albedos of Extrasolar Giant Planets. I. Clear and Cloudy Atmospheres  

Microsoft Academic Search

The reflected spectra of extrasolar giant planets are primarily influenced by Rayleigh scattering, molecular absorption, and atmospheric condensates. We present model geometric albedo and phase-integral spectra and Bond albedos for planets and brown dwarfs with masses between 0.8 and 70 Jupiter masses. Rayleigh scattering predominates in the blue while molecular absorption removes most red and infrared photons. Thus cloud-free atmospheres,

Mark S. Marley; Christopher Gelino; Denise Stephens; Jonathan I. Lunine; Richard Freedman

1999-01-01

371

Terrestrials Dwarf Planets  

E-print Network

Terrestrials Gas Giants Ice Giants Dwarf Planets The Solar System #12;Neptune Uranus Saturn Jupiter Density: 3900 ­ 5500 kg m-3 #12;Jupiter 318 ME 5.2 AU Uranus 15 ME 19.6 AUSaturn 95 ME 9.5 AU Neptune 17 3.88 RE Uranus Neptune Uranus and Neptune are Ice Giants made mostly of ices with thin Hydrogen

Gaudi, B. Scott

372

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

373

EVIDENCE FOR THE TIDAL DESTRUCTION OF HOT JUPITERS BY SUBGIANT STARS  

SciTech Connect

Tidal transfer of angular momentum is expected to cause hot Jupiters to spiral into their host stars. Although the timescale for orbital decay is very uncertain, it should be faster for systems with larger and more evolved stars. Indeed, it is well established that hot Jupiters are found less frequently around subgiant stars than around main-sequence stars. However, the interpretation of this finding has been ambiguous, because the subgiants are also thought to be more massive than the F- and G-type stars that dominate the main-sequence sample. Consequently, it has been unclear whether the absence of hot Jupiters is due to tidal destruction or inhibited formation of those planets around massive stars. Here we show that the Galactic space motions of the planet-hosting subgiant stars demand that on average they be similar in mass to the planet-hosting main-sequence F- and G-type stars. Therefore the two samples are likely to differ only in age, and provide a glimpse of the same exoplanet population both before and after tidal evolution. As a result, the lack of hot Jupiters orbiting subgiants is clear evidence for their tidal destruction. Questions remain, though, about the interpretation of other reported differences between the planet populations around subgiants and main-sequence stars, such as their period and eccentricity distributions and overall occurrence rates.

Schlaufman, Kevin C.; Winn, Joshua N., E-mail: kschlauf@mit.edu, E-mail: jwinn@mit.edu [Physics Department, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2013-08-01

374

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

Microsoft Academic Search

We report precise Doppler measurements of GJ 436 (M2.5 V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 days, eccentricity of 0.12 (consistent with zero), and velocity semiamplitude of K=18.1 m s-1. The minimum mass (Msini) for the planet is 0.067MJup=1.2MNep=21MEarth, making it the lowest mass exoplanet yet found around a main-sequence star

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

2004-01-01

375

MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU  

SciTech Connect

We demonstrate that the observed distribution of 'hot Neptune'/'super-Earth' systems is well reproduced by a model in which planet assembly occurs in situ, with no significant migration post-assembly. This is achieved only if the amount of mass in rocky material is {approx}50-100 M{sub Circled-Plus} interior to 1 AU. Such a reservoir of material implies that significant radial migration of solid material takes place, and that it occurs before the stage of final planet assembly. The model not only reproduces the general distribution of mass versus period but also the detailed statistics of multiple planet systems in the sample. We furthermore demonstrate that cores of this size are also likely to meet the criterion to gravitationally capture gas from the nebula, although accretion is rapidly limited by the opening of gaps in the gas disk. If the mass growth is limited by this tidal truncation, then the scenario sketched here naturally produces Neptune-mass objects with substantial components of both rock and gas, as is observed. The quantitative expectations of this scenario are that most planets in the 'hot Neptune/super-Earth' class inhabit multiple-planet systems, with characteristic orbital spacings. The model also provides a natural division into gas-rich (hot Neptune) and gas-poor (super-Earth) classes at fixed period. The dividing mass ranges from {approx}3 M{sub Circled-Plus} at 10 day orbital periods to {approx}10 M{sub Circled-Plus} at 100 day orbital periods. For orbital periods <10 days, the division is less clear because a gas atmosphere may be significantly eroded by stellar radiation.

Hansen, Brad M. S. [Department of Physics and Astronomy and Institute of Geophysics and Planetary Physics, University of California Los Angeles, Los Angeles, CA 90095 (United States); Murray, Norm, E-mail: hansen@astro.ucla.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, Ontario (Canada)

2012-06-01

376

Planet Formation is Unlikely in Equal-Mass Binary Systems with A ~ 50 AU  

NASA Astrophysics Data System (ADS)

We show that planet formation via both gravitational collapse and core accretion is unlikely to occur in equal-mass binary systems with moderate (~50 AU) semimajor axes. Internal thermal energy generation in the disks is sufficient to heat the gas everywhere so that spiral structures quickly decay rather than grow or fragment. This same heating will inhibit dust coagulation because the temperatures rise above the vaporization temperatures of many volatile materials. We consider other processes not included in the model and conclude that our temperatures are conservatively estimated (low), i.e., planet formation is less likely in real systems than in the model.

Nelson, Andrew F.

2000-07-01

377

Jupiter and Three Galilean Satellites  

NASA Technical Reports Server (NTRS)

Jupiter, its Great Red Spot and three of its four largest satellites are visible in this photo taken Feb. 5, 1979, by Voyager 1. The spacecraft was 28.4 million kilometers (17.5 million miles) from the planet at the time. The innermost large satellite, Io, can be seen against Jupiter's disk. Io is distinguished by its bright, brown-yellow surface. To the right of Jupiter is the satellite Europa, also very bright but with fainter surface markings. The darkest satellite, Callisto (still nearly twice as bright as Earth's Moon), is barely visible at the bottom left of the picture. Callisto shows a bright patch in its northern hemisphere. All three orbit Jupiter in the equatorial plane, and appear in their present position because Voyager is above the plane. All three satellites show the same face to Jupiter always -- just as Earth's Moon always shows us the same face. In this photo we see the sides of the satellites that always face away from the planet. Jupiter's colorfully banded atmosphere displays complex patterns highlighted by the Great Red Spot, a large, circulating atmospheric disturbance. This photo was assembled from three black and white negatives by the Image Processing Lab at Jet Propulsion Laboratory. JPL manages and controls the Voyager project for NASA's Office of Space Science.

1979-01-01

378

Terrestrial planet formation from a truncated disk -- The 'Grand Tack'  

NASA Astrophysics Data System (ADS)

A new terrestrial planet formation model (Walsh et al., 2011) explores the effects of a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation (Masset & Snellgrove 2001, Morbidelli & Crida 2007, Pierens & Nelson 2008, Pierens & Raymond 2011). The inward migration of Jupiter truncates the disk of planetesimals and embryos in the terrestrial planet region. Subsequent accretion in that region then forms the terrestrial planets, in particular it produces the correct Earth/Mars mass ratio, which has been difficult to reproduce in simulations with a self-consistent set of initial conditions (see, eg. Raymond et al. 2009, Hansen 2009). Additionally, the outward migration of the giant planets populates the asteroid belt with distinct populations of bodies, with the inner belt filled by bodies originating inside of 3 AU, and the outer belt filled with bodies originating from beyond the giant planets. This differs from previous models of terrestrial planet formation due to the early radial mixing of material due to the giant planet's substantial migration. Specifically, the assumption that the current radial distribution of material in the inner Solar System is reflective of the primordial distribution of material in that region is no longer necessary. We will discuss the implications of this model in relation to previous models of terrestrial planet formation as well as available chemical and isotopic constraints.

Walsh, K. J.; Morbidelli, A.; Raymond, S.; O'Brien, D. P.; Mandell, A. M.

2012-12-01

379

Barnard’s Star: Planets or Pretense  

NASA Astrophysics Data System (ADS)

Barnard’s Star remains popular with planet hunters because it is not only an extremely near, high proper motion star, but also the object of early planet-detection claims. In 1963, van de Kamp explained perturbations in its proper motion by the presence of a planet. In 1969, he produced another single-planet solution and a two-planet solution to the astrometric wobbles detected. At least 19 studies have failed to confirm his results using a range of techniques, including radial velocity, direct imaging, and speckle interferometry. However, most of them lacked the sensitivity to detect the planets he described, including astrometric studies at the McCormick and Naval Observatories. However, radial-velocity monitoring of Barnard’s Star at Lick and Keck Observatories from 1987 through 2012 appears to have ruled out such planets. Based upon observations made at the Sproul Observatory between 1916 and 1962, van de Kamp claimed that Barnard’s Star had a planet with about 1.6 times the mass of Jupiter and an orbital period of 24 years. After accounting for instrumentation effects that might have been partially responsible for his initial results, he continued to assert that this red dwarf had two planets. In his 1982 analysis of ~20,000 exposures collected between 1938 and 1981, he calculated that two planets with 0.7- and 0.5-Jupiter masses in 12- and 20-year orbits, respectively, orbited the second-closest stellar system to our own. Starting in 1995, the dramatic successes of radial velocity searches for extrasolar planets drove van de Kamp’s unsubstantiated claims from popular consciousness. Although many low-mass stellar companions were discovered through astrometry, the technique has been less successful for planets: “The Extrasolar Planets Encyclopaedia” identifies one such discovery out of the 997 planets listed on 2013 September 23. Although Barnard’s Star has lost its pretensions to hosting the first extrasolar planets known, its intrinsic properties will keep it under observation. NSF grant AST 98-20711, Litton Marine Systems, Levinson Fund, University of Virginia, Hampden-Sydney College, and US Naval Observatory supported this research.

Bartlett, Jennifer L.; Ianna, P. A.

2014-01-01

380

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

381

Voyager picture of Jupiter  

NASA Technical Reports Server (NTRS)

NASA's Voyager 1 took this picture of the planet Jupiter on Saturday, Jan. 6, the first in its three-month-long, close-up investigation of the largest planet. The spacecraft, flying toward a March 5 closest approach, was 35.8 million miles (57.6 million kilometers) from Jupiter and 371.7 million miles (598.2 million kilometers) from Earth when the picture was taken. As the Voyager cameras begin their meteorological surveillance of Jupiter, they reveal a dynamic atmosphere with more convective structure than had previously been thought. While the smallest atmospheric features seen in this picture are still as large as 600 miles (1,000 kilometers) across, Voyager will be able to detect individual storm systems as small as 3 miles (5 kilometers) at closest approach. The Great Red Spot can be seen near the limb at the far right. Most of the other features are too small to be seen in terrestrial telescopes. This picture was transmitted to the Jet Propulsion Laboratory through the Deep Space Network's tracking station at Madrid, Spain. The Voyager Project is managed for NASA by Caltech's Jet Propulsion Laboratory.

1998-01-01

382

Pioneer F mission to Jupiter  

NASA Technical Reports Server (NTRS)

The experimental designs for the Pioneer F mission to Jupiter are described. The spacecraft is designed to make measurements of the planet's atmosphere, radiation belts, heat balance, magnetic fields, moons, and other related phenomena. The mission also characterizes the heliosphere, the interstellar gas, cosmic rays, asteroids, and meteoroids between the earth and 2.4 billion kilometers from the sun.

Allaway, H. G.; Waller, P. W.

1972-01-01