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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

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

3

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.

4

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

5

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.

6

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.

7

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

8

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

SciTech Connect

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

Buchhave, L. A.; Bakos, G. A.; Hartman, J. D.; Torres, G.; Latham, D. W.; Noyes, R. W.; Esquerdo, G. A.; Beky, B.; Sasselov, D. D.; Furesz, G.; Quinn, S. N.; Stefanik, R. P.; Szklenar, T. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Andersen, J. [Niels Bohr Institute, Copenhagen University (Denmark); Kovacs, G. [Konkoly Observatory, Budapest (Hungary); Shporer, A. [Las Cumbres Observatory Global Telescope Network, Goleta, CA (United States); Fischer, D. A. [Department of Astronomy, Yale University, New Haven, CT (United States); Johnson, J. A. [Department of Astrophysics, California Institute of Technology, Pasadena, CA (United States); Marcy, G. W.; Howard, A. W. [Department of Astronomy, University of California, Berkeley, CA (United States)

2011-06-01

9

Multiple-Planet Scattering and the Origin of Hot Jupiters  

Microsoft Academic Search

Exoplanets show a pile-up of Jupiter-size planets in orbits with a 3-day period. A fraction of these hot Jupiters have retrograde orbits with respect to the parent star's rotation. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization. We considered planetary systems having 3 and 4 planets initially. We found

C. Beauge; D. Nesvorny

2011-01-01

10

Jupiter-sized Planets in the Solar System and Elsewhere  

Microsoft Academic Search

The discovery of the first extrasolar planet, 51 Pegasi, in 1995 has opened up a new and exciting area of planetary astronomy.\\u000a Using a number of different techniques 170 extrasolar planets have now been discovered, and this number is rapidly increasing.\\u000a Due partly to observational biases, just over half of these newly discovered planets are ‘Hot Jupiters’ — Jupiter sized

Patrick G. J. Irwin

11

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

12

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.

13

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

14

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

NASA Astrophysics Data System (ADS)

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

15

Planets and Axisymmetric Mass Loss  

E-print Network

Bipolar planetary nebulae (PNe), as well as extreme elliptical PNe are formed through the influence of a stellar companion. But half of all PN progenitors are not influenced by any stellar companion, and, as I show here, are expected to rotate very slowly on reaching the upper asymptotic giant branch; hence they expect to form spherical PNe, unless they are spun-up. But since most PNe are not spherical, I argue that about 50 percents of AGB stars are spun-up by planets, even planets having a mass as low as 0.01 times the mass of Jupiter, so they form elliptical PNe. The rotation by itself will not deform the AGB wind, but may trigger another process that will lead to axisymmetric mass loss, e.g., weak magnetic activity, as in the cool magnetic spots model. This model also explains the transition from spherical to axisymmetric mass loss on the upper AGB. For such low mass planets to substantially spin-up the stellar envelope, they should enter the envelope when the star reaches the upper AGB. This "fine-tuning" can be avoided if there are several planets on average around each star, as is the case in the solar system, so that one of them is engulfed when the star reaches the upper AGB.

Noam Soker

2000-10-12

16

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

E-print Network

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

17

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.

18

Analyzing Mass Loss and Tidal Circularization as a Source for Sustained Eccentric Orbits in Hot Jupiters  

NASA Astrophysics Data System (ADS)

As the number of extrasolar planets and planet candidates increases, so does the number of systems that look strikingly different from our own. Hot Jupiters are such a system and are characterized by a Jupiter mass planet with a close-in orbit. Because of the proximity of the planet to its parent star, we would expect these systems to be tidally circularized. However, we observe many with significant eccentricities, suggesting that a mechanism must exist to account for sustained eccentric orbits. Previous analyses found that, in a population of eccentric hot Jupiters generated by planet-planet scattering, a significant fraction will overfill their Roche lobe at periastron. Other work has noted that mass loss in systems similar to hot Jupiters can act to increase the eccentricity of the orbit of a binary system. Here, we consider the effects of tidal circularization and mass loss on the orbital evolution of the hot Jupiters. By analyzing the balance between the tidal circularization and mass loss, we can determine an equilibrium eccentricity as a function of planet mass and the tidal quality factor, Q. If such an equilibrium value exists, then it is possible for this mechanism to be responsible for the sustained eccentric orbits of hot Jupiters that we observe. We present the orbital parameters for these equilibrium orbits over a broad parameter space and compare those results to the current population of observed extrasolar planets.

Salmon, Rachel L.; Sepinsky, Jeremy F.

2015-01-01

19

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

20

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

21

Study of the Universe via Planets Phenomena: Jupiter contribution  

NASA Astrophysics Data System (ADS)

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

Cocchiara, C. M.

2011-10-01

22

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

E-print Network

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 M$_{\\rm Jup}$, 1.06 R$_{\\rm Jup}$) in a 3.868-d period around an active mid-K dwarf. We estimate a stellar age of 1 Gyr from both gyrochronological and age-activity relations, though an alternative gyrochronological relation suggests an age of 3 Gyr. ROSAT detected X-rays at a distance of 60$\\pm$27 arcsec from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ~10$^{12}$ g s$^{-1}$. This is 1-2 orders of magnitude higher than the evaporation rate estimated for HD 209458b and HD 189733b, both of which have exhibited anomalously-large Lyman-{\\alpha} absorption during transit. WASP-70Ab is a sub-Jupiter-mass planet (0.59 M$_{\\rm Jup}$, 1.16R$_{\\rm Jup}$) in a 3.713-d orbit around the primary of a spatially-resolved G4+K3 binary, with a separation of 3.3 arcsec ($\\geq$800 AU). We exploit the binar...

Anderson, D R; Delrez, L; Doyle, A P; Faedi, F; Fumel, A; Gillon, M; Chew, Y Gómez Maqueo; 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

2013-01-01

23

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.

24

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

25

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

26

Open Cluster Planets and an Observational Constraint on Hot Jupiter Migration  

NASA Astrophysics Data System (ADS)

In the absence of a third body, the orbits of short period giant planets should circularize due to tidal forces from their host stars. However, the youngest and most distant hot Jupiters may have circularization timescales larger than the age of the system. These "dynamically young" planets would not have had time to tidally circularize. If hot Jupiters form primarily through Type II migration, which is expected to preserve circular orbits, then both dynamically young and old planets should be found on circular orbits. On the other hand, if the migration process can impart significant eccentricity, as is the case for planet-planet scattering, there should be an observable difference between the eccentricity distributions of dynamically young and dynamically old hot Jupiters. We use our discovery of the eccentric Hyades planet HD285507b to highlight this analysis and conclude that planet-planet scattering plays an important role in hot Jupiter migration.

Quinn, Samuel N.; White, R. J.; Latham, D. W.; Buchhave, L. A.; Torres, G.; Stefanik, R. P.

2014-01-01

27

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

28

Final state of thermal evolution of Jupiter-type planet  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

29

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

30

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

31

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

32

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

33

Formation of Terrestrial Planets in a Dissipating Gas Disk with Jupiter and Saturn  

Microsoft Academic Search

We have performed N body simulation on formation of terrestrial planets, including the effect of dynamical friction of gas disk. Jupiter and Saturn are also included in the integrations to see the effect of gas giant planets. Terrestrial planets are formed through coagulation of protoplanets which are about the size of Mars. Their orbits are almost circular when they are

J. Kominami; S. Ida

2003-01-01

34

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

35

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

36

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

37

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

38

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

39

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

40

Hot Nights on Extrasolar Planets: Mid-IR Phase Variations of Hot Jupiters  

E-print Network

We present results from Spitzer Space Telescope observations of the mid-infrared phase variations of three short-period extrasolar planetary systems: HD 209458, HD 179949 and 51 Peg. We gathered IRAC images in multiple wavebands at eight phases of each planet's orbit. We find the uncertainty in relative photometry from one epoch to the next to be significantly larger than the photon counting error at 3.6 micron and 4.5 micron. We are able to place 2-sigma upper limits of only 2% on the phase variations at these wavelengths. At 8 micron the epoch-to-epoch systematic uncertainty is comparable to the photon counting noise and we detect a phase function for HD 179949 which is in phase with the planet's orbit and with a relative peak-to-trough amplitude of 0.00141(33). Assuming that HD 179949b has a radius R_J < R_p < 1.2R_J, it must recirculate less than 21% of incident stellar energy to its night side at the 1-sigma level (where 50% signifies full recirculation). If the planet has a small Bond albedo, it must have a mass less than 2.4 M_J (1-sigma). We do not detect phase variations for the other two systems but we do place the following 2-sigma upper limits: 0.0007 for 51 Peg, and 0.0015 for HD 209458. Due to its edge-on configuration, the upper limit for HD 209458 translates, with appropriate assumptions about Bond albedo, into a lower limit on the recirculation occuring in the planet's atmosphere. HD 209458b must recirculate at least 32% of incident stellar energy to its night side, at the 1-sigma level, which is consistent with other constraints on recirculation from the depth of secondary eclipse depth at 8 micron and the low optical albedo. These data indicate that different Hot Jupiter planets may experience different recirculation efficiencies.

N. B. Cowan; E. Agol; D. Charbonneau

2007-06-19

41

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

42

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

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

43

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

44

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

45

WASP16b: A New Jupiter-Like Planet Transiting a Southern Solar Analog  

Microsoft Academic Search

We report the discovery from WASP-South of a new Jupiter-like extrasolar planet, WASP-16b, which transits its solar analog host star every 3.12 days. Analysis of the transit photometry and radial velocity spectroscopic data leads to a planet with R p = 1.008 ± 0.071 R Jup and M p = 0.855 ± 0.059 M Jup, orbiting a host star with

T. A. Lister; D. R. Anderson; M. Gillon; L. Hebb; B. S. Smalley; A. H. M. J. Triaud; A. Collier Cameron; D. M. Wilson; R. G. West; S. J. Bentley; D. J. Christian; R. Enoch; C. A. Haswell; C. Hellier; K. Horne; J. Irwin; Y. C. Joshi; S. R. Kane; M. Mayor; P. F. L. Maxted; A. J. Norton; N. Parley; F. Pepe; D. Pollacco; D. Queloz; R. Ryans; D. Segransan; I. Skillen; I. Todd; S. Udry; P. J. Wheatley

2009-01-01

46

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

47

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?

48

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

49

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

50

A Mass Function Constraint on Extrasolar Giant Planet Evaporation Rates  

E-print Network

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

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

2007-02-09

51

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

E-print Network

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

Gregory Laughlin; Peter Bodenheimer; Fred C. Adams

2004-07-15

52

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

Microsoft Academic Search

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

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

1992-01-01

53

Formation of multiple terrestrial planets under the influence of a hot Jupiter  

NASA Astrophysics Data System (ADS)

According to the hybrid scenario of planet formation (Inutsuka 2009), giant planets can initially form via gravitational instability in a protoplanetary disk, and subsequently terrestrial planets grow on the basis of the core accretion model. In this work, we investigate formation of close-in terrestrial planets from planetary embryos under the influence of a hot Jupiter (HJ) using gravitational N-body simulations that include gravitational interactions between the gas disk and the planet (e.g., type I migration). We find that several planets are formed and captured in mutual mean motion resonances outside the edge of the gap in the disk, which is opened up by the HJ. The innermost planet is also in the 2:1 resonance with the HJ and thus gravitationally interact with each other, leading to inward migration of the HJ. The migration timescale of the HJ depends on the solid amount in the disk; the HJ does not exhibit inward migration in the result of decreased solid density. We can give several possible explanations for the origin of properties of observed close-in exoplanet systems; we propose two possibilities for the lack of companion planets in HJ systems.

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

2013-07-01

54

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

55

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

56

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

57

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.

58

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

59

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

E-print Network

We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R_PL = 10.12 \\pm 0.56 R_E) 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 three 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 Neptune to Jupiter. These detections nearly double the number of gas giant planet candidates orbiting at habitable zone distances. We conducted spectroscopic observat...

Wang, Ji; 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; Giguere, Matthew J; Brewer, John M; Lynn, Stuart; Simpson, Robert; Hoekstra, Abe J; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Chopin, Mike

2013-01-01

60

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

61

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

62

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

63

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.

Institute, Lunar A.; Nasa

2011-01-01

64

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

65

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

E-print Network

Aims. Hot Jupiters are thought to belong to single-planet systems. Somewhat surprisingly, about one quarter of hot Jupiters were reported to exhibit Transit Timing Variations (TTVs). The aim of this paper is to identify the origin of this observation. Methods. We present TTV frequencies and amplitudes of hot Jupiters in Kepler Q0--6 data with Fourier analysis. Results. We identified 29 systems with TTV above 4-sigma confidence, about half of them exhibiting multiple TTV frequencies. Thirteen of these objects (HAT-P-7b, KOI-13, 127, 188, 196, 203, 225, 254, 428, 607, 774, 897, 1176) likely show TTVs due to a systematic observational effect: long cadence data sampling is regularly shifted transit-by-transit, interacting with the transit light curves and introducing a periodic bias. In case of other systems, the activity and rotation of the host star can modulate light curves and explain the observed TTVs. After excluding the systems that were inadequately sampled or showed signs of stellar rotation, we ended up...

Szabó, R; Dálya, G

2012-01-01

66

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

67

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

E-print Network

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

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

2015-01-01

68

The lowest mass giant planet ever imaged around a star  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

69

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

70

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

71

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

72

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

73

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

74

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

75

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

76

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

77

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

NASA Astrophysics Data System (ADS)

Using the WASP transit survey, we report the discovery of three new hot Jupiters, WASP-68 b, WASP-73 b and WASP-88 b. The planet WASP-68 bhas a mass of 0.95 ± 0.03 MJup, a radius of 1.24-0.06+0.10 RJup, and orbits a V = 10.7 G0-type star (1.24 ± 0.03 M? 1.69-0.06+0.11 R?, Teff = 5911 ± 60 K) with a period of 5.084298 ± 0.000015 days. Its size is typical of hot Jupiters with similar masses. The planet WASP-73 bis significantly more massive (1.88-0.06+0.07 MJup) and slightly larger (1.16-0.08+0.12 RJup) than Jupiter. It orbits a V = 10.5 F9-type star (1.34-0.04+0.05 M?, 2.07-0.08+0.19 R?, Teff = 6036 ± 120 K) every 4.08722 ± 0.00022 days. Despite its high irradiation (~2.3 × 109 erg s-1 cm-2), WASP-73 b has a high mean density (1.20-0.30+0.26 ?Jup) that suggests an enrichment of the planet in heavy elements. The planet WASP-88 bis a 0.56 ± 0.08 MJuphot Jupiter orbiting a V = 11.4 F6-type star (1.45 ± 0.05 M?, 2.08-0.06+0.12 R?, Teff = 6431 ± 130 K) with a period of 4.954000 ± 0.000019 days. With a radius of 1.70-0.07+0.13 RJup, it joins the handful of planets with super-inflated radii. The ranges of ages we determine through stellar evolution modeling are 4.5-7.0 Gyr for WASP-68, 2.8-5.7 Gyr for WASP-73 and 1.8-4.3 Gyr for WASP-88. The star WASP-73 appears to be significantly evolved, close to or already in the subgiant phase. The stars WASP-68 and WASP-88 are less evolved, although in an advanced stage of core H-burning. Tables 1-3 are available in electronic form at http://www.aanda.orgThe photometric time-series used in this work are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/563/A143

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

2014-03-01

78

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

79

WASP-16b: A NEW JUPITER-LIKE PLANET TRANSITING A SOUTHERN SOLAR ANALOG  

SciTech Connect

We report the discovery from WASP-South of a new Jupiter-like extrasolar planet, WASP-16b, which transits its solar analog host star every 3.12 days. Analysis of the transit photometry and radial velocity spectroscopic data leads to a planet with R{sub p} = 1.008 +- 0.071 R{sub Jup} and M{sub p} = 0.855 +- 0.059 M{sub Jup}, orbiting a host star with R {sub *} = 0.946 +- 0.054 R{sub sun} and M{sub *} = 1.022 +- 0.101 M{sub sun}. Comparison of the high resolution stellar spectrum with synthetic spectra and stellar evolution models indicates the host star is a near-solar metallicity ([Fe/H] =0.01 +- 0.10) solar analog (T{sub eff} = 5700 +- 150 K and log g = 4.5 +- 0.2) of intermediate age (tau = 2.3{sup +5.8}{sub -2.2} Gyr).

Lister, T. A. [Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA 93117 (United States); Anderson, D. R.; Smalley, B. S.; Wilson, D. M.; Bentley, S. J.; Hellier, C.; Maxted, P. F. L. [Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom); Gillon, M.; Triaud, A. H. M. J.; Mayor, M. [Observatoire de Geneve, Universite de Geneve, 51 Ch. des Maillettes, 1290 Sauverny (Switzerland); Hebb, L.; Collier Cameron, A.; Enoch, R.; Horne, K. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); West, R. G. [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Christian, D. J.; Joshi, Y. C. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, University Road, Belfast, BT7 1NN (United Kingdom); Haswell, C. A. [Department of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA (United Kingdom); Irwin, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kane, S. R., E-mail: tlister@lcogt.ne [NASA Exoplanet Science Institute, Caltech, MS 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States)

2009-09-20

80

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

81

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

E-print Network

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

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

2007-11-12

82

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

83

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

84

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

85

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

86

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

87

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

88

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

E-print Network

We report the discovery by the WASP transit survey of three new hot Jupiters, WASP-68 b, WASP-73 b and WASP-88 b. WASP-68 b has a mass of 0.95+-0.03 M_Jup, a radius of 1.24-0.06+0.10 R_Jup, and orbits a V=10.7 G0-type star (1.24+-0.03 M_sun, 1.69-0.06+0.11 R_sun, T_eff=5911+-60 K) with a period of 5.084298+-0.000015 days. Its size is typical of hot Jupiters with similar masses. WASP-73 b is significantly more massive (1.88-0.06+0.07 M_Jup) and slightly larger (1.16-0.08+0.12 R_Jup) than Jupiter. It orbits a V=10.5 F9-type star (1.34-0.04+0.05 M_sun, 2.07-0.08+0.19 R_sun, T_eff=6036+-120 K) every 4.08722+-0.00022 days. Despite its high irradiation (2.3 10^9 erg s^-1 cm^-2), WASP-73 b has a high mean density (1.20-0.30+0.26 \\rho_Jup) that suggests an enrichment of the planet in heavy elements. WASP-88 b is a 0.56+-0.08 M_Jup planet orbiting a V=11.4 F6-type star (1.45+-0.05 M_sun, 2.08-0.06+0.12 R_sun, T_eff=6431+-130 K) with a period of 4.954000+-0.000019 days. With a radius of 1.70-0.07+0.13 R_Jup, it joins t...

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

2013-01-01

89

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

90

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

91

A Spitzer Five-Band Analysis of the Jupiter-Sized Planet TrES-1  

E-print Network

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 {\\micron} (0.083 % {\\pm} 0.024 %, 1270 {\\pm} 110 K), 4.5 {\\micron} (0.094 % {\\pm} 0.024 %, 1126 {\\pm} 90 K), 5.8 {\\micron} (0.162 % {\\pm} 0.042 %, 1205 {\\pm} 130 K), 8.0 {\\micron} (0.0213 % {\\pm} 0.042 %, 1190 {\\pm} 130 K), and 16 {\\micron} (0.33 % {\\pm} 0.12 %, 1270 {\\pm} 310 K) bands. The eclipse depths can be explained, within 1$\\sigma$ 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 $e = 0.033^{+0.015}_{-0.031}$, consistent with a circular ...

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

2014-01-01

92

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

93

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

E-print Network

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

Seager, Sara

94

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

95

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

96

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.

2012-12-06

97

Jiggly Jupiter  

NSDL National Science Digital Library

In this activity, learners build edible models of Jupiter and Earth to compare their sizes and illustrate the planets' internal layers. Learners discuss how the Juno mission will infer details about Jupiter's interior by measuring its gravity field and magnetic field.

Institute, Lunar A.; Nasa

2011-01-01

98

Clouds in Low-mass, Low-density Planets  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

99

Transiting exoplanets from the CoRoT space mission. VII. The ``hot-Jupiter''-type planet CoRoT-5b  

NASA Astrophysics Data System (ADS)

Aims: The CoRoT space mission continues to photometrically monitor about 12 000 stars in its field-of-view for a series of target fields to search for transiting extrasolar planets ever since 2007. Deep transit signals can be detected quickly in the “alarm-mode” in parallel to the ongoing target field monitoring. CoRoT's first planets have been detected in this mode. Methods: The CoRoT raw lightcurves are filtered for orbital residuals, outliers, and low-frequency stellar signals. The phase folded lightcurve is used to fit the transit signal and derive the main planetary parameters. Radial velocity follow-up observations were initiated to secure the detection and to derive the planet mass. Results: We report the detection of CoRoT-5b, detected during observations of the LRa01 field, the first long-duration field in the galactic anti-center direction. CoRoT-5b is a “hot Jupiter-type” planet with a radius of 1.388+0.046-0.047 R_Jup, a mass of 0.467+0.047-0.024 M_Jup, and therefore, a mean density of 0.217+0.031-0.025 g cm-3. The planet orbits an F9V star of 14.0 mag in 4.0378962 ± 0.0000019 days at an orbital distance of 0.04947+0.00026-0.00029 AU. Observations made with SOPHIE spectrograph at the Observatoire de Haute Provence (07B.PNP.MOUT), France, and HARPS spectrograph at ESO La Silla Observatory (072.C-0488(E), 082.C-0312(A)), and partly based on observations made at the Anglo-Australian Telescope. The CoRoT space mission, launched on December 27, 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brasil, ESA, Germany, and Spain.

Rauer, H.; Queloz, D.; Csizmadia, Sz.; Deleuil, M.; Alonso, R.; Aigrain, S.; Almenara, J. M.; Auvergne, M.; Baglin, A.; Barge, P.; Bordé, P.; Bouchy, F.; Bruntt, H.; Cabrera, J.; Carone, L.; Carpano, S.; de La Reza, R.; Deeg, H. J.; Dvorak, R.; Erikson, A.; Fridlund, M.; Gandolfi, D.; Gillon, M.; Guillot, T.; Guenther, E.; Hatzes, A.; Hébrard, G.; Kabath, P.; Jorda, L.; Lammer, H.; Léger, A.; Llebaria, A.; Magain, P.; Mazeh, T.; Moutou, C.; Ollivier, M.; Pätzold, M.; Pont, F.; Rabus, M.; Renner, S.; Rouan, D.; Shporer, A.; Samuel, B.; Schneider, J.; Triaud, A. H. M. J.; Wuchterl, G.

2009-10-01

100

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

NASA Astrophysics Data System (ADS)

Context. In 1992 we began a precision radial velocity survey for planets around solar-like stars with the Coudé Echelle Spectrograph and the Long Camera (CES LC) at the 1.4 m telescope in La Silla (Chile) resulting in the discovery of the planet ? Hor b. We have continued the survey with the upgraded CES Very Long Camera (VLC) and the HARPS spectrographs, both at the 3.6 m telescope, until 2007. Aims: In this paper we present additional radial velocities for 31 stars of the original sample with higher precision. The observations cover a time span of up to 15 years and permit a search for Jupiter analogues. Methods: The survey was carried out with three different instruments/instrument configurations using the iodine absorption cell and the ThAr methods for wavelength calibration. We combine the data sets and perform a joint analysis for variability, trends, and periodicities. We compute Keplerian orbits for companions and detection limits in case of non-detections. Moreover, the HARPS radial velocities are analysed for correlations with activity indicators (CaII H&K and cross-correlation function shape). Results: We achieve a long-term RV precision of 15 m/s (CES+LC, 1992-1998), 9 m/s (CES+VLC, 1999-2006), and 2.8 m/s (HARPS, 2003-2009, including archive data), respectively. This enables us to confirm the known planetary signals in ? Hor and HR 506 as well as the three known planets around HR 3259. A steady RV trend for ? Ind A can be explained by a planetary companion and calls for direct imaging campaigns. On the other hand, we find previously reported trends to be smaller for ? Hyi and not present for ? Men. The candidate planet ? Eri b was not detected despite our better precision. Also the planet announced for HR 4523 cannot be confirmed. Long-term trends in several of our stars are compatible with known stellar companions. We provide a spectroscopic orbital solution for the binary HR 2400 and refined solutions for the planets around HR 506 and ? Hor. For some other stars the variations could be attributed to stellar activity, as e.g. the magnetic cycle in the case of HR 8323. Conclusions: The occurrence of two Jupiter-mass planets in our sample is in line with the estimate of 10% for the frequency of giant planets with periods smaller than 10 yr around solar-like stars. We have not detected a Jupiter analogue, while the detections limits for circular orbits indicate at 5 AU a sensitivity for minimum mass of at least 1MJup (2MJup) for 13% (61%) of the stars. Based on observations collected at the European Southern Observatory, La Silla Chile, ESO programmes 50.7-0095, 51.7-0054, 52.7-0002, 53.7-0064, 54.E-0424, 55.E-0361, 56.E-0490, 57.E-0142, 58.E-0134, 59.E-0597, 60.E-0386, 61.E-0589, 62.L-0490, 64.L-0568, 66.C-0482, 67.C-0296, 69.C-0723, 70.C-0047, 71.C-0599, 072.C-0513, 073.C-0784, 074.C-0012, 076.C-0878, 077.C-0530, 078.C-0833, 079.C-0681. Also based on data obtained from the ESO Science Archive Facility.Appendices are available in electronic form at http://www.aanda.orgTables of the radial velocities, bisector spans, and log R'_HK are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A78

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

2013-04-01

101

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

102

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

103

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

104

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

105

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

106

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

107

Exceptional Stars Origins, Companions, Masses and Planets  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

108

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

109

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

110

Hot Jupiters and Hot Spots: The Short- and Long-Term Chromospheric Activity on Stars with Giant Planets  

NASA Astrophysics Data System (ADS)

We monitored the chromospheric activity in the Ca II H and K lines of 13 solar-type stars (including the Sun): 8 of them over 3 years at the Canada-France-Hawaii Telescope (CFHT) and 5 in a single run at the Very Large Telescope (VLT). A total of 10 of the 13 targets have close planetary companions. All of the stars observed at the CFHT show long-term (months to years) changes in H and K intensity levels. Four stars display short-term (days) cyclical activity. For two, HD 73256 and ?1 Cet, the activity is likely associated with an active region rotating with the star; however, the flaring in excess of the rotational modulation may be associated with a hot Jupiter. A planetary companion remains a possibility for ?1 Cet. For the other two, HD 179949 and ? And, the cyclic variation is synchronized to the hot Jupiter's orbit. For both stars this synchronicity with the orbit is clearly seen in two out of three epochs. The effect is only marginal in the third epoch at which the seasonal level of chromospheric activity had changed for both stars. Short-term chromospheric activity appears weakly dependent on the mean K line reversal intensities for the sample of 13 stars. In addition, a suggestive correlation exists between this activity and the Mpsini of the star's hot Jupiter. Because of their small separation (<=0.1 AU), many of the hot Jupiters lie within the Alfvén radius of their host stars, which allows a direct magnetic interaction with the stellar surface. We discuss the conditions under which a planet's magnetic field might induce activity on the stellar surface and why no such effect was seen for the prime candidate, ? Boo. This work opens up the possibility of characterizing planet-star interactions, with implications for extrasolar planet magnetic fields and the energy contribution to stellar atmospheres. Based on observations collected at the Canada-France-Hawaii Telescope operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique of France, and the University of Hawaii, as well as data from the European Southern Observatory's Very Large Telescope, Chile (programme ESO 73.C-0694).

Shkolnik, E.; Walker, G. A. H.; Bohlender, D. A.; Gu, P.-G.; Kürster, M.

2005-04-01

111

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

112

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

E-print Network

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 Earth masses and that its orbital period is 1.93776 (+- 7x10^-5) days. Assuming coplanar orbits, an inclination of the GJ 876 planetary system to the plane of the sky of ~ 50 degrees gives the best fit. This inclination yields a mass for companion d of m = 7.53 +- 0.70 Earth masses, 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.

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

2005-10-18

113

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

114

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

115

A Dynamical Method for Measuring the Masses of Stars with Transiting Planets  

NASA Astrophysics Data System (ADS)

As a planet transits the face of a star, it accelerates along the line of sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent transverse deceleration breaks the time-reversal symmetry in the transit light curve of a spherical planet in a circular orbit around a perfectly symmetric star. For ``hot Jupiter'' systems, ingress advances at a higher rate than egress by a fraction of ~10-4-10-3. Forthcoming space telescopes such as Kepler or COROT will reach the sensitivity required to detect this asymmetry. The scaling of the fractional asymmetry with stellar mass M* and planetary orbital radius a, as M*/a2, is different from that of the orbital period, which scales as (M*/a3)-1/2. Therefore, this effect constitutes a new method for a purely dynamical determination of the mass of the star. Radial velocity data for the reflex motion of the star can then be used to determine the planet's mass. Although orbital eccentricity could introduce a larger asymmetry than the light-propagation delay, the eccentricity is expected to decay by tidal dissipation to negligible values for a close-in planet with no perturbing third body. Future detection of the eclipse of a planet's emission by its star could be used to measure the light-propagation delay across the orbital diameter, 46.7(a/7×1011 cm) s, and also determine the stellar mass from the orbital period.

Loeb, Abraham

2005-04-01

116

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

117

Extrasolar Planets and Prospects for Terrestrial Planets  

Microsoft Academic Search

Examination of ˜2000 sun--like stars has revealed 97 planets (as of 2002 Nov), all residing within our Milky Way Galaxy and within ˜200 light years of our Solar System. They have masses between 0.1 and 10 times that of Jupiter, and orbital sizes of 0.05--5 AU. Thus planets occupy the entire detectable domain of mass and orbits. News &summaries about

Geoffrey W. Marcy; R. Paul Butler; Steven S. Vogt; Debra A. Fischer

2004-01-01

118

A Stellar-mass-dependent Drop in Planet Occurrence Rates  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

119

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

120

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.

121

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

122

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

E-print Network

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

Viki Joergens; Ralph Neuhäuser

2003-06-23

123

A new Neptune-mass planet orbiting HD 219828  

Microsoft Academic Search

Two years ago a new benchmark for the planetary survey was set with the discoveries of three extrasolar planets with masses below 20 M_?. In particular, the serendipitous discovery of the 14 M_? 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

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

2007-01-01

124

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

125

Two Jovian-Mass Planets in Earthlike Orbits  

E-print Network

We report the discovery of two new planets: a 1.94 M_Jup planet in a 1.8-year orbit of HD 5319, and a 2.51 M_Jup planet in a 1.1-year orbit of HD 75898. The measured eccentricities are 0.12 for HD 5319 b and 0.10 for HD 75898 b, and Markov Chain Monte Carlo simulations based on derived orbital parameters indicate that the radial velocities of both stars are consistent with circular planet orbits. With low eccentricity and 1 < a < 2 AU, our new planets have orbits similar to terrestrial planets in the solar system. The radial velocity residuals of both stars have significant trends, likely arising from substellar or low-mass stellar companions.

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

2007-08-06

126

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

127

Types of Hot Jupiter Atmospheres  

NASA Astrophysics Data System (ADS)

Hot Jupiters, i.e. exoplanet gas giants, having masses comparable to the mass of Jupiter and semimajor axes shorter than 0.1 AU, are a unique class of objects. Since they are so close to the host stars, their atmospheres form and evolve under the action of very active gas dynamical processes caused by the gravitational field and irradiation of the host star. As a matter of fact, the atmospheres of several of these planets fill their Roche lobes , which results in a powerful outflow of material from the planet towards the host star. The energy budget of this process is so important that it almost solely governs the evolution of hot Jupiters gaseous envelopes. Based on the years of experience in the simulations of gas dynamics in mass-exchanging close binary stars, we have investigated specific features of hot Jupiters atmospheres. The analytical estimates and results of 3D numerical simulations, discussed in this Chapter, show that the gaseous envelopes around hot Jupiters may be significantly non-spherical and, at the same time, stationary and long-lived. These results are of fundamental importance for the interpretation of observational data.

Bisikalo, Dmitry V.; Kaygorodov, Pavel V.; Ionov, Dmitry E.; Shematovich, Valery I.

128

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

129

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

130

Transiting exoplanets from the CoRoT space mission. IX. CoRoT-6b: a transiting ``hot Jupiter'' planet in an 8.9d orbit around a low-metallicity star  

NASA Astrophysics Data System (ADS)

The CoRoT satellite exoplanetary team announces its sixth transiting planet in this paper. We describe and discuss the satellite observations as well as the complementary ground-based observations - photometric and spectroscopic - carried out to assess the planetary nature of the object and determine its specific physical parameters. The discovery reported here is a “hot Jupiterplanet in an 8.9d orbit, 18 stellar radii, or 0.08 AU, away from its primary star, which is a solar-type star (F9V) with an estimated age of 3.0 Gyr. The planet mass is close to 3 times that of Jupiter. The star has a metallicity of 0.2 dex lower than the Sun, and a relatively high 7Li abundance. While the light curve indicates a much higher level of activity than, e.g., the Sun, there is no sign of activity spectroscopically in e.g., the [Ca ii] H&K lines. The CoRoT space mission, launched on December 27, 2006, has been developed and is being operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA, The Research and Scientific Support Department of ESA, Germany and Spain.

Fridlund, M.; Hébrard, G.; Alonso, R.; Deleuil, M.; Gandolfi, D.; Gillon, M.; Bruntt, H.; Alapini, A.; Csizmadia, Sz.; Guillot, T.; Lammer, H.; Aigrain, S.; Almenara, J. M.; Auvergne, M.; Baglin, A.; Barge, P.; Bordé, P.; Bouchy, F.; Cabrera, J.; Carone, L.; Carpano, S.; Deeg, H. J.; de La Reza, R.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Guenther, E.; Gondoin, P.; den Hartog, R.; Hatzes, A.; Jorda, L.; Léger, A.; Llebaria, A.; Magain, P.; Mazeh, T.; Moutou, C.; Ollivier, M.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Samuel, B.; Schneider, J.; Shporer, A.; Stecklum, B.; Tingley, B.; Weingrill, J.; Wuchterl, G.

2010-03-01

131

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

132

Jupiter: Earth's Shield  

NSDL National Science Digital Library

Jupiter's immense gravity protects Earth from asteroids. In this video segment adapted from NOVA, scientists searching for signs of life in the universe identify solar systems with Jupiter-like planets that may be shielding smaller nearby Earth-like planets from comets and asteroids.

2005-12-17

133

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

134

A new Neptune-mass planet orbiting HD 219828  

E-print Network

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

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

2007-02-18

135

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

E-print Network

in star forming regions should have masses in the Jupiter­Saturn range and could be detectable in deep far in the do­ main of very wide field or all­sky imaging surveys, aiming at the detection of freely

Comerón, Fernando

136

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

137

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

SciTech Connect

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

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

2009-09-10

138

Dynamical corotation torques on low-mass planets  

NASA Astrophysics Data System (ADS)

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

Paardekooper, S.-J.

2014-11-01

139

Evolution of Giant Planets on Eccentric Orbits  

NASA Astrophysics Data System (ADS)

We have investigated the interaction of an eccentric orbit planet with a circumstellar disk by means of high-resolution hydrodynamical simulations. We have focused on the planet's mass range from one to a few Jupiter-masses. This study aims at characterizing the mass accretion and the orbital eccentricity evolution of giant planets. We find that the accretion rate depends on the orbital eccentricity of the protoplanet and that the accretion is pulsed on the orbital period, as found in simulations of binary star systems. Most of the mass is accreted while the protoplanet is around the apocenter position. A Jupiter-mass planet with orbital eccentricity e=0.3 accretes at a rate that is 33% higher than the accretion rate of a Jupiter-mass planet on a circular orbit. A 3 Jupiter-mass planet with e=0.1 is able to accrete, during one orbital period, 40% more mass than a similar size planet on a circular orbit. Simulations also indicate that a massive planet tend to sustain eccentricity growth in the disk, even with the planet revolving on a circular orbit, as already found for binary star systems. The interaction of the massive planet with the eccentric disk can then lead to the growth of the planet's orbital eccentricity. These results are consistent with observations of extrasolar planets. In fact, the most massive planets exhibit higher eccentricities than lower mass planets do. GD is supported by the UK Astrophysical Fluids Facility (UKAFF) through a UKAFF Fellowship. SL acknowledges support from NASA grant NNG04GG50G.

D'Angelo, G.; Lubow, S. H.; Bate, M. R.

2005-12-01

140

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

141

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

142

Methane planets and the mass-radius diagram  

NASA Astrophysics Data System (ADS)

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

Podolak, Morris; Helled, Ravit; Levi, Amit

2014-05-01

143

Search for earth mass planets and dark matter too  

SciTech Connect

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

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

1996-02-01

144

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

145

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

146

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

147

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

148

Formation of giant planets around stars with various masses  

E-print Network

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.

Kacper Kornet; Sebastian Wolf; Michal Rozyczka

2006-06-05

149

Pioneer 11's encounter with Jupiter and mission to Saturn  

NASA Technical Reports Server (NTRS)

Results of Pioneer 11's encounter with Jupiter are reviewed, and present plans for its approach to Saturn are discussed. The spacecraft is described together with its instrumentation, Jupiter-encounter operations, and scientific investigations. Scientific objectives at Saturn are outlined, including imaging of the planet, magnetospheric studies, measurements of Titan's mass and ephemeris, estimates of the mass of Saturn's rings, and penetration of the ring plane, particularly the D ring.

Dyer, J. W.

1975-01-01

150

Considerations on the Outward Migration of Jupiter and Saturn  

NASA Astrophysics Data System (ADS)

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

D'Angelo, G.; Marzari, F.

2011-12-01

151

Moons around Jupiter  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

152

Mars and Jupiter  

NSDL National Science Digital Library

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

Integrated Teaching and Learning Program,

153

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

154

Warm Jupiters as failed hot Jupiters  

NASA Astrophysics Data System (ADS)

The orbits of hot Jupiters often have surprisingly small semi-major axes, large eccentricities, or severe misalignments between their normals and their host stars' spin axes. In some formation scenarios invoking Kozai-Lidov oscillations, an external planetary companion drives a planet onto an orbit having these properties. The mutual inclinations for Kozai-Lidov oscillations can be large and have not been confirmed observationally. Here I present evidence for a population of eccentric warm Jupiters with eccentric giant companions with mutual inclinations just above 40 degrees. These planets may be undergoing a stalled version of tidal migration that produces warm Jupiters over hot Jupiters. I conclude by assessing the contribution of this mechanism to the overall population of short-period hot Jupiters, super-Earths, and mini-Neptunes.

Dawson, Rebekah Ilene; Chiang, Eugene

2015-01-01

155

An Overview of the Juno Mission to Jupiter  

NASA Technical Reports Server (NTRS)

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

Grammier, Richard S.

2006-01-01

156

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

157

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.

158

CLEA: The Revolution of the Moons of Jupiter  

NSDL National Science Digital Library

The purpose of this lab is to illustrate the measurement of the mass of a planet using Kepler's third law. The software provides a view of Jupiter at four magnifications, along with a highly accurate ephemeris program that draws the four Galilean satellites in their proper positions relative to the planet at any time. Students make observations of Jupiter and its satellites at regular intervals over a period of several weeks and, by graphing the separation of each moon from Jupiter versus time, they measure the period and radius of each satellite's orbit. This is sufficient information to derive the mass of Jupiter. Students use the mouse cursor to identify the moons and to measure distances. This is part of a larger collection of simulations, Project CLEA, hosted at Gettysburg College.

Marschall, Laurence; Snyder, Glenn; Cooper, P. R.; Hayden, Michael; Good, Rhonda

2009-05-20

159

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

160

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

161

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

162

A stellar-mass-dependent drop in planet occurrence rates  

E-print Network

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

Mulders, Gijs D; Apai, Daniel

2014-01-01

163

Abundances of Elements in Jupiter’s Atmosphere  

NASA Astrophysics Data System (ADS)

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

Desch, Steven; Monga, Nikhil

2014-11-01

164

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

165

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

166

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

167

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

168

The Pull of the Planets  

NSDL National Science Digital Library

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

2014-07-11

169

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

170

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

171

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

172

Constraining the Masses of the Kepler-11 Planets through Radial Velocity Measurements  

NASA Astrophysics Data System (ADS)

The six transiting planets of Kepler-11 have all been found to have ultra-low densities through N-body dynamical analysis of the transit timing variations (TTVs) of the six planets. Numerically reproducing TTVs has become a new method for solving the masses of planets, but this method is susceptible to certain dynamic degeneracies: the planet eccentricity is degenerate with the planet mass, and perturbations caused by non-transiting planets could be misattributed to the transiting planets. Furthermore, the masses of planets characterized by TTV analysis are systematically 2x lower than the masses (including non-detections) reported by radial velocity (RV) analysis for planets of the same radius. We address the discrepancy between the TTV- and RV-determined planet masses by measuring the RVs of Kepler-11 at opportunistic times, as determined by the ephemerides of the transiting planets. We place an upper limit on the masses of the Kepler-11 planets using RVs and preliminarily show that the RVs are consistent with the ultra-low mass scenario determined by the TTVs. The lack of disagreement between the TTVs and RVs in the Kepler-11 system bodes well for N-body simulations of TTVs for other Kepler systems that are too faint for RV follow-up.

Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard T.

2015-01-01

173

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

174

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.

175

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

176

Numerical theory of the motion of Jupiter's Galilean satellites  

NASA Astrophysics Data System (ADS)

A numerical theory of the motion of Jupiter’s Galilean satellites was constructed using 3767 absolute observations of the satellites. The theory was based on the numerical integration of the equations of motion of the satellites. The integration was carried out by Everhart’s method using the ERA software package developed at the Institute of Applied Astronomy (IAA). Perturbations due to the oblateness of the central planet, perturbations from Saturn and the Sun, and the mutual attraction of the satellites were taken into account in the integration. As a result, the coefficients of the Chebyshev series expansion for coordinates and velocities were found for the period from 1962 to 2010. The initial coordinates and velocities of the satellites, as well as their masses, the mass of Jupiter, and the harmonic coefficient J 2 of the potential of Jupiter, were adjusted. The resulting ephemerides were compared to those of Lieske and Lainey.

Kosmodamianskii, G. A.

2009-12-01

177

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

178

Jupiter and Saturn: Interior and Shape (Invited)  

NASA Astrophysics Data System (ADS)

Jupiter and Saturn are composed mostly of hydrogen and helium and a smaller fraction of heavy elements. The exact mass of those heavy elements and their distribution within the planets are not well constrained. In addition, due to the in-homogenous density distribution within the planetary interior and the rapid rotation, both Jupiter and Saturn have oblate shapes. The compositions and internal structures of Jupiter and Saturn are derived from structure (interior) models which use the measured physical properties of the planets such as mass, gravitational coefficients J2n, equatorial/mean radius, 1 bar temperature, rotation rate, and occasionally, the atmospheric He/H. Interior models, however, are typically static 1D models, and therefore do not account for the continuous planetary shape (i.e. radius as a function of latitude) and dynamical contributions (i.e. winds). First, I will discuss how the uncertainties in Saturn's internal rotation and shape affect its derived internal structure. It is found that for a rotation period of of 10h39mns Saturn's heavy element mass in the envelope is between 0 and 7 Earth masses, while the core mass ranges between 5 and 20 Earth masses. Interior models of Saturn with no ice/rock core are also possible. For a rotation period of 10h32mns the heavy element mass in the envelope is found to be lower than 4 Earth masses and the core mass is estimated to be 5-20 Earth masses. A derivation of Saturn's shape using the geodetic approach will also be presented. Next, I will show that the physical shape of a giant planet can be used to reveal information about its centrifugal potential, and therefore, its rotation. For Jupiter, it is found that both solid-body rotation (with System III rotation rate) and total differential rotation on cylinders up to a latitude between 20 and 30 degrees are consistent with its measured shape. Occultation measurements of the shapes of both Jupiter and Saturn can be used to constrain the depth of their zonal winds, although the case of Saturn is more complex due to the uncertainty in its rotation period, and therefore, wind velocities. Due to the importance of the planetary shape, it is suggested that it should be incorporated self-consistently in future structure models in order to make full use of Juno and Cassini data, and establish a better understanding of the planetary interior and dynamics. Finally, I will briefly discuss the water (O/H) abundance determination expected from Juno and how it can be used to reveal valuable information on Jupiter's internal structure and formation history.

Helled, R.

2013-12-01

179

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

SciTech Connect

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

Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Barnes, Stuart I.; Caldwell, Caroline [Department of Astronomy and McDonald Observatory, University of Texas at Austin, Austin, TX 78712 (United States); Wittenmyer, Robert A.; Horner, J. [Department of Astrophysics and Optics, School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Simon, Attila E., E-mail: paul@astro.as.utexas.edu [Konkoly Observatory of the Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary)

2012-04-10

180

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.

181

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

182

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

183

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

184

Trojans in Exosystems with Two Massive Planets  

NASA Astrophysics Data System (ADS)

We take as dynamical model for extrasolar planetary systems a central star like our Sun and two giant planets m 1 and m 2 like Jupiter and Saturn. We change the mass ratio ?=m 2/m 1 of the two large planets for a wide range of 1/16 < ? < 16. We also change the ratio between the initial semi-major axes (?=a 2/a 1) in the range of 1.2 < ? < 3 to model the different architecture of extrasolar planetary systems hosting two giant planets. The results for possible Trojans (Trojan planets) in the equilateral equilibrium points of the inner planet m 1 and the outer planet m 2 were derived with the aid of numerical integration. It turned out that in many configurations - depending on the mass ratios ? and the semi-major axes ratio ? - giant planets may host Trojans.

Dvorak, Rudolf; Zhou, Li-Yong; Baudisch, Helmut

2014-04-01

185

Mapping the stability field of Jupiter Trojans  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

186

Mapping the stability field of Jupiter Trojans  

NASA Astrophysics Data System (ADS)

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

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

1991-06-01

187

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

188

On the Tidal Origin of Hot Jupiter Stellar Obliquity Trends  

NASA Astrophysics Data System (ADS)

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

Dawson, Rebekah I.

2014-08-01

189

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

190

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

E-print Network

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

Joergens, Viki

191

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.

192

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

193

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

194

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

195

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.

196

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

197

Constraints on resonant-trapping for two planets embedded in a protoplanetary disc  

E-print Network

We investigate the evolution of two-planet systems embedded in a protoplanetary disc, which are composed of a Jupiter-mass planet plus another body located further out in the disc. We consider outermost planets with masses ranging from 10 earth masses to 1 M_J. We also examine the case of outermost bodies with masses resonance with the inner planet. If 30 resonance is established. If 80 resonance is favoured. Simulations of gas-accreting protoplanets of mass m_o > 20 M_E, trapped initially at the edge of the gap, or in the 2:1 resonance, also result in eventual capture in the 3:2 resonance as the planet mass grows to become close to the mass of Saturn. Our results suggest that there is a theoretical lower limit to the mass of an outer planet that can be captured into resonance with an inner Jovian planet, which is relevant to observations of extrasolar multiplanet systems. Furthermore, capture of a Saturn-like planet into the 3:2 resonance with a Jupiter-like planet is a very robust outcome of simulations. This result is relevant to recent scenarios of early Solar System evolution which require Saturn to have existed interior to the 2:1 resonance with Jupiter prior to the onset of the Late Heavy Bombardment.

Arnaud Pierens; Richard P. Nelson

2008-02-14

198

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

NASA Astrophysics Data System (ADS)

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

Hatzes, A. P.

2014-08-01

199

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

200

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

201

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

202

CONSEQUENCES OF THE EJECTION AND DISRUPTION OF GIANT PLANETS  

SciTech Connect

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

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

2011-05-10

203

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.

204

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

205

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

206

Extrapolating to "Hot Jupiters"  

E-print Network

Extrapolating to "Hot Jupiters" P. Zarka LESIA, Observatoire de Paris, Meudon Collaborators : R-15) HOM (L=7-11) Io-DAM (L=6) = 90° non-Io-DAM ? B [Zarka, 2000] · 5 radio planets · 6 LF (KOM, Lyman-) [Prangé et al., 1996] #12;[Zarka et al., 2001] Planetary Radio Emissions · nonthermal cyclotron

Demoulin, Pascal

207

Exploring the thermal emission of two new transiting planets from the WASP survey  

Microsoft Academic Search

We are shortly to announce the discovery of two transiting extra-solar planets from the Wide Angle Search for Planets (WASP) survey. One is expected to be the hottest of all hot Jupiters observable by Spitzer. The other may have suffered significant mass loss. Here we propose to use the unique capability of Spitzer to detect the thermal emission of both

Peter Wheatley; Suzanne Aigrain; Will Clarkson; Andrew Collier Cameron; Carole Haswell; Leslie Hebb; Guillaume Hebrard; Simon Hodgkin; Keith Horne; Stephen Kane; Andy Norton; Don Pollacco; Frederic Pont; Stephane Udry

2006-01-01

208

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

209

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

SciTech Connect

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

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

2010-06-01

210

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

SciTech Connect

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

Quarles, B.; Musielak, Z. E.; Cuntz, M., E-mail: billyq@uta.edu, E-mail: zmusielak@uta.edu, E-mail: cuntz@uta.edu [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

2012-05-01

211

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

212

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

213

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

214

Chemical Constraints on Hot Jupiter Migration  

NASA Astrophysics Data System (ADS)

The origin of close-in giant exoplanets 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 show that chemical abundances of exoplanetary atmospheres may be used to constrain their formation and/or migration mechanisms. We use spectroscopic observations, obtained using HST, Spitzer, and ground-based facilities, of several giant exoplanets to derive stringent constraints on their atmospheric C and O abundances. We then use the chemical abundances along with planet formation models to place the first rigorous constraints on the formation and migration pathways of the exoplanets in our sample. Our results suggest in particular that chemical depletions in hot Jupiter atmospheres have the potential to constrain their migration mechanisms which have thus far remained elusive based on dynamical measurements. 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. Our results open a new means for understanding the origins of exoplanets which have thus far been investigated based largely on dynamical properties of their orbits. We will discuss several open questions in this new frontier.

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

2015-01-01

215

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

216

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

217

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.

218

The role of migration and planet-planet scattering in shaping planetary systems  

NASA Astrophysics Data System (ADS)

Planets are thought to form from a circumstellar disk surrounding a star in its initial stages of evolution. The disk not only supplies the rough material for the accretion of solid bodies and their atmospheres but it also tidally interact with the growing planets moving them away from their initial location. Different types of planetary migration may explain the large number of 'hot Jupiters' observed among the known extrasolar planets. I will discuss how migration depends on the planet mass and how it may have also affected and shaped our solar system. Additional dynamical mechanisms are invoked to explain the large values of eccentricity and inclination observed in many extrasolar systems. Planet-planet scattering is possibly the most relevant causing both a significant inward migration of planets and exciting their eccentricity and inclination.

Marzari, F.

2014-04-01

219

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

220

Giant Planets  

E-print Network

We review the interior structure and evolution of Jupiter, Saturn, Uranus and Neptune, and giant exoplanets with particular emphasis on constraining their global composition. Compared to the first edition of this review, we provide a new discussion of the atmospheric compositions of the solar system giant planets, we discuss the discovery of oscillations of Jupiter and Saturn, the significant improvements in our understanding of the behavior of material at high pressures and the consequences for interior and evolution models. We place the giant planets in our Solar System in context with the trends seen for exoplanets.

Guillot, Tristan

2014-01-01

221

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

222

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

223

Full Jupiter Mosaic  

NASA Technical Reports Server (NTRS)

This image of Jupiter is produced from a 2x2 mosaic of photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI), and assembled by the LORRI team at the Johns Hopkins University Applied Physics Laboratory. The telescopic camera snapped the images during a 3-minute, 35-second span on February 10, when the spacecraft was 29 million kilometers (18 million miles) from Jupiter. At this distance, Jupiter's diameter was 1,015 LORRI pixels -- nearly filling the imager's entire (1,024-by-1,024 pixel) field of view. Features as small as 290 kilometers (180 miles) are visible.

Both the Great Red Spot and Little Red Spot are visible in the image, on the left and lower right, respectively. The apparent 'storm' on the planet's right limb is a section of the south tropical zone that has been detached from the region to its west (or left) by a 'disturbance' that scientists and amateur astronomers are watching closely.

At the time LORRI took these images, New Horizons was 820 million kilometers (510 million miles) from home -- nearly 51/2 times the distance between the Sun and Earth. This is the last full-disk image of Jupiter LORRI will produce, since Jupiter is appearing larger as New Horizons draws closer, and the imager will start to focus on specific areas of the planet for higher-resolution studies.

2007-01-01

224

A Planet at 5 AU Around 55 Cancri  

E-print Network

We report precise Doppler shift measurements of 55 Cancri (G8V) obtained from 1989 to 2002 at Lick Observatory. The velocities reveal evidence for an outer planetary companion to 55 Cancri orbiting at 5.5 AU. The velocities also confirm a second, inner planet at 0.11 AU. The outer planet is the first extrasolar planet found that orbits near or beyond the orbit of Jupiter. It was drawn from a sample of ~50 stars observed with sufficient duration and quality to detect a giant planet at 5 AU, implying that such planets are not rare. The properties of this jupiter analog may be compared directly to those of the Jovian planets in our Solar System. Its eccentricity is modest, e=0.16, compared with e=0.05 for both Jupiter and Saturn. Its mass is at least 4.0 jupiter masses (M sin i). The two planets do not perturb each other significantly. Moreover, a third planet of sub-Jupiter mass could easily survive in between these two known planets. Indeed a third periodicity remains in the velocity measurements with P = 44.3 d and a semi-amplitude of 13 m/s. This periodicity is caused either by a third planet at a=0.24 AU or by inhomogeneities on the stellar surface that rotates with period 42 d. The planet interpretation is more likely, as the stellar surface is quiet, exhibiting log(R'_{HK}) = -5.0 and brightness variations less than 1 millimag, and any hypothetical surface inhomogeneity would have to persist in longitude for 14 yr. Even with all three planets, an additional planet of terrestrial--mass could orbit stably at ~1 AU. The star 55 Cancri is apparently a normal, middle-aged main sequence star with a mass of 0.95 solar masses, rich in heavy elements ([Fe/H] = +0.27). This high metallicity raises the issue of the relationship between its age, rotation, and chromosphere.

Geoffrey W. Marcy; R. Paul Butler; Debra A. Fischer; Greg Laughlin; Steven S. Vogt; Gregory W. Henry; Dimitri Pourbaix

2002-07-14

225

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

226

Evolution of Giant Planets in Eccentric Disks  

NASA Astrophysics Data System (ADS)

We investigate the interaction between a giant planet and a viscous circumstellar disk by means of high-resolution, two-dimensional hydrodynamic simulations. We consider planetary masses that range from 1 to 3 Jupiter masses (MJ) and initial orbital eccentricities that range from 0 to 0.4. We find that a planet can cause eccentricity growth in a disk region adjacent to the planet's orbit, even if the planet's orbit is circular. Disk-planet interactions lead to growth in a planet's orbital eccentricity. The orbital eccentricities of a 2MJ and a 3MJ planet increase from 0 to 0.11 within about 3000 orbits. Over a similar time period, the orbital eccentricity of a 1MJ planet grows from 0 to 0.02. For a case of a 1MJ planet with an initial eccentricity of 0.01, the orbital eccentricity grows to 0.09 over 4000 orbits. Radial migration is directed inward but slows considerably as a planet's orbit becomes eccentric. If a planet's orbital eccentricity becomes sufficiently large, e>~0.2, migration can reverse and so be directed outward. The accretion rate toward a planet depends on both the disk and the planetary orbital eccentricity and is pulsed over the orbital period. Planetary mass growth rates increase with planetary orbital eccentricity. For e~0.2, the mass growth rate of a planet increases by ~30% above the value for e=0. For e>~0.1, most of the accretion within the planet's Roche lobe occurs when the planet is near the apocenter. Similar accretion modulation occurs for flow at the inner disk boundary, which represents accretion toward the star.

D'Angelo, Gennaro; Lubow, Stephen H.; Bate, Matthew R.

2006-12-01

227

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

228

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

229

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

230

PLANETARY RADII ACROSS FIVE ORDERS OF MAGNITUDE IN MASS AND STELLAR INSOLATION: APPLICATION TO TRANSITS  

E-print Network

; Beaulieuetal.2006).Comparative planetology, which once included only our solar system's planets and moons, now includes sub-Neptuneto super-Jupiter-mass plan- ets in other solar systems. Currently the most important for calculations of structure and con- traction of many planets) although one planet, HD 149026b, appears to be $2

Metchev, Stanimir

231

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.

232

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

233

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

234

Two New Candidate Planets in Eccentric Orbits  

Microsoft Academic Search

Doppler measurements of two G-type main-sequence stars, HD 210277 and HD 168443, reveal Keplerian variations that imply the presence of companions with masses (Msini) of 1.28 and 5.04 M_J (where M_J is the mass of Jupiter) and orbital periods of 437 and 58 days, respectively. The orbits have large eccentricities of e=0.45 and e=0.54, respectively. All nine known extrasolar planet

Geoffrey W. Marcy; R. Paul Butler; Steven S. Vogt; Debra Fischer; Michael C. Liu

1999-01-01

235

Formation and structure of the three Neptune-mass planets system around HD69830  

E-print Network

Since the discovery of the first giant planet outside the solar system in 1995 (Mayor & Queloz 1995), more than 180 extrasolar planets have been discovered. With improving detection capabilities, a new class of planets with masses 5-20 times larger than the Earth, at close distance from their parent star is rapidly emerging. Recently, the first system of three Neptune-mass planets has been discovered around the solar type star HD69830 (Lovis et al. 2006). Here, we present and discuss a possible formation scenario for this planetary system based on a consistent coupling between the extended core accretion model and evolutionary models (Alibert et al. 2005a, Baraffe et al. 2004,2006). We show that the innermost planet formed from an embryo having started inside the iceline is composed essentially of a rocky core surrounded by a tiny gaseous envelope. The two outermost planets started their formation beyond the iceline and, as a consequence, accrete a substantial amount of water ice during their formation. We calculate the present day thermodynamical conditions inside these two latter planets and show that they are made of a rocky core surrounded by a shell of fluid water and a gaseous envelope.

Yann Alibert; Isabelle Baraffe; Willy Benz; Gilles Chabrier; Christophe Mordasini; Christophe Lovis; Michel Mayor; Francesco Pepe; Francois Bouchy; Didier Queloz; Stephane Udry

2006-07-10

236

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

237

A NEW PLANET AROUND AN M DWARF: REVEALING A CORRELATION BETWEEN EXOPLANETS AND STELLAR MASS1  

Microsoft Academic Search

We report precise Doppler measurements of GJ 317 (M3.5 V) that reveal the presence of a planet with a minimum mass MP sin i ¼ 1:2 MJup in an eccentric, 692.9 day orbit. GJ 317 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.

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

238

A New Planet around an M Dwarf: Revealing a Correlation between Exoplanets and Stellar Mass  

Microsoft Academic Search

We report precise Doppler measurements of GJ 317 (M3.5 V) that reveal the presence of a planet with a minimum mass MPsini=1.2 MJup in an eccentric, 692.9 day orbit. GJ 317 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 a

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

2007-01-01

239

Influence of trans-neptunian objects on motion of major planets and limitation on the total TNO mass from planet and spacecraft ranging  

Microsoft Academic Search

Perturbations from asteroids and Trans-Neptunian Objects affect significantly on the orbits of planets and should be taken into account when high-accuracy planetary ephemerides are constructed. On the other hand, from an analysis of motion of the major planets by processing of precise measurements of spacecraft a limitation on the total TNO mass may be obtained. To estimate influence of TNO

E. V. Pitjeva

2010-01-01

240

Inertial mode oscillations of Jupiter  

NASA Technical Reports Server (NTRS)

The properties of the inertial modes of Jupiter are investigated using several different models for that planet. The inertial modes are rotationally induced oscillation modes for which the kinetic energy generally dominates the potential energy of oscillation. The frequency spectrum of the inertial modes mainly depends on the density stratification of Jupiter and sensitively reflects the existence or nonexistence of density discontinuities in the interior. A particularly interesting consequence of the calculations is that observations of the inertial oscillations of Jupiter may enable us to determine whether or not the dense hydrogen in the envelope of this planet undergoes the plasma phase transition (PPT). This may provide an astrophysical test of current theories of the thermodynamic properties of dense hydrogen. It is also found that the discontinuity modes associated with the PPT have observable amplitdues at the surface. These modes may provide an independent test of the interior structure of Jupiter.

Lee, Umin; Strohmayer, Tod E.; Van Horn, H. M.

1992-01-01

241

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

242

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.

Giesen, Juergen

243

The Terrestrial Planets Formation in the Solar-System Analogs  

Microsoft Academic Search

In this work, we numerically studied the terrestrial planets formation in the Solar-Systems Analogs using MERCURY (Chambers 1999). The Solar-System Analogs are herein defined as a solar-system like planetary system, where the system consists of two wide-separated Jupiter-like planets (e.g., 47 UMa, Ji et al. 2005) move about the central star on nearly circular orbits with low inclinations, then low-mass

Jianghui Ji; L. Liu; J. E. Chambers; R. P. Butler

2006-01-01

244

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

245

Measuring Masses and Densities of Small Planets found by NASA's Kepler Spacecraft with Radial Velocity Measurements from Keck/HIRES  

NASA Astrophysics Data System (ADS)

We use the Keck telescope and HIRES spectrometer to measure the masses of Kepler planet candidates. Analysis of 22 Kepler-identified planetary systems, holding 42 transiting planets (candidates) and 8 newly discovered non-transiting planets are presented herein. Combining the planet radius measurements from Kepler with mass measurements from Keck, we constrain the bulk density of short period planets that range in size from 1.0 to 3.0 Earth radii. Extensive ground based observations made by the Kepler Follow-up Program (KFOP) have provided extensive details about each KOI. Reconnaissance spectroscopy was used to refine the stellar and planet properties of each KOI at an early stage. SME spectral analysis and asteroseismology, when available, are used to obtain the final stellar properties. Adaptive Optics and speckle imaging constrain the presence of background eclipsing binaries that could masquerade as transiting planets. By combining ground based follow-up observations with Kepler photometry, a false positive probability is calculated for each KOI. An MCMC analysis that combines both Kepler photometry and Keck radial velocity measurements determines the final orbital parameters and planet properties for each system. The resulting mass vs. radius diagram for the planets reveals that radii increase with mass monotonically, well represented by a power law for the smallest planets. This M-R relationship offers key insights about the internal composition of the planets and the division between rocky and gaseous planets.

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

2013-06-01

246

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

247

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

248

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

249

Detection of a Neptune-Mass Planet in the rho1 Cancri System Using the Hobby-Eberly Telescope  

Microsoft Academic Search

We report the detection of the lowest mass extrasolar planet yet found around a Sun-like star-a planet with an Msini of only 14.21+\\/-2.91 M? in an extremely short period orbit (P=2.808 days) around rho1 Cancri, a planetary system that already has three known planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner planet

Barbara E. McArthur; Michael Endl; William D. Cochran; G. Fritz Benedict; Debra A. Fischer; Geoffrey W. Marcy; R. Paul Butler; Dominique Naef; Michel Mayor; Diedre Queloz; Stephane Udry; Thomas E. Harrison

2004-01-01

250

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

251

The Fate of Scattered Planets  

NASA Astrophysics Data System (ADS)

As gas giant planets evolve, they may scatter other planets far from their original orbits to produce hot Jupiters or rogue planets that are not gravitationally bound to any star. Here, we consider planets cast out to large orbital distances on eccentric, bound orbits through a gaseous disk. With simple numerical models, we show that super-Earths can interact with the gas through dynamical friction to settle in the remote outer regions of a planetary system. Outcomes depend on planet mass, the initial scattered orbit, and the evolution of the time-dependent disk. Efficient orbital damping by dynamical friction requires planets at least as massive as the Earth. More massive, longer-lived disks damp eccentricities more efficiently than less massive, short-lived ones. Transition disks with an expanding inner cavity can circularize orbits at larger distances than disks that experience a global (homologous) decay in surface density. Thus, orbits of remote planets may reveal the evolutionary history of their primordial gas disks. A remote planet with an orbital distance ~100 AU from the Sun is plausible and might explain correlations in the orbital parameters of several distant trans-Neptunian objects.

Bromley, Benjamin C.; Kenyon, Scott J.

2014-12-01

252

Measurement of planet masses with transit timing variations due to synodic "chopping" effects  

E-print Network

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 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 analyzed with full dynamical analyses. We show that when chopping is measured, the ma...

Deck, Katherine M

2014-01-01

253

Discovery of WASP-65b and WASP-75b: Two Hot Jupiters Without Highly Inflated Radii  

E-print Network

We report the discovery of two transiting hot Jupiters, WASP-65b (M_pl = 1.55 +/- 0.16 M_J; R_pl = 1.11 +/- 0.06 R_J), and WASP-75b (M_pl = 1.07 +/- 0.05 M_J; R_pl = 1.27 +/- 0.05 R_J). They orbit their host star every 2.311, and 2.484 days, respectively. The planet host WASP-65 is a G6 star (T_eff = 5600 K, [Fe/H] = -0.07 +/- 0.07, age > 8 Gyr); WASP-75 is an F9 star (T_eff = 6100 K, [Fe/H] = 0.07 +/- 0.09, age of 3 Gyr). The mean density of WASP-65b is similar to that of Jupiter (rho_pl = 1.13 +/- 0.08 rho_J), and in fact, WASP-65b is one of the densest planets with a mass between 0.1 and 2.0 M_J, a mass range in which a large fraction of the known planets have been found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of around 1.5 M_J, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of Jupiter-mass WASP-75b is slightly inflated (< 10%) as compared to theoretical planet models with no core, ...

Chew, Y Gómez Maqueo; Pollacco, D; Brown, D J A; Doyle, A P; Cameron, A Collier; Gillon, M; Lendl, M; Smalley, B; Triaud, A H M J; West, R G; Wheatley, P J; Busuttil, R; Liebig, C; Anderson, D R; Armstrong, D J; Barros, S C C; Bento, J; Bochinski, J; Burwitz, V; Delrez, L; Enoch, B; Fumel, A; Haswell, C A; Hébrard, G; Hellier, C; Holmes, S; Jehin, E; Kolb, U; McCormac, J; Miller, G R M; Norton, A J; Pepe, F; Queloz, D; Rodríguez, J; Ségransan, D; Skillen, I; Stassun, K G; Udry, S; Watson, C A

2013-01-01

254

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

255

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

256

Convection and Mixing in Giant Planet Evolution  

E-print Network

The primordial internal structures of gas giant planets are unknown. Often giant planets are modeled under the assumption that they are adiabatic, convective, and homogeneously mixed, but this is not necessarily correct. In this work, we present the first self-consistent calculation of convective transport of both heat and material as the planets evolve. We examine how planetary evolution depends on the initial composition and its distribution, whether the internal structure changes with time, and if so, how it affects the evolution. We consider various primordial distributions, different compositions, and different mixing efficiencies and follow the distribution of heavy elements in a Jupiter-mass planet as it evolves. We show that a heavy-element core cannot be eroded by convection if there is a sharp compositional change at the core-envelope boundary. If the heavy elements are initially distributed within the planet according to some compositional gradient, mixing occurs in the outer regions resulting in a...

Vazan, Allona; Kovetz, Attay; Podolak, Morris

2015-01-01

257

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

258

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

259

Orbits and Interiors of Planets  

NASA Astrophysics Data System (ADS)

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

Batygin, Konstantin

2012-05-01

260

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

261

On the migration-induced resonances in a system of two planets with masses in the Earth mass range  

E-print Network

We investigate orbital resonances expected to arise when a system of two planets, with masses in the range 1-4 Earth masses, undergoes convergent migration while embedded in a section of gaseous disc where the flow is laminar. We consider surface densities corresponding to 0.5-4 times that expected for a minimum mass solar nebula at 5.2 AU. Using hydrodynamic simulations we find that when the configuration is such that convergent migration occurs the planets can become locked in a first order commensurability for which the period ratio is (p+1)/p with p being an integer and migrate together maintaining it for many orbits. Relatively rapid convergent migration as tends to occur for disparate masses, results in commensurabilities with p larger than 2. However, in these cases the dynamics is found to have a stochastic character. When the convergent migration is slower, such as occurs in the equal mass case, lower p commensurabilities such as 3:2 are attained which show much greater stability. In one already known example of a system with nearly equal masses in the several Earth mass range (planets around pulsar PSR B1257+12) the two largest planets are intriguingly close to a 3:2 commensurability. A very similar behaviour is obtained when the systems are modeled using an N body code with simple prescriptions for the disc planet interaction. Using that, we found that an 8:7 resonance established in a hydrodynamic simulation run for 10-100 thousand orbits could be maintained for more than million orbits. Resonant capture leads to a rise in eccentricities that can be predicted using a simple analytic model constructed in this paper. We find that the system with the 8:7 commensurability is fully consistent with this prediction.

J. C. B. Papaloizou; E. Szuszkiewicz

2005-07-26

262

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

263

History of the mass of Mercury  

NASA Technical Reports Server (NTRS)

This paper discusses the calculation of the masses of planets, as a means to construct reliable tables for their positions. Emphasis is placed on the four inner planets and the moon, with additional consideration given to the history of the masses of Jupiter and Saturn. A smooth curve can be drawn with the logarithm of the masses of the earth, Venus, Mars, and the moon, but the point for Mercury lies substantially off the curve. An investigation of the material content, surface examination, and planet radius for the planets leads to a reexamination of the history of the value for the mass of Mercury.

Lyttleton, R. A.

1980-01-01

264

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

265

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

266

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

267

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

268

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

NASA Astrophysics Data System (ADS)

Planets such as 55 Cancri e orbiting stars with a high carbon-to-oxygen ratio may consist primarily of silicon and carbon, with successive layers of carbon, silicon carbide, and iron. The behavior of silicon-carbon materials at the extreme pressures prevalent in planetary interiors, however, has not yet been sufficiently understood. In this work, we use simulations based on density functional theory to determine high-pressure phase transitions in the silicon-carbon system, including the prediction of new stable compounds with Si2C and SiC2 stoichiometry at high pressures. We compute equations of state for these silicon-carbon compounds as a function of pressure, and hence derive interior structural models and mass-radius relationships for planets composed of silicon and carbon. Notably, we predict a substantially smaller radius for SiC planets than in previous models, and find that mass radius relationships for SiC planets are indistinguishable from those of silicate planets. We also compute a new equation of state for iron. We rederive interior models for 55 Cancri e and are able to place more stringent restrictions on its composition.

Wilson, Hugh F.; Militzer, Burkhard

2014-09-01

269

Detection of a NEPTUNE-mass planet in the $?^{1}$ Cancri system using the Hobby-Eberly Telescope  

E-print Network

We report the detection of the lowest mass extra-solar planet yet found around a Sun-like star - a planet with an \\msini of only 14.21 $\\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\\rho^{1}$ Cancri, a planetary system which already has three known planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner planet at 0.04 AU. We estimate an inclination of the outer planet $\\rho^{1}$ Cancri d, based upon {\\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner planet of only 17.7 $\\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.

Barbara E. McArthur; Michael Endl; William D. Cochran; G. Fritz Benedict; Debra A. Fischer; Geoffrey W. Marcy; R. Paul Butler; Dominique Naef; Michel Mayor; Diedre Queloz; Stephane Udry; Thomas E. Harrison

2004-08-31

270

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

271

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

272

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

273

Planet Hunters VII. Discovery of a New Low-Mass, Low-Density Planet (PH3 c) Orbiting Kepler-289 with Mass Measurements of Two Additional Planets (PH3 b and d)  

E-print Network

We report the discovery of one newly confirmed planet ($P=66.06$ days, $R_{\\rm{P}}=2.68\\pm0.17R_\\oplus$) and mass determinations of two previously validated Kepler planets, Kepler-289 b ($P=34.55$ days, $R_{\\rm{P}}=2.15\\pm0.10R_\\oplus$) and Kepler-289-c ($P=125.85$ days, $R_{\\rm{P}}=11.59\\pm0.10R_\\oplus$), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a $1:2:4$ Laplace resonance. The outer planet has very deep ($\\sim1.3%$), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young ($\\sim1$ Gyr as determined by isochrones and gyrochronology), Sun-like star with $M_*=1.08\\pm0.02M_\\odot$, $R_*=1.00\\pm0.02R_\\odot$, and $T_{\\rm{eff}}=5990\\pm38$ K. The middle planet's large TTV amplitude ($\\sim5$ hours) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allo...

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

2014-01-01

274

Rapid heating of the atmosphere of an extrasolar planet.  

PubMed

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

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

2009-01-29

275

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

276

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

277

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

278

KEPLER PLANETS: A TALE OF EVAPORATION  

SciTech Connect

Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ?0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R{sub ?}. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ?0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M{sub ?} and the majority of them should have core masses of a few Earth masses.

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

2013-10-01

279

Voyager to Jupiter and Saturn  

NASA Technical Reports Server (NTRS)

The NASA Voyager mission to explore planets of the outer solar system is summarized. The mission schedule and profiles for encounters with Jupiter and Saturn, and possibly with Uranus and Pluto are included along with a description of the spacecraft and its trajectories. Scientific investigations to be made and the instruments carried are also discussed.

1977-01-01

280

Chaotic capture of Jupiter's Trojan asteroids in the early SolarSystem  

Microsoft Academic Search

Jupiter's Trojans are asteroids that follow essentially the same orbit as Jupiter, but lead or trail the planet by an angular distance of ~60 degrees (co-orbital motion). They are hypothesized to be planetesimals that formed near Jupiter and were captured onto their current orbits while Jupiter was growing, possibly with the help of gas drag and\\/or collisions. This idea, however,

A. Morbidelli; H. F. Levison; K. Tsiganis; R. Gomes

2005-01-01

281

PLANETS AROUND THE K-GIANTS BD+20 274 AND HD 219415  

SciTech Connect

We present the discovery of planet-mass companions to two giant stars by the ongoing Penn State-Torun Planet Search conducted with the 9.2 m Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274, has a 4.2 M{sub J} minimum mass planet orbiting the star at a 578 day period and a more distant, likely stellar-mass companion. The best currently available model of the planet orbiting the K0-giant HD 219415 points to a {approx}> Jupiter-mass companion in a 5.7 year, eccentric orbit around the star, making it the longest period planet yet detected by our survey. This planet has an amplitude of {approx}18 m s{sup -1}, comparable to the median radial velocity 'jitter', typical of giant stars.

Gettel, S.; Wolszczan, A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Niedzielski, A.; Nowak, G.; Adamow, M.; Zielinski, P.; Maciejewski, G., E-mail: sgettel@astro.psu.edu, E-mail: alex@astro.psu.edu, E-mail: Andrzej.Niedzielski@astri.uni.torun.pl [Torun Center for Astronomy, Nicolaus Copernicus University, ul. Gagarina 11, 87-100 Torun (Poland)

2012-09-01

282

Jupiter Eruptions  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

This visible-light image is from NASA's Hubble Space Telescope taken on May 11, 2007. It shows the turbulent pattern generated by the two plumes on the upper left part of Jupiter.

Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vi gorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

2008-01-01

283

New Constraints on the Composition of Jupiter from Galileo Measurements and Interior Models  

E-print Network

Using the helium abundance measured by Galileo in the atmosphere of Jupiter and interior models reproducing the observed external gravitational field, we derive new constraints on the composition and structure of the planet. We conclude that, except for helium which must be more abundant in the metallic interior than in the molecular envelope, Jupiter could be homogeneous (no core) or could have a central dense core up to 12 Earth masses. The mass fraction of heavy elements is less than 7.5 times the solar value in the metallic envelope and between 1 and 7.2 times solar in the molecular envelope. The total amount of elements other than hydrogen and helium in the planet is between 11 and 45 Earth masses.

Tristan Guillot; Daniel Gautier; William B. Hubbard

1997-07-17

284

The interior of Jupiter Tristan Guillot  

E-print Network

3 The interior of Jupiter Tristan Guillot Observatoire de la C^ote d'Azur, CNRS UMR 6529 David J of Arizona Didier Saumon Los Alamos National Laboratory 3.1 INTRODUCTION Jupiter, owing to its large mass and rapid formation, played a crucial role in shaping the solar system as we know it today. Jupiter mostly

Guillot, Tristan

285

Accretion of Jupiter's Atmosphere from a  

E-print Network

Accretion of Jupiter's Atmosphere from a Supernova-Contaminated Molecular Cloud Henry Throop 2010, #1409 #12;Jupiter's Atmosphere · Mass Spectrometer aboard Galileo Probe · Measured atomic and molecular species to ~20 bars · Found Jupiter atmosphere to be 2-6x higher in metals vs. Sun · C, S,Ar, Kr

Throop, Henry

286

Journey to a Star Rich with Planets  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for movie of Journey to a Star Rich with Planets

This artist's animation takes us on a journey to 55 Cancri, a star with a family of five known planets - the most planets discovered so far around a star besides our own.

The animation begins on Earth, with a view of the night sky and 55 Cancri (flashing dot), located 41 light-years away in the constellation Cancer. It then zooms through our solar system, passing our asteroids and planets, until finally arriving at the outskirts of 55 Cancri.

The first planet to appear is the farthest out from the star -- a giant planet, probably made of gas, with a mass four times that of Jupiter. This planet orbits its star every 14 years, similar to Jupiter's 11.9-year orbit.

As the movie continues, the three inner planets are shown, the closest of which is about 10 to 13 times the mass of Earth with an orbital period of less than three days.

Zooming out, the animation highlights the newest member of the 55 Cancri family - a massive planet, likely made of gas, water and rock, about 45 times the mass of Earth and orbiting the star every 260 days. This planet is the fourth out from the star, and lies in the system's habitable zone (green). A habitable zone is the place around a star where liquid water would persist. Though the newest planet probably has a thick gaseous envelope, astronomers speculate that it could have one or more moons. In our own solar system, moons are common, so it seems likely that they also orbit planets in other solar systems. If such moons do exist, and if they are as large as Mars or Earth, astronomers speculate that they would retain atmospheres and surface liquid water that might make interesting environments for the development of life.

The animation ends with a comparison between 55 Cancri and our solar system.

The colors of the illustrated planets were chosen to resemble those of our own solar system. Astronomers do not know what the planets look like.

2007-01-01

287

PLANET HUNTERS: A TRANSITING CIRCUMBINARY PLANET IN A QUADRUPLE STAR SYSTEM  

SciTech Connect

We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every {approx}137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625. The 6.18 {+-} 0.17 R{sub Circled-Plus} planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 {+-} 0.044 R{sub Sun }, 1.528 {+-} 0.087 M{sub Sun }) and M dwarf (0.378 {+-} 0.023 R{sub Sun }, 0.408 {+-} 0.024 M{sub Sun }). For the planet, we find an upper mass limit of 169 M{sub Circled-Plus} (0.531 Jupiter masses) at the 99.7% confidence level. With a radius and mass less than that of Jupiter, PH1b is well within the planetary regime. Outside the planet's orbit, at {approx}1000 AU, a previously unknown visual binary has been identified that is likely bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

Schwamb, Megan E.; Schawinski, Kevin [Yale Center for Astronomy and Astrophysics, Yale University, P. O. Box 208121, New Haven, CT 06520 (United States); Orosz, Jerome A.; Welsh, William F., E-mail: megan.schwamb@yale.edu [Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1221 (United States); and others

2013-05-10

288

Planets in Transit V Passages of Discovery  

NASA Astrophysics Data System (ADS)

Eclipses of the Sun have long influenced culture, history, and science. The analogous but much more subtle phenomena of a transit of the Sun by Mercury was first predicted by Johannes Kepler. Soon, predictions of transits of Venus inspired bold expeditions to better understand the scale of our solar system. These passages of discovery sometimes succeeded scientifically but always captured the public imagination and played an unexpected role in history. The possibility of detecting planets outside the solar system by the transit method was first outlined by Otto Struve in 1952. Early inquiries usually assumed that extrasolar planetary systems would have a distribution of planetary radii and orbital sizes like the solar system. The detection of transits from the ground in such systems would be daunting. The recent, unexpected discovery of a class of extrasolar planets (by the radial velocity technique) with orbital periods less than a week and masses near to the planet Jupiter has resulted in a resurgence of interest in the transit method. These so called "hot Jupiters", can produce transits that are likely enough, frequent enough, the transit method. These so called "hot Jupiters", can produce transits that are likely enough, frequent enough, and deep enough that ground-based transit searches can be successful. In November 1999, a planet orbiting the star HD 209458 was found to transit, and many measurements of the transit have since been made that challenge formation and evolution theories. Numerous ground based searches for transits are now underway. Several planned high precision space-based missions designed to detect transits of earth-sized planets, also have the potential to detect transits of hundreds of "hot Jupiters". These efforts and the upcoming transit of the Sun by Venus on June 8, 2004 present an opportunity for transits to once again capture the public imagination and perhaps play a role in history.

Castellano, T. P.

2003-05-01

289

Micro-arcsecond light bending by Jupiter  

E-print Network

The detectors designed for Gaia, the next ESA space astrometry mission to be launched in 2011, will allow to observe repeatedly stars very close to Jupiter's limb. This will open a unique opportunity to test General Relativity by performing many Eddington-like experiments through the comparison between the pattern of a starfield observed with or without Jupiter. We have derived the main formulas relevant for the monopole and quadrupole light deflection by an oblate planet and developed a simulator to investigate the processing of the Gaia astrometric observation in the vicinity of the planet. The results show that such an experiment carried out with the Gaia data will provide a new fully independent determination of the PPN parameter gamma by means of differential astrometric measurements and, more importantly, for the first time will evidence the bending effect due to the quadrupole moment with a 3-sigma confidence level. Given the accuracy of the experiment for the monopole deflection, this will permit to test alternative modelling of the light bending by moving masses.

MT Crosta; F Mignard

2005-12-14

290

Planets around Low-mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems  

NASA Astrophysics Data System (ADS)

We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (gsim1 M Jup) around 122 newly identified nearby (lsim40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M ?) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M Jup at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M Jup; L0+2-1; 120 ± 20 AU), GJ 3629 B (64+30-23 M Jup; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M Jup; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M Jup; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M Jup planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M Jup range like those orbiting HR 8799 and ? Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M Jup) companions to single M dwarfs between 10-100 AU is 2.8+2.4-1.5%. Altogether we find that giant planets, especially massive ones, are rare in the outskirts of M dwarf planetary systems. Although the first directly imaged planets were found around massive stars, there is currently no statistical evidence for a trend of giant planet frequency with stellar host mass at large separations as predicted by the disk instability model of giant planet formation. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. This work was also based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Tamura, Motohide

2015-01-01

291

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

E-print Network

This paper presents multi-band photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of 5 new ground-based transit light curves obtained in May 2007. Together with one already published light curve we have at hand a total of 6 light curves, spanning 29 days. The analysis of the data yields an orbital period P = 2.64386+-0.00003 days, mid-transit time T_c [HJD] =2454235.8355+-0.0001, planet mass M_p = 23.1+-0.9 M_{\\earth} = 0.073+-0.003 M_{Jup}, planet radius R_p = 4.2+-0.2 R_{\\earth} = 0.37+-0.01 R_{Jup} and stellar radius R_s = 0.45+-0.02 R_{\\sun}. Our typical precision for the mid transit timing for each transit is about 30 seconds. We searched the data for a possible signature of a second planet in the system through transit timing variations (TTV) and variation of the impact parameter. The analysis could not rule out a small, of the order of a minute, TTV and a long-term modulation of the impact parameter, of the order of +0.2 year^{-1}.

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

2008-05-26

292

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

SciTech Connect

We perform modeling investigations to aid in understanding the atmospheres and composition of small planets of ?2-4 Earth radii, which are now known to be common in our Galaxy. GJ 1214b is a well-studied example whose atmospheric transmission spectrum has been observed by many investigators. Here we take a step back from GJ 1214b to investigate the role that planetary mass, composition, and temperature play in impacting the transmission spectra of these low-mass low-density (LMLD) planets. Under the assumption that these planets accrete modest hydrogen-dominated atmospheres and planetesimals, we use population synthesis models to show that predicted metal enrichments of the H/He envelope are high, with metal mass fraction Z{sub env} values commonly 0.6-0.9, or ?100-400+ times solar. The high mean molecular weight of such atmospheres (? ? 5-12) would naturally help to flatten the transmission spectrum of most LMLD planets. The high metal abundance would also provide significant condensible material for cloud formation. It is known that the H/He abundance in Uranus and Neptune decreases with depth, and we show that atmospheric evaporation of LMLD planets could expose atmospheric layers with gradually higher Z{sub env}. However, values of Z{sub env} close to solar composition can also arise, so diversity should be expected. Photochemically produced hazes, potentially due to methane photolysis, are another possibility for obscuring transmission spectra. Such hazes may not form above T{sub eq} of ?800-1100 K, which is testable if such warm, otherwise low mean molecular weight atmospheres are stable against atmospheric evaporation. We find that available transmission data are consistent with relatively high mean molecular weight atmospheres for GJ 1214b and 'warm Neptune' GJ 436b. We examine future prospects for characterizing GJ 1214b with Hubble and the James Webb Space Telescope.

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

2013-09-20

293

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

SciTech Connect

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

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

2009-09-10

294

Making other Earths: Dynamical Simulations of Terrestrial Planet Formation and Water Delivery  

E-print Network

We present results from 42 simulations of late stage planetary accretion, focusing on the delivery of volatiles (primarily water) to the terrestrial planets. Our simulations include both planetary "embryos" (defined as Moon to Mars sized protoplanets) and planetesimals, assuming that the embryos formed via oligarchic growth. We investigate volatile delivery as a function of Jupiter's mass, position and eccentricity, the position of the snow line, and the density (in solids) of the solar nebula. In all simulations, we form 1-4 terrestrial planets inside 2 AU, which vary in mass and volatile content. In 42 simulations we have formed 43 planets between 0.8 and 1.5 AU, including 11 "habitable" planets between 0.9 and 1.1 AU. These planets range from dry worlds to "water worlds" with 100+ oceans of water (1 ocean = 1.5x10^24 g), and vary in mass between 0.23 and 3.85 Earth masses. There is a good deal of stochastic noise in these simulations, but the most important parameter is the planetesimal mass we choose, which reflects the surface density in solids past the snow line. A high density in this region results in the formation of a smaller number of terrestrial planets with larger masses and higher water content, as compared with planets which form in systems with lower densities. We find that an eccentric Jupiter produces drier terrestrial planets with higher eccentricities than a circular one. In cases with Jupiter at 7 AU, we form what we call "super embryos," 1-2 Earth mass protoplanets which can serve as the accretion seeds for 2+ Earth mass planets with large water contents.

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

2003-08-09

295

The M Dwarf GJ 436 and its Neptune-Mass Planet  

E-print Network

We determine stellar parameters for the M dwarf GJ 436 that hosts a Neptune-mass planet. We employ primarily spectral modeling at low and high resolution, examining the agreement between model and observed optical spectra of five comparison stars of type, M0-M3. Modeling high resolution optical spectra suffers from uncertainties in TiO transitions, affecting the predicted strengths of both atomic and molecular lines in M dwarfs. The determination of Teff, gravity, and metallicity from optical spectra remains at ~10%. As molecules provide opacity both in lines and as an effective continuum, determing molecular transition parameters remains a challenge facing models such as the PHOENIX series, best verified with high resolution and spectrophotometric spectra. Our analysis of GJ 436 yields an effective temperature of Teff = 3350 +/- 300 K and a mass of 0.44 Msun. New Doppler measurements for GJ 436 with a precision of 3 m/s taken during 6 years improve the Keplerian model of the planet, giving a minimum mass, M sin i = 0.0713 Mjup = 22.6 Mearth, period, P = 2.6439 d, and e = 0.16 +/- 0.02. The noncircular orbit contrasts with the tidally circularized orbits of all close-in exoplanets, implying either ongoing pumping of eccentricity by a more distant companion, or a higher Q value for this low-mass planet. The velocities indeed reveal a long term trend, indicating a possible distant companion.

H. L. Maness; G. W. Marcy; E. B. Ford; P. H. Hauschildt; A. T. Shreve; G. B. Basri; R. P. Butler; S. S. Vogt

2006-08-11

296

The Voyager flights to Jupiter and Saturn  

NASA Technical Reports Server (NTRS)

The results of the mini-Grand Tour to Jupiter and Saturn by the Voyager 1 and 2 spacecraft are highlighted. Features of the spacecraft are depicted including the 11 instruments designed to probe the planets and their magnetic environments, the rings of Saturn, the fleets of satellites escorting the planets, and the interplanetary medium. Major scientific discoveries relating to these phenomena are summarized.

1982-01-01

297

Hot Jupiters from Coplanar High-eccentricity Migration  

NASA Astrophysics Data System (ADS)

The question of what mechanism is responsible for delivering giant planets into short-periods orbits (<10 days), the so-called hot Jupiters (HJs), is one of the fundamental unresolved questions in planet formation. In this talk, I propose that most HJs are formed through the secular interaction of two planets in eccentric and nearly coplanar orbits and tidal dissipation due to the host star, mechanism which I term coplanar high-eccentricity migration (CHEM). I will show that the HJs formed by CHEM can well-reproduce the observed period distribution, as well as explain why most HJs have low stellar obliquities. I further provide with testable predictions regarding the properties (e.g., masses and orbital periods) of the outer perturber and formation timescales in HJ systems.

Petrovich, Cristobal

2014-11-01

298

Outer Planet Icy Satellites  

NASA Technical Reports Server (NTRS)

An outer planet icy satellite is any one of the celestial bodies in orbit around Jupiter, Saturn, Uranus, Neptune, or Pluto. They range from large, planet-like geologically active worlds with significant atmospheres to tiny irregular objects tens of kilometers in diameter. These bodies are all believed to have some type of frozen volatile, existing alone or in combination with other volatiles.

Buratti, B.

1994-01-01

299

Extrasolar Planet Transit Light Curves and a Method to Select the Best Planet Candidates for Mass Follow-up  

E-print Network

A unique analytical solution of planet and star parameters can be derived from an extrasolar planet transit light curve under a number of assumptions. This analytical solution can be used to choose the best planet transit candidates for radial velocity follow-up measurements, with or without a known spectral type. In practice, high photometric precision (< 0.005 mag) and high time sampling (< 5 minutes) are needed for this method. See Seager & Mallen-Ornelas (2002) for full details.

S. Seager; G. Mallen-Ornelas

2002-10-02

300

Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity  

NASA Astrophysics Data System (ADS)

Context. We have obtained precise radial velocities for a sample of 373 G and K type giants at Lick Observatory regularly over more than 12 years. Planets have been identified around 15 of these giant stars, and an additional 20 giant stars host planet candidates. Aims: We are interested in the occurrence rate of substellar companions around giant stars as a function of stellar mass and metallicity. We probe the stellar mass range from approximately 1 to beyond 3 M?, which is not being explored by main-sequence samples. Methods: We fit the giant planet occurrence rate as a function of stellar mass and metallicity with a Gaussian and an exponential distribution, respectively. Results: We find strong evidence for a planet-metallicity correlation among the secure planet hosts of our giant star sample, in agreement with the one for main-sequence stars. However, the planet-metallicity correlation is absent for our sample of planet candidates, raising the suspicion that a good fraction of them might indeed not be planets despite clear periodicities in the radial velocities. Consistent with the literature results for subgiants, the giant planet occurrence rate increases in the stellar mass interval from 1 to 1.9 M?. However, there is a maximum at a stellar mass of 1.9+ 0.1-0.5 M?, and the occurrence rate drops rapidly for masses larger than 2.5-3.0 M?. We do not find any planets around stars more massive than 2.7 M?, although there are 113 stars with masses between 2.7 and 5 M? in our sample (corresponding to a giant planet occurrence rate smaller than 1.6% at 68.3% confidence in that stellar mass bin). We also show that this result is not a selection effect related to the planet detectability being a function of the stellar mass. Conclusions: We conclude that giant planet formation or inward migration is suppressed around higher mass stars, possibly because of faster disk depletion coupled with a longer migration timescale. Based on observations collected at Lick Observatory, University of California.Table 3 is 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/574/A116

Reffert, Sabine; Bergmann, Christoph; Quirrenbach, Andreas; Trifonov, Trifon; Künstler, Andreas

2015-02-01

301

Classifying Planets: Nature vs. Nurture  

NASA Astrophysics Data System (ADS)

The idea of a planet was so simple when we learned about the solar system in elementary school. Now students and professional s alike are faced with confusing array of definitions --- from "Brown Dwarfs” to "Super Jupiters", from "Super Earths” to "Terrestrial Planets", and from "Planets” to "Small, Sort-of Round Things That Aren't Really Planets". I will discuss how planets might be defined by how they formed, where they are found, or by the life they might support.

Beichman, Charles A.

2009-05-01

302

Possible consequences of absence of "Jupiters" in planetary systems.  

PubMed

The formation of the gas giant planets Jupiter and Saturn probably required the growth of massive approximately 15 Earth-mass cores on a time scale shorter than the approximately 10(7) time scale for removal of nebular gas. Relatively minor variations in nebular parameters could preclude the growth of full-size gas giants even in systems in which the terrestrial planet region is similar to our own. Systems containing "failed Jupiters," resembling Uranus and Neptune in their failure to capture much nebular gas, would be expected to contain more densely populated cometary source regions. They will also eject a smaller number of comets into interstellar space. If systems of this kind were the norm, observation of hyperbolic comets would be unexpected. Monte Carlo calculations of the orbital evolution of region of such systems (the Kuiper belt) indicate that throughout Earth history the cometary impact flux in their terrestrial planet regions would be approximately 1000 times greater than in our Solar System. It may be speculated that this could frustrate the evolution of organisms that observe and seek to understand their planetary system. For this reason our observation of these planets in our Solar System may tell us nothing about the probability of similar gas giants occurring in other planetary systems. This situation can be corrected by observation of an unbiased sample of planetary systems. PMID:11539457

Wetherill, G W

1994-01-01

303

Jupiter Ahoy!  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Annotated Version

The Long Range Reconnaissance Imager (LORRI) on NASA's New Horizons spacecraft took this photo of Jupiter on Sept. 4, 2006, from a distance of 291 million kilometers (nearly 181 million miles) away.

Visible in the image are belts, zones and large storms in Jupiter's atmosphere, as well as the Jovian moons Europa (at left) and Io and the shadows they cast on Jupiter.

LORRI snapped this image during a test sequence to help prepare for the Jupiter encounter observations. It was taken close to solar opposition, meaning that the Sun was almost directly behind the camera when it spied Jupiter. This makes Jupiter appear about 40 times brighter than Pluto will be for LORRI's primary observations when New Horizons encounters the Pluto system in 2015.

To avoid saturation, the camera's exposure time was kept to 6 milliseconds. This image was, in part, a test to see how well LORRI would operate with such a short exposure time.

2007-01-01

304

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

NASA Astrophysics Data System (ADS)

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

Gould, Andrew; Yee, Jennifer C.

2014-03-01

305

Models of the formation of the planets in the 47 UMa system  

E-print Network

Formation of planets in the 47 UMa system is followed in an evolving protoplanetary disk composed of gas and solids. The evolution of the disk is calculated from an early stage, when all solids, assumed to be high-temperature silicates, are in the dust form, to the stage when most solids are locked in planetesimals. The simulation of planetary evolution starts with a solid embryo of ~1 Earth mass, and proceeds according to the core accretion -- gas capture model. Orbital parameters are kept constant, and it is assumed that the environment of each planet is not perturbed by the second planet. It is found that conditions suitable for both planets to form within several Myr are easily created, and maintained throughout the formation time, in disks with $\\alpha \\approx 0.01$. In such disks, a planet of 2.6 Jupiter masses (the minimum for the inner planet of the 47 UMa system) may be formed at 2.1 AU from the star in \\~3 Myr, while a planet of 0.89 Jupiter masses (the minimum for the outer planet) may be formed at 3.95 AU from the star in about the same time. The formation of planets is possible as a result of a significant enhancement of the surface density of solids between 1.0 and 4.0 AU, which results from the evolution of a disk with an initially uniform gas-to-dust ratio of 167 and an initial radius of 40 AU.

Kacper Kornet; Peter Bodenheimer; Michal Rozyczka

2002-09-30

306

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

SciTech Connect

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

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

2011-11-01

307

Examining the Relative Compositions of Giant Planets and their Parent Stars  

NASA Astrophysics Data System (ADS)

Observational knowledge of the connection between giant planet compositions and their parent stars' metal abundances is limited. These planets appear consistently enriched, but the sample size is small -- only our solar system and a handful of transiting extrasolar planets. Understanding this relationship in uninflated planets could help in constraining the inflationary mechanism in hotter planets. Thus, we consider a population of nearly 40 transiting massive planets which have sufficiently low insolation that they are not inflated. Using thermal evolution models, we determine their bulk metallicity Z_planet from their mass, radius, and age. Comparing this against parent star metal enrichment Z_star, which we derive from the iron abundance [Fe/H], we note a number of patterns. We see a previously suggested minimum metal content at ~10 earth masses, as well as a strong negative negative correlation in enrichment (Z_planet / Z_star) against planet mass. This can be used to give constraints on planet formation and population synthesis models. This metal relative enrichment is even seen up to ~10 Jupiter masses, around the brown dwarf transition mass, which represents an observational difference between very massive planets and low-mass brown dwarfs.

Thorngren, Daniel; Fortney, Jonathan J.

2015-01-01

308

Far-infrared spectroscopy of the giant planets: measurements of ammonia and phosphine at Jupiter and Saturn and the continuum of Neptune  

Microsoft Academic Search

We detected rotational transition features of ammonia and phosphine in the far-infrared spectra of Jupiter and Saturn and measured the far-infrared continuum of Neptune with high photometric accuracy. These observations were made with the long-wavelength spectrometer (LWS) aboard the infrared space observatory (ISO). The LWS covered the wavelength region between 43 and 197 mum (51-233 cm-1) with both medium and

M. J. Burgdorf; G. S. Orton; T. Encrenaz; G. R. Davis; E. Lellouch; S. D. Sidher; B. M. Swinyard

2004-01-01

309

Far-infrared spectroscopy of the giant planets: measurements of ammonia and phosphine at Jupiter and Saturn and the continuum of Neptune  

Microsoft Academic Search

We detected rotational transition features of ammonia and phosphine in the far-infrared spectra of Jupiter and Saturn and measured the far-infrared continuum of Neptune with high photometric accuracy. These observations were made with the long-wavelength spectrometer (LWS) aboard the infrared space observatory (ISO). The LWS covered the wavelength region between 43 and 197 ?m (51–233 cm?1) with both medium and

M. J. Burgdorf; G. S. Orton; T. Encrenaz; G. R. Davis; E. Lellouch; S. D. Sidher; B. M. Swinyard

2004-01-01

310

A Sub-Saturn Mass Planet, MOA2009-BLG-319Lb  

Microsoft Academic Search

We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K- or M-dwarf star in the inner Galactic disk or Galactic bulge. The high-cadence observations of the MOA-II survey discovered this microlensing event and enabled its identification as a high-magnification event approximately 24 hr prior to peak magnification. As a result, the planetary signal at the

N. Miyake; T. Sumi; Subo Dong; L. Mancini; A. Gould; D. P. Bennett; Y. Tsapras; J. C. Yee; M. D. Albrow; I. A. Bond; P. Fouqué; P. Browne; C. Han; C. Snodgrass; F. Finet; K. Furusawa; K. Harpsøe; W. Allen; M. Hundertmark; M. Freeman; D. Suzuki; F. Abe; C. S. Botzler; D. Douchin; A. Fukui; F. Hayashi; J. B. Hearnshaw; S. Hosaka; Y. Itow; K. Kamiya; P. M. Kilmartin; A. Korpela; W. Lin; C. H. Ling; S. Makita; K. Masuda; Y. Matsubara; Y. Muraki; T. Nagayama; K. Nishimoto; K. Ohnishi; Y. C. Perrott; N. Rattenbury; To. Saito; L. Skuljan; D. J. Sullivan; W. L. Sweatman; P. J. Tristram; K. Wada; P. C. M. Yock; G. Bolt; M. Bos; G. W. Christie; D. L. DePoy; J. Drummond; A. Gal-Yam; B. S. Gaudi; E. Gorbikov; D. Higgins; K.-H. Hwang; J. Janczak; S. Kaspi; C.-U. Lee; J.-R. Koo; S. Kozlowski; Y. Lee; F. Mallia; A. Maury; D. Maoz; J. McCormick; L. A. G. Monard; D. Moorhouse; J. A. Muñoz; T. Natusch; E. O. Ofek; R. W. Pogge; D. Polishook; R. Santallo; A. Shporer; O. Spector; G. Thornley; A. Allan; D. M. Bramich; K. Horne; N. Kains; I. Steele; V. Bozza; M. J. Burgdorf; S. Calchi Novati; M. Dominik; S. Dreizler; M. Glitrup; F. V. Hessman; T. C. Hinse; U. G. Jørgensen; C. Liebig; G. Maier; M. Mathiasen; S. Rahvar; D. Ricci; G. Scarpetta; J. Skottfelt; J. Southworth; J. Surdej; J. Wambsganss; F. Zimmer; V. Batista; J. P. Beaulieu; S. Brillant; A. Cassan; A. Cole; E. Corrales; Ch. Coutures; S. Dieters; J. Greenhill; D. Kubas; J. Menzies

2011-01-01

311

Simulations of Gaseous Disc-Embedded Planet Interaction  

E-print Network

We present three-dimensional self-gravitating smoothed-particle hydrodynamics (SPH) simulations of an isothermal gaseous disc interacting with an embedded planet. Discs of varying stability are simulated with planets ranging from 10 Earth-masses to 2 Jupiter-masses. The SPH technique provides the large dynamic range needed to accurately capture the large scale behavior of the disc as well as the small scale interaction of the planet with surrounding material. Most runs used 10^5 gas particles, giving us the spatial resolution required to observe the formation of planets. We find four regions in parameter space: low-mass planets undergo Type I migration; higher-mass planets can form a gap; the gravitational instability mode of planet formation in marginally stable discs can be triggered by embedded planets; discs that are completely unstable can fragment to form many planets. The disc stability is the most important factor in determing which interaction a system will exhibit. For the stable disc cases, our migration and accretion time-scales are shorter and scale differently than previously suggested.

Graeme Lufkin; Thomas Quinn; James Wadsley; Joachim Stadel; Fabio Governato

2003-05-28

312

Gaia's potential for the discovery of circumbinary planets  

NASA Astrophysics Data System (ADS)

The abundance and properties of planets orbiting binary stars - circumbinary planets - are largely unknown because they are difficult to detect with currently available techniques. Results from the Kepler satellite and other studies indicate a minimum occurrence rate of circumbinary giant planets of ˜10 per cent, yet only a handful are presently known. Here, we study the potential of ESA's Gaia mission to discover and characterize extrasolar planets orbiting nearby binary stars by detecting the binary's periodic astrometric motion caused by the orbiting planet. We expect that Gaia will discover hundreds of giant planets around binaries with FGK-dwarf primaries within 200 pc of the Sun, if we assume that the giant planet mass distribution and abundance are similar around binaries and single stars. If on the other hand all circumbinary gas giants have masses lower than two Jupiter masses, we expect only four detections. Gaia is critically sensitive to the properties of giant circumbinary planets and will therefore make the detailed study of their population possible. Gaia's precision is such that the distribution in mutual inclination between the binary and planetary orbital planes will be obtained. It also possesses the capacity to establish the frequency of planets across the Hertzsprung-Russell diagram, both as a function of mass and of stellar evolutionary state from pre-main sequence to stellar remnants. Gaia's discoveries can reveal whether a second epoch of planetary formation occurs after the red giant phase.

Sahlmann, J.; Triaud, A. H. M. J.; Martin, D. V.

2015-02-01

313

AN ULTRACOOL STAR'S CANDIDATE PLANET  

SciTech Connect

We report here the discovery of the first planet around an ultracool dwarf star. It is also the first extrasolar giant planet astrometrically discovered around a main-sequence star. The statistical significance of the detection is shown in two ways. First, there is a 2 x 10{sup -8} probability that the astrometric motion fits a parallax-and-proper-motion-only model. Second, periodogram analysis shows a false alarm probability of 3 x 10{sup -5} that the discovered period is randomly generated. The planetary mass is M {sub 2} = 6.4 (+2.6,-3.1) Jupiter-masses (M {sub J}), and the orbital period is P = 0.744 (+0.013,-0.008) yr in the most likely model. In less likely models, companion masses that are higher than the 13 M {sub J} planetary mass limit are ruled out by past radial velocity (RV) measurements unless the system RV is more than twice the current upper limits and the near-periastron orbital phase was never observed. This new planetary system is remarkable, in part, because its star, VB 10, is near the lower mass limit for a star. Our astrometric observations provide a dynamical mass measurement and will in time allow us to confront the theoretical models of formation and evolution of such systems and their members. We thus add to the diversity of planetary systems and to the small number of known M-dwarf planets. Planets such as VB 10b could be the most numerous type of planets because M stars comprise >70% of all stars. To date they have remained hidden since the dominant RV planet-discovery technique is relatively insensitive to these dim, red systems.

Pravdo, Steven H. [Jet Propulsion Laboratory, California Institute of Technology, 306-431, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Shaklan, Stuart B. [Jet Propulsion Laboratory, California Institute of Technology, 301-451, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)], E-mail: spravdo@jpl.nasa.gov, E-mail: stuart.shaklan@jpl.nasa.gov

2009-07-20

314

On Approach: Jupiter and Io  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for movie of On Approach: Jupiter and Io

This sequence of images was taken on Jan. 8, 2007, with the New Horizons Long Range Reconnaissance Imager (LORRI), while the spacecraft was about 81 million kilometers (about 50 million miles) from Jupiter. Jupiter's volcanic moon Io is to the right; the planet's Great Red Spot is also visible. The image was one of 11 taken during the Jan. 8 approach sequence, which signaled the opening of the New Horizons Jupiter encounter.

Even in these early approach images, Jupiter shows different face than what previous visiting spacecraft -- such as Voyager 1, Galileo and Cassini -- have seen. Regions around the equator and in the southern tropical latitudes seem remarkably calm, even in the typically turbulent 'wake' behind the Great Red Spot.

The New Horizons science team will scrutinize these major meteorological features -- including the unexpectedly calm regions -- to understand the diverse variety of dynamical processes on the solar system's largest planet. These include the newly formed Little Red Spot, the Great Red Spot and a variety of zonal features.

2007-01-01

315

Jupiter: Internal Dynamics and Shape  

NASA Astrophysics Data System (ADS)

The physical shape of a giant planet reveals important information about its rotation and internal structure. We investigate how differential rotation on cylinders affects Jupiter's shape. We project Jupiter's measured zonal wind velocities along cylinders to describe its centrifugal potential which is then used to derive Jupiter's shape using an equipotential surface theory. The derived shape for different cylindrical radii is then compared with Jupiter's shape from radio occultation measurements. It is found that both solid-body rotation (System III rotation rate) and differential rotation up to a latitude of ~ 20-30 degrees are consistent with Jupiter's measured shape. We next use a first-order theory that relates the second gravitational coefficient J_2 to the flattening to calculate the corrections to J_2 for the different rotational configurations. We find that the contribution of the flattening to J_2 is significant. We therefore suggest that interior models of the giant planets must account for J_2n corrections caused by both shape (flattening) and internal dynamics.

Helled, R.; Schubert, G.; Anderson, J. D.

2011-12-01

316

A HOT JUPITER ORBITING THE 1.7 M {sub sun} SUBGIANT HD 102956  

SciTech Connect

We report the detection of a giant planet in a 6.4950 day orbit around the 1.68 M {sub sun} subgiant HD 102956. The planet has a semimajor axis a = 0.081 AU and a minimum mass M{sub P} sin i =0.96 M {sub Jup}. HD 102956 is the most massive star known to harbor a hot Jupiter, and its planet is only the third known to orbit within 0.6 AU of a star more massive than 1.5 M {sub sun}. Based on our sample of 137 subgiants with M {sub *}>1.45 M {sub sun}, we find that 0.5%-2.3% of A-type stars harbor a close-in planet (a < 0.1 AU) with M{sub P} sin i > 1 M {sub Jup}, consistent with hot-Jupiter occurrence for Sun-like stars. Thus, the paucity of planets with 0.1 AU < a < 1.0 AU around intermediate-mass stars may be an exaggerated version of the 'period valley' that is characteristic of planets around Sun-like stars.

Johnson, John Asher; Morton, Timothy D.; Crepp, Justin R. [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Bowler, Brendan P. [Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Howard, Andrew W.; Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Mail Code 3411, Berkeley, CA 94720 (United States); Henry, Gregory W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Blvd., Box 9501, Nashville, TN 37209 (United States); Brewer, John Michael; Fischer, Debra A., E-mail: johnjohn@astro.caltech.ed [Department of Astronomy, Yale University, New Haven, CT 06511 (United States)

2010-10-01

317

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

E-print Network

The ubiquity of planets poses an interesting question: when first planets are formed in galaxies. We investigate this problem by adopting a theoretical model developed for understanding the statistical properties of exoplanets. Our model is constructed as the combination of planet traps with the standard core accretion scenario in which the efficiency of forming planetary cores directly relates to the dust density in disks or the metallicity ([Fe/H]). We statistically compute planet formation frequencies (PFFs) as well as the orbital radius ($$) within which gas accretion becomes efficient enough to form Jovian planets. The three characteristic exoplanetary populations are considered: hot Jupiters, exo-Jupiters densely populated around 1 AU, and low-mass planets such as super-Earths. We explore the behavior of the PFFs as well as $$ for the three different populations as a function of metallicity ($-2 \\leq$[Fe/H]$\\leq -0.6$). We show that the total PFFs increase steadily with metallicity, which is the direct ...

Hasegawa, Yasuhiro

2014-01-01

318

Microlensing limits on numbers and orbits of extrasolar planets from the 1998-2000 OGLE events  

Microsoft Academic Search

We analyse three years (1998-2000) of Optical Gravitational Lensing Experiment (OGLE) observations of microlensing events to place limits on the abundance of planets with a planet-to-star mass ratio q= 10-3 at distances ~1-4 au from their host stars, i.e. `cool Jupiters'. We fit a total of 145 events using a maximum-likelihood fit that adjusts six parameters. Each data point on

Yiannis Tsapras; Keith Horne; Stephen Kane; Richard Carson

2003-01-01

319

Bayesian search for low-mass planets around nearby M dwarfs - estimates for occurrence rate based on global detectability statistics  

NASA Astrophysics Data System (ADS)

Due to their higher planet-star mass ratios, M dwarfs are the easiest targets for detection of low-mass planets orbiting nearby stars using Doppler spectroscopy. Furthermore, because of their low masses and luminosities, Doppler measurements enable the detection of low-mass planets in their habitable zones that correspond to closer orbits than for solar-type stars. We re-analyse literature Ultraviolet and Visual Echelle Spectrograph (UVES) radial velocities of 41 nearby M dwarfs in a combination with new velocities obtained from publicly available spectra from the HARPS-ESO spectrograph of these stars in an attempt to constrain any low-amplitude Keplerian signals. We apply Bayesian signal detection criteria, together with posterior sampling techniques, in combination with noise models that take into account correlations in the data and obtain estimates for the number of planet candidates in the sample. More generally, we use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. We report eight new planet candidates in the sample (orbiting GJ 27.1, GJ 160.2, GJ 180, GJ 229, GJ 422, and GJ 682), including two new multiplanet systems, and confirm two previously known candidates in the GJ 433 system based on detections of Keplerian signals in the combined UVES and High Accuracy Radial velocity Planet Searcher (HARPS) radial velocity data that cannot be explained by periodic and/or quasi-periodic phenomena related to stellar activities. Finally, we use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. According to our results, M dwarfs are hosts to an abundance of low-mass planets and the occurrence rate of planets less massive than 10 M? is of the order of one planet per star, possibly even greater. Our results also indicate that planets with masses between 3 and 10 M? are common in the stellar habitable zones of M dwarfs with an estimated occurrence rate of 0.21^{+0.03}_{-0.05} planets per star.

Tuomi, Mikko; Jones, Hugh R. A.; Barnes, John R.; Anglada-Escudé, Guillem; Jenkins, James S.

2014-06-01

320

Revised version: Dec 20, 2001 On the Nature of Stars with Planets  

E-print Network

System are starting to emerge amongst the most recent discoveries (Vogt et al., 2001). Thus: planetary systems: formation; Galaxy: stellar content 1. Introduction The discovery of the first extrasolar resemblance to our own Solar System: 51 Pegasi­like systems feature `hot jupiters', Jovian­mass planets in sub

Reid, Iain Neill

321

From Hot Jupiters to Super-Earths via Roche Lobe Overflow  

NASA Astrophysics Data System (ADS)

Through tidal dissipation in a slowly spinning host star, the orbits of many hot Jupiters may decay down to the Roche limit. We expect that the ensuing mass transfer will be stable in most cases. Using detailed numerical calculations, we find that this evolution is quite rapid, potentially leading to the complete removal of the gaseous envelope in a few gigayears, and leaving behind an exposed rocky core (a "hot super-Earth"). Final orbital periods are quite sensitive to the details of the planet's mass-radius relation and to the effects of irradiation and photo-evaporation, but could be as short as a few hours or as long as several days. Our scenario predicts the existence of planets with intermediate masses ("hot Neptunes") that should be found precisely at their Roche limit and in the process of losing mass through Roche lobe overflow. The observed excess of small single-planet candidate systems observed by Kepler may also be the result of this process. If so, the properties of their host stars should track those of the hot Jupiters. Moreover, the number of systems that produced hot Jupiters could be two to three times larger than one would infer from contemporary observations.

Valsecchi, Francesca; Rasio, Frederic A.; Steffen, Jason H.

2014-09-01

322

Galileo Probe Mass Spectrometer Measurements of the Chemical Composition of the Atmosphere of Jupiter  

Microsoft Academic Search

The chemical and isotopic composition of the Jovian atmosphere was measured by the Galileo Probe Mass Spectrometer (GPMS). This data was obtained on December 7, 1995 over a time period of approximately 1 hour during the probe descent in the 0.5 to 20 bar pressure region and transmitted to Earth over a period of several weeks. The sampling was either

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

1996-01-01

323

Auroral ultraviolet darkening on the outer planets  

SciTech Connect

The Voyager 2 Photopolarimeter Subsystem (PPS) has made photometric observations of Jupiter at 2400 A and photometric and polarimetric observations of Saturn and Uranus at 2650 A. At these wavelengths the instrument is observing each planet's stratosphere and upper troposphere. The most striking features are that both poles of Jupiter and the observed northern pole of Saturn are very dark, while Uranus has a uniformly bright appearance. All three planets show evidence for a stratospheric haze. Simple vertically homogeneous multiple scattering models are used to characterize these stratospheric hazes. Aurores occur at high latitudes on Jupiter and Saturn and at low latitudes on Uranus. The asymmetric polar darkening on Jupiter seen by PPS is roughly matched by the asymmetry in the auroral zones. Historical data suggest that the haze asymmetry is persistent. The dark north polar cap seen by PPS at Saturn is small and close to the pole, which corresponds to the small auroral zone close to the pole. A model is examined which attributes the darkening to auroral bombardment initiating methane chemistry that makes dark hydrocarbon particles. Possible chemical pathways are discussed, and mass balance calculations are presented for Jupiter, Saturn, and Uranus. The model is quantitatively plausible for Jupiter and Saturn. The lack of localized darkening on Uranus can be explained in this model by noting that weak vertical mixing and methane condensation near the 1-bar level lead to negligible methane abundances at auroral altitudes. The auroras must reach the methane for dark material to form. The thin haze that is seen on Uranus is ascribed to photochemical processes. Voyager 2 will reach Neptune this year. Ground-based observers have reported vigorous vertical mixing and large amounts of stratospheric methane there.

Pryor, W.R.

1989-01-01

324

Identifying wide, cold planets within 8pc  

NASA Astrophysics Data System (ADS)

Direct imaging exoplanet studies have recently unveiled a previously-unexpected population of massive planets (up to 15 M_Jup) in wide orbits (>100AU). Although most of these discoveries have been around younger stars and have been of similar temperatures to field brown dwarfs, one object (WD 0806-661B), is the coldest planet known outside our solar system. We propose a survey of all stars and brown dwarfs within 8pc to identify massive planetary companions in the 150-1500AU separation range. We will 1) Measure the fraction of wide planetary mass companions to stars in the Solar neighbourhood. 2) Identify all planets within 8 parsecs with masses above 8 Jupiter masses in our chosen projected separation range with lower mass limits for closer and younger stars. 3) Identify approximately 8 planets, four of which will have temperatures below 300K making them ideal targets to study water clouds in cold atmospheres with both JWST and the next generation of ground-based extremely large telescopes. Our survey will be the most complete survey for wide planets to-date and will provide both a measurement of the wide planet population and a legacy of cold, well constrained targets for future observatories.

Deacon, Niall; Kraus, Adam; Crossfield, Ian

2014-12-01

325

Create Your Own Planet  

NSDL National Science Digital Library

In this project you will be the creator of a new planet in our solar system. You will be free to decide all of the characteristics of your planet. Look at the different websites below to find out more about the planets in our solar system and then decide what characteristics your planet will have. PLANET PICTURES AND FACTS I I I I I V Mercury Facts Venus Facts Earth Facts Mars Facts Jupiter Facts Saturn Facts Uranus Facts Neptune Facts PROJECT REQUIREMENTS: Your planet must have one moon or more. You must decide how long it takes your planet to rotate (length of a day on your planet). You must decide how long it takes your planet to ...

Mr. Larsen

2008-11-25

326

Comets and the formation of planets  

NASA Technical Reports Server (NTRS)

Morphological study of the physical and dynamical processes of planet formation, with emphasis on the role of comet nuclei. A consistent model proposes the formation of comets and planets in preplanetary rings of the residual solar nebula, with subsequent ejection, chiefly by Jupiter, of the comets to Oort's (1950) sphere. Physically, dynamically, or statistically evaluated items include: (1) the total number and mass of comets in Oort's cloud; (2) reevaluation of the diameters and masses of comet nuclei; (3) the processes of nucleation from gravitational and 'Boltzmann' instabilities of gaseous media to agglomerations of particulate matter; and (4) the statistical-dynamical conditions and time scales of orbital interaction of comets with the planets and the consequences of disintegration.

Opik, E. J.

1973-01-01

327

Jupiter's Rings  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Annotated Version

The New Horizons Long Range Reconnaissance Imager (LORRI) snapped this photo of Jupiter's ring system on February 24, 2007, from a distance of 7.1 million kilometers (4.4 million miles).

This processed image shows a narrow ring, about 1,000 kilometers (600 miles) wide, with a fainter sheet of material inside it. The faint glow extending in from the ring is likely caused by fine dust that diffuses in toward Jupiter. This is the outer tip of the 'halo,' a cloud of dust that extends down to Jupiter's cloud tops. The dust will glow much brighter in pictures taken after New Horizons passes to the far side of Jupiter and looks back at the rings, which will then be sunlit from behind.

Jupiter's ring system was discovered in 1979, when astronomers spied it in a single image taken by the Voyager 1 spacecraft. Months later, Voyager 2 carried out more extensive imaging of the system. It has since been examined by NASA's Galileo and Cassini spacecraft, as well as by the Hubble Space Telescope and large ground-based observatories.

2007-01-01

328

A Strange New Planet  

NSDL National Science Digital Library

Scientists have been looking for extra-solar planets for decades, but only recently, with better equipment and improved techniques, have they finally unveiled new and unusual planets. Since 1995, over 155 planets have been discovered orbiting stars other than our Sun. This video segment, adapted from a NOVA television broadcast, gives an account of the discovery of the first confirmed extra-solar planet, a Jupiter-sized giant orbiting the star 51 Pegasi, and discusses the search for other extra-solar planets. The segment is three minutes nine seconds in length.

329

A Strange New Planet  

NSDL National Science Digital Library

Scientists have been looking for extra-solar planets for decades, but only recently, with better equipment and improved techniques, have they finally unveiled new and unusual planets. Since 1995, over 155 planets have been discovered orbiting stars other than our Sun. This video segment, adapted from a NOVA television broadcast, gives an account of the discovery of the first confirmed extra-solar planet, a Jupiter-sized giant orbiting the star 51 Pegasi, and discusses the search for other extra-solar planets. The segment is three minutes nine seconds in length.

2011-05-05

330

Colliding Winds in Low-Mass Binary Star Systems: wind interactions and implications for habitable planets  

E-print Network

Context. In binary star systems, the winds from the two components impact each other, leading to strong shocks and regions of enhanced density and temperature. Potentially habitable circumbinary planets must continually be exposed to these interactions regions. Aims. We study, for the first time, the interactions between winds from low-mass stars in a binary system, to show the wind conditions seen by potentially habitable circumbinary planets. Methods. We use the advanced 3D numerical hydrodynamic code Nurgush to model the wind interactions of two identical winds from two solar mass stars with circular orbits and a binary separation of 0.5 AU. As input into this model, we use a 1D hydrodynamic simulation of the solar wind, run using the Versatile Advection Code. We derive the locations of stable and habitable orbits in this system to explore what wind conditions potentially habitable planets will be exposed to during their orbits. Results. Our wind interaction simulations result in the formation of two stron...

Johnstone, C P; Pilat-Lohinger, E; Bisikalo, D; Güdel, M; Eggl, S

2015-01-01

331

Jupiter's obliquity and a long-lived circumplanetary disk  

NASA Astrophysics Data System (ADS)

It has been claimed [Canup, R.M., Ward, W.R., 2002. Astron. J. 124, 3404-3423; Ward, W.R., 2003. In: AGU, Fall Meeting 2003] that a long-lived minimum mass circumplanetary gas disk is inconsistent with Jupiter's low obliquity. Here we find that while Jupiter's obliquity may constrain its characteristics it does not rule out a long-lived massive (compared to the mass of the Galilean satellites) disk. This is because the argument assumes a Solar System much like that of the present day with the one exception of a circumjovian disk which is then allowed to dissipate on a long timescale ( 10-10 yr). Given that the sequence of events in Solar System history that fit known constraints is non-unique, we choose for the sake of clarity of exposition the orbital architecture framework of Tsiganis et al. [Tsiganis, K., Gomes, R., Morbidelli, A., Levison, H.F., 2005. Nature 435, 459-461], in which Jupiter and Saturn were once in compact, nearly coplanar orbits, and show that in this case Jupiter's low obliquity is consistent with the SEMM (solids-enhanced minimum mass) satellite formation model of Mosqueira and Estrada [Mosqueira, I., Estrada, P.R., 2003a. Icarus 163, 198-231; Mosqueira, I., Estrada, P.R., 2003b. Icarus 163, 232-255]. We suggest that a low inclination starting condition may apply, but stress that our SEMM satellite formation model could be compatible with Jupiter's obliquity even for mutually inclined giant planets.

Mosqueira, Ignacio; Estrada, Paul R.

2006-01-01

332

70 Days of Jupiter Winds  

NASA Technical Reports Server (NTRS)

This global movie of 70 days of Jupiter's cloud movements photographed by NASA's Cassini spacecraft shows that zones of eastward and westward winds cover the planet virtually from pole to pole.

Cassini's narrow-angle camera captured the images of Jupiter's atmosphere from October 1 to December 9, 2000, in the near-infrared region of the spectrum. The view here is a cylindrical projection centered in the planet's equator.

The movie allows tracking of individual storms' movements in the familiar zonal bands of the lower latitudes, in the swirling turbulence around the Great Red Spot and in the high latitudes where still images show chaotic mottling instead of stripes.

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. Six 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 70Earth days in time or 168 Jupiter rotations.

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

333

ESTIMATES OF THE PLANET YIELD FROM GROUND-BASED HIGH-CONTRAST IMAGING OBSERVATIONS AS A FUNCTION OF STELLAR MASS  

SciTech Connect

We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into consideration the important factors that govern the likelihood for imaging a planet, including the statistical properties of stars in the solar neighborhood, correlations between star and planet properties, observational effects, and selection criteria. We consider several different ground-based surveys, both biased and unbiased, and express the resulting planet yields as a function of stellar mass. Selecting targets based on their youth and visual brightness, we find that strong correlations between star mass and planet properties are required to reproduce high-contrast imaging results to date (i.e., HR 8799, {beta} Pic). Using the most recent empirical findings for the occurrence rate of gas-giant planets from radial velocity (RV) surveys, our simulations indicate that naive extrapolation of the Doppler planet population to semimajor axes accessible to high-contrast instruments provides an excellent agreement between simulations and observations using present-day contrast levels. In addition to being intrinsically young and sufficiently bright to serve as their own beacon for adaptive optics correction, A-stars have a high planet occurrence rate and propensity to form massive planets in wide orbits, making them ideal targets. The same effects responsible for creating a multitude of detectable planets around massive stars conspire to reduce the number orbiting low-mass stars. However, in the case of a young stellar cluster, where targets are approximately the same age and situated at roughly the same distance, MK-stars can easily dominate the number of detections because of an observational bias related to small number statistics. The degree to which low-mass stars produce the most planet detections in this special case depends upon whether multiple formation mechanisms are at work. Upon relaxing our assumption that planets in ultra-wide (a > 100 AU) orbits resemble the RV sample, our simulations suggest that the companions found orbiting late-type stars (AB Pic, 1RXSJ1609, GSC 06214, etc.) are consistent with a formation channel distinct from that of RV planets. These calculations explain why planets have thus far been imaged preferentially around A-stars and K-, M-stars, but no spectral types in between, despite concerted efforts targeting F-, G-stars.

Crepp, Justin R.; Johnson, John Asher, E-mail: jcrepp@astro.caltech.edu [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); NASA Exoplanet Science Institute (NExScI), California Institute of Technology, Mail Code 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States)

2011-06-01

334

Estimates of the Planet Yield from Ground-based High-contrast Imaging Observations as a Function of Stellar Mass  

NASA Astrophysics Data System (ADS)

We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into consideration the important factors that govern the likelihood for imaging a planet, including the statistical properties of stars in the solar neighborhood, correlations between star and planet properties, observational effects, and selection criteria. We consider several different ground-based surveys, both biased and unbiased, and express the resulting planet yields as a function of stellar mass. Selecting targets based on their youth and visual brightness, we find that strong correlations between star mass and planet properties are required to reproduce high-contrast imaging results to date (i.e., HR 8799, ? Pic). Using the most recent empirical findings for the occurrence rate of gas-giant planets from radial velocity (RV) surveys, our simulations indicate that naive extrapolation of the Doppler planet population to semimajor axes accessible to high-contrast instruments provides an excellent agreement between simulations and observations using present-day contrast levels. In addition to being intrinsically young and sufficiently bright to serve as their own beacon for adaptive optics correction, A-stars have a high planet occurrence rate and propensity to form massive planets in wide orbits, making them ideal targets. The same effects responsible for creating a multitude of detectable planets around massive stars conspire to reduce the number orbiting low-mass stars. However, in the case of a young stellar cluster, where targets are approximately the same age and situated at roughly the same distance, MK-stars can easily dominate the number of detections because of an observational bias related to small number statistics. The degree to which low-mass stars produce the most planet detections in this special case depends upon whether multiple formation mechanisms are at work. Upon relaxing our assumption that planets in ultra-wide (a > 100 AU) orbits resemble the RV sample, our simulations suggest that the companions found orbiting late-type stars (AB Pic, 1RXSJ1609, GSC 06214, etc.) are consistent with a formation channel distinct from that of RV planets. These calculations explain why planets have thus far been imaged preferentially around A-stars and K-, M-stars, but no spectral types in between, despite concerted efforts targeting F-, G-stars.

Crepp, Justin R.; Johnson, John Asher

2011-06-01

335

Giant Planet Accretion in a Low-Turbulence Circumplanetary Disk  

NASA Astrophysics Data System (ADS)

At least 5% of confirmed planets discovered by the Kepler Mission have a mass greater than Jupiter's. Gas giants more massive than Saturn account for at least 18% of all confirmed planets.The final stages of gas accretion of a giant planet occur in the presence of a circumplanetary disk (CPD). Recently, it was proposed that turbulence (and hence transport) in these disks is driven by MRI, possibly generating low-turbulence regions known as Dead Zones. It was thus suggested that gas accretion through a CPD and on the planet can be severely reduced by a Dead Zone. If CPDs create a bottleneck for the accretion of gas, then the growth of planets more massive than Jupiter may become problematic.We investigate how gas accretion on a Jupiter-mass planet is affected by a Dead Zone by means of global 3D hydrodynamics calculations. We model both the CPD and the protoplanetary disk. The accretion flow is resolved at a length scale smaller than Jupiter's radius, Rj, by using a nested-grid technique. We assume that the kinematic viscosity is constant and equal to nu=1e-5 Omega a^2, where a and Omega are respectively the planet's orbital radius and frequency. A Dead Zone around the planet is represented by a region of low viscosity (nu=1e-8 Omega a^2), extending out to ~60Rj and above and below the CPD mid-plane for a few local scale heights. We obtain an accretion rate of ~5e-5 Omega Sigma a^2, where Sigma is the unperturbed protoplanetary disk density. Calculations by D'Angelo et al. (2003) and Bate et al. (2003), which used nu=1e-5 Omega a^2 everywhere but applied a much coarser resolution and different accretion parameters, found an accretion rate of ~2e-4 Omega Sigma a^2. Accounting for variations of several tens of percent, arising from differences (between these and previous calculations) in numerical parameters and resolution, we argue that a CPD Dead Zone, as modeled here, does not significantly affect the gas accretion rate of a giant planet. This result is compatible with several previous studies, which found that the accretion flow involves mostly gas at and above the CPD surface. Continued accretion in the presence of a CPD is also consistent with observed exoplanets several times more massive than Jupiter.

D'Angelo, Gennaro; Marzari, Francesco

2014-06-01

336

Kepler Mission to Detect Earth-like Planets  

NASA Technical Reports Server (NTRS)

Kepler Mission to detect Earth-like planets in our Milky Way galaxy was approved by NASA in December 2001 for a 4-5 year mission. The launch is planned in about 5 years. The Kepler observatory will be placed in an Earth-trailing orbit. The unique feature of the Kepler Mission is its ability to detect Earth-like planets orbiting around solar-type stars at a distance similar to that of Earth (from our Sun); such an orbit could provide an environment suitable for supporting life as we know it. The Kepler observatory accomplishes this feat by looking for the transits of planetary object in front of their suns; Kepler has a photometric precision of 10E-5 (0.00001) to achieve such detections. Other ongoing planetary detection programs (based mostly on a technique that looks for the shifting of spectral lines of the primary star due to its planetary companions' motions around it) have detected massive planets (with masses in the range of Jupiter); such massive planets are not considered suitable for supporting life. If our current theories for the formation of planetary systems are valid, we expect to detect about 50 Earth-like planets during Kepler's 4-year mission (assuming a random distribution of the planetary orbital inclinations with respect to the line of sight from Kepler). The number of detection will increase about 640 planets if the planets to be detected are Jupiter-sized.

Kondo, Yoji

2003-01-01

337

Kepler Mission to Detect Earth-like Planets  

NASA Technical Reports Server (NTRS)

Kepler Mission to detect Earth-like planets in our Milky Way galaxy was approved by NASA in December 2001 for a 4-5 year mission. The launch is planned in about 5 years. The Kepler observatory will be placed in an Earth-trailing orbit. The unique feature of the Kepler Mission is its ability to detect Earth-like planets orbiting around solar-type stars at a distance similar to that of Earth (from our Sun); such an orbit could provide an environment suitable for supporting life as we know it. The Kepler observatory accomplishes this feat by looking for the transits of planetary object in front of their suns; Kepler has a photometric precision of 10E-5 (0.00001) to achieve such detections. Other ongoing planetary detection programs (based mostly on a technique that looks for the shifting of spectral lines of the primary star due to its planetary companions' motions around it) have detected massive planets (with masses in the range of Jupiter); such massive planets are not considered suitable for supporting life. If our current theories for the formation of planetary systems are valid, we expect to detect about 50 Earth-like planets during Kepler's 4-year mission (assuming a random distribution of the planetary orbital inclinations with respect to the line of sight from Kepler). The number of detection will increase about 640 planets if the planets to be detected are Jupiter-sized.

Kondo, Yoji

2002-01-01

338

Jupiter's Main Ring  

NASA Technical Reports Server (NTRS)

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow. Some radial structure is barely visible across the ring's ansa. A faint mist of particles can be seen above and below the main rings; this vertically extended 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces pushing the smallest grains out of the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic.

Jupiter's main ring is a thin strand of material encircling the planet. The diffuse innermost boundary begins at approximately 123,000 km. The main ring's outer radius is found to be at 128,940 +/-50 km, slightly less than the Voyager value of 129,130 +/-100 km, but very close to the orbit of the satellite Adrastea (128,980 km). The main ring exhibits a marked drop in brightness at 127,849 +/-50 km, lying almost atop the orbit of the Jovian moon Metis at 127,978 km. Satellites seem to affect the structure of even tenuous rings like that found at Jupiter.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at: http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.

1997-01-01

339

Migration of massive planets in accreting disks  

NASA Astrophysics Data System (ADS)

Aims: Massive planets that open a gap in the accretion disk are believed to migrate with exactly the viscous speed of the disk, a regime termed type II migration. Population synthesis models indicate that standard type II migration is too rapid to be in agreement with the observations. We study the migration of massive planets between 2 × 10-4 and 2 × 10-3 M?, corresponding to 0.2 to 2 Jupiter masses MJ to estimate the migration rate in comparison to type II migration. Methods: We follow the evolution of planets embedded in two-dimensional, locally isothermal disks with non-zero mass accretion, which is explicitly modelled using suitable in- and outflow boundary conditions to ensure a specific accretion rate. After a certain relaxation time we release the planet and measure its migration through the disk and the dependence on parameters, such as viscosity, accretion rate, and planet mass. We study accreting and non-accretion planets. Results: The inferred migration rate of the planet is determined entirely by the disk torques acting on it and is completely independent of the viscous inflow velocity, so there is no classical type II migration regime. Depending on the local disk mass, the migration rate can be faster or slower than type II migration. From the torques and the accretion rate profile in the disk we see that the gap formed by the planet does not separate the inner from the outer disk as necessary for type II migration, rather gas crosses the gap or is accreted onto the planet.

Dürmann, C.; Kley, W.

2015-02-01

340

Metallicity of M dwarfs. III. Planet-metallicity and planet-stellar mass correlations of the HARPS GTO M dwarf sample  

NASA Astrophysics Data System (ADS)

Aims: The aim of this work is the study of the planet-metallicity and the planet-stellar mass correlations for M dwarfs from the HARPS GTO M dwarf subsample. Methods: We use a new method that takes advantage of the HARPS high-resolution spectra to increase the precision of metallicity, using previous photometric calibrations of [Fe/H] and effective temperature as starting values. Results: In this work we use our new calibration (rms = 0.08 dex) to study the planet-metallicity relation of our sample. The well-known correlation for giant planet FGKM hosts with metallicity is present. Regarding Neptunians and smaller hosts no correlation is found but there is a hint that an anti-correlation with [Fe/H] may exist. We combined our sample with the California Planet Survey late-K and M-type dwarf sample to increase our statistics but found no new trends. We fitted a power law to the frequency histogram of the Jovian hosts for our sample and for the combined sample, fp = C10? [Fe/H] , using two different approaches: a direct bin fitting and a Bayesian fitting procedure. We obtained a value for C between 0.02 and 0.04 and for ? between 1.26 and 2.94. Regarding stellar mass, an hypothetical correlation with planets was discovered, but was found to be the result of a detection bias. Based on observations made with the HARPS instrument on the ESO 3.6-m telescope at La Silla Observatory under programme ID 072.C-0488.Tables 2, 8, and Appendix A are available in electronic form at http://www.aanda.org

Neves, V.; Bonfils, X.; Santos, N. C.; Delfosse, X.; Forveille, T.; Allard, F.; Udry, S.

2013-03-01

341

arXiv:0908.0297v1[astro-ph.EP]3Aug2009 WASP-16b: A new Jupiter-like planet transiting a southern solar  

E-print Network

Avenue, Pasadena, CA 91125, USA 13Isaac Newton Group of Telescopes, Apartado de Correos 321, E-38700 spectroscopic data leads to a planet with Rp = 1.008 ± 0.071 RJup and Mp = 0.855±0.059 MJup, orbiting a host

Norton, Andrew J.

342

A Transiting Planet of a Sun-like Star  

E-print Network

A planet transits an 11th magnitude, G1V star in the constellation Corona Borealis. We designate the planet XO-1b, and the star, XO-1, also known as GSC 02041-01657. XO-1 lacks a trigonometric distance; we estimate it to be 200+-20 pc. Of the ten stars currently known to host extrasolar transiting planets, the star XO-1 is the most similar to the Sun in its physical characteristics: its radius is 1.0+-0.08 R_Sun, its mass is 1.0+-0.03 M_Sun, V sini < 3 km/s, and its metallicity [Fe/H] is 0.015+-0.04. The orbital period of the planet XO-1b is 3.941534+-0.000027 days, one of the longer ones known. The planetary mass is 0.90+-0.07 M_Jupiter, which is marginally larger than that of other transiting planets with periods between 3 and 4 days. Both the planetary radius and the inclination are functions of the spectroscopically determined stellar radius. If the stellar radius is 1.0+-0.08 R_Sun, then the planetary radius is 1.30+-0.11 R_Jupiter and the inclination of the orbit is 87.7+-1.2 degrees. We have demonstrated a productive international collaboration between professional and amateur astronomers that was important to distinguishing this planet from many other similar candidates.

P. R. McCullough; J. E. Stys; Jeff A. Valenti; C. M. Johns-Krull; K. A. Janes; J. N. Heasley; B. A. Bye; C. Dodd; S. W. Fleming; A. Pinnick; R. Bissinger; B. L. Gary; P. J. Howell; T. Vanmunster

2006-05-17

343

Late-stage accretion and habitability of terrestrial planets  

NASA Astrophysics Data System (ADS)

The final stage in the formation of terrestrial planets consists of the accumulation of ~1000 km "planetary embryos" and ~1 km planetesimals via collisional accretion., under the mutual gravity of other solid bodies and the gas giant planets (if any). Water is delivered to planets via collisions with volatile-rich bodies that condensed past the snow line, beyond about 2.5 AU. We present results of a large number of relatively low-resolution simulations, designed to assess the predictability of systems of terrestrial planets as a function of "observables" such as the orbit of gas giant planets. These show that a variety of terrestrial planets can form, from small, dry, Mars-like worlds to planets with similar properties to Earth, to >3 Earth mass "water worlds" with >=30 times as much water as the Earth. The terrestrial planets are largely shaped by the influence of the giant planets and the surface density of material. We have uncovered trends between the terrestrial planets and (i) the mass, (ii) the orbital distance and (iii) the orbital eccentricity of a giant planet, (iv) the surface density of the disk, and (v) the disk's density profile. Five simulations with 1000-2000 particles reveal new aspects of the accretion process Water is delivered to the terrestrial planets as a few large planetesimals in a "hit or miss" process, and as billions of planetesimals in a robust way. The water delivery process is therefore more robust than previously thought, implying that the range of water contents of extra-solar Earths is less stochastic than indicated in previous studies; most planets accrete water- rich bodies. We simulate terrestrial accretion in the presence of close-in giant planets (e.g., "hot jupiters"), assuming these form and migrate quickly. Potentially habitable planets can form in these systems, but are likely to be iron-poor. Asteroid belts may exist between the terrestrial planets and hot jupiters in these systems. We have also tested the accretion process in four known extra- solar planetary systems. In 55 Cancri, terrestrial planets form relatively easily, and may have orbits in the habitable zone and significant water contents.

Raymond, Sean Neylon

344

Arsine in Saturn and Jupiter  

NASA Technical Reports Server (NTRS)

New spectra of Saturn and Jupiter are reported that show a prominent, heretofore unidentified absorption near 2126/cm. The observation is interpreted as unambiguous evidence for the presence of arsine, AsH3. The abundance of AsH3 appears to be almost a factor of two higher in Saturn than in Jupiter. The observed enrichments are consistent with the core instability model for the formation of giant planets. Models of arsenic chemistry that predict strong depletions of AsH3 at temperatures below 370 K are not consistent with the observations, suggesting that vertical convection or perhaps some other mechanism inhibits depletion. Arsenic is the first new element identified in a planetary atmosphere since germanium was found in Jupiter a decade ago.

Noll, Keith S.; Geballe, T. R.; Knacke, R. F.

1989-01-01

345

Infrared Radiation from Hot Jupiters  

E-print Network

Recent Spitzer infrared (IR) observations of two transiting hot Jupiters during their secondary eclipses have provided the first direct detection of planets orbiting other stars (Charbonneau et al. 2005; Deming et al. 2005). We here elaborate on some aspects of our detection of HD209458b at 24 microns, and we compare to the detection of TrES-1 by Charbonneau et al. Spitzer will eventually determine the IR spectral energy distribution of these and similar hot Jupiters, opening the new field of comparative exoplanetology. For now, we have only three Spitzer data points, augmented by upper limits from the ground. We here interpret the available measurements from a purely observational perspective, and we point out that a blackbody spectrum having T=1100K can account for all current IR measurements, within the errors. This will surely not remain true for long, since ongoing Spitzer observations will be very sensitive to the IR characteristics of hot Jupiters.

Drake Deming; L. Jeremy Richardson; Sara Seager; Joseph Harrington

2005-11-10

346

Jupiter's Ring Halo  

NASA Technical Reports Server (NTRS)

A mosaic of four images taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 8, 1996, at a resolution of approximately 46 kilometers (km) per picture element (pixel) along the rings; however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow peering back toward the Sun; the ring was approximately 2,300,000 kilometers (km) away. The arc on the far right of the image is produced by sunlight scattered by small particles comprising Jupiter's upper atmospheric haze. The ring also efficiently scatters light, indicating that much of its brightness is due to particles that are microns or less in diameter. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age.

Jupiter's ring system is composed of three parts -- a flat main ring, a lenticular halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The near and far arms of Jupiter's main ring extend horizontally across the mosaic, joining together at the ring's ansa, on the far left side of the figure. The near arm of the ring appears to be abruptly truncated close to the planet, at the point where it passes into Jupiter's shadow.

A faint mist of particles can be seen above and below the main rings; this vertically extended, toroidal 'halo' is unusual in planetary rings, and is probably caused by electromagnetic forces which can push small grains out of the ring plane. Halo material is present across this entire image, implying that it reaches more than 27,000 km above the ring plane. Because of shadowing, the halo is not visible close to Jupiter in the lower right part of the mosaic. In order to accentuate faint features in the image, different brightnesses are shown through color, with the brightest being white or yellow and the faintest purple.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at: http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at: http:/ /www.jpl.nasa.gov/galileo/sepo.

1997-01-01

347

The Chemistry of the Planets.  

ERIC Educational Resources Information Center

Introduces knowledge of planetary chemistry for possible use in teaching. Discusses the chemical composition of the planets; the atmosphere and clouds of Venus, Jupiter and its moons, and Titan. Includes diagrams of the greenhouse effects in the solar system, elemental abundances, and the chemical composition of Jupiter. (RT)

Blake, Peter

1988-01-01

348

The formation of Uranus and Neptune in the Jupiter-Saturn region of the Solar System.  

PubMed

Planets are believed to have formed through the accumulation of a large number of small bodies. In the case of the gas-giant planets Jupiter and Saturn, they accreted a significant amount of gas directly from the protosolar nebula after accumulating solid cores of about 5-15 Earth masses. Such models, however, have been unable to produce the smaller ice giants Uranus and Neptune at their present locations, because in that region of the Solar System the small planetary bodies will have been more widely spaced, and less tightly bound gravitationally to the Sun. When applied to the current Jupiter-Saturn zone, a recent theory predicts that, in addition to the solid cores of Jupiter and Saturn, two or three other solid bodies of comparable mass are likely to have formed. Here we report the results of model calculations that demonstrate that such cores will have been gravitationally scattered outwards as Jupiter, and perhaps Saturn, accreted nebular gas. The orbits of these cores then evolve into orbits that resemble those of Uranus and Neptune, as a result of gravitational interactions with the small bodies in the outer disk of the protosolar nebula. PMID:10604469

Thommes, E W; Duncan, M J; Levison, H F

1999-12-01

349

DISCOVERY OF A PROBABLE 4-5 JUPITER-MASS EXOPLANET TO HD 95086 BY DIRECT IMAGING  

SciTech Connect

Direct imaging has only begun to inventory the population of gas giant planets on wide orbits around young stars in the solar neighborhood. Following this approach, we carried out a deep imaging survey in the near-infrared using VLT/NaCo to search for substellar companions. Here we report the discovery of a probable companion orbiting the young (10-17 Myr), dusty, early-type (A8) star HD 95086 at 56 AU in L' (3.8 {mu}m) images. This discovery is based on observations with more than a year time lapse. Our first epoch clearly revealed the source at {approx_equal} 10{sigma}, while our second epoch lacks good observing conditions, yielding a {approx_equal} 3{sigma} detection. Various tests were thus made to rule out possible artifacts. This recovery is consistent with the signal at the first epoch but requires cleaner confirmation. Nevertheless, our astrometric precision suggests that the companion is comoving with the star with a 3{sigma} confidence level. The planetary nature of the source is reinforced by a non-detection in the Ks-band (2.18 {mu}m) images according to its possible extremely red Ks-L' color. Conversely, background contamination is rejected with good confidence level. The luminosity yields a predicted mass of about 4-5 M{sub Jup} (at 10-17 Myr) using ''hot-start'' evolutionary models, making HD 95086 b the exoplanet with the lowest mass ever imaged around a star.

Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Delorme, P. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble F-38041 (France); Boccaletti, A. [LESIA, Observatoire de Paris, CNRS, University Pierre et Marie Curie Paris 6 and University Denis Diderot Paris 7, 5 place Jules Janssen, F-92195 Meudon (France); Quanz, S. P. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich (Switzerland); Bonnefoy, M.; Klahr, H.; Mordasini, C. [Max Planck Institute for Astronomy, Koenigsthul 17, D-69117 Heidelberg (Germany); Girard, J. H.; Dumas, C. [European Southern Observatory, Casilla 19001, Santiago 19 (Chile); Desidera, S.; Bonavita, M., E-mail: julien.rameau@obs.ujf-grenoble.fr [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

2013-08-01

350

Direct Imaging of Warm Extrasolar Planets  

SciTech Connect

One of the most exciting scientific discoveries in the last decade of the twentieth century was the first detection of planets orbiting a star other than our own. By now more than 130 extrasolar planets have been discovered indirectly, by observing the gravitational effects of the planet on the radial velocity of its parent star. This technique has fundamental limitations: it is most sensitive to planets close to their star, and it determines only a planet's orbital period and a lower limit on the planet's mass. As a result, all the planetary systems found so far are very different from our own--they have giant Jupiter-sized planets orbiting close to their star, where the terrestrial planets are found in our solar system. Such systems have overturned the conventional paradigm of planet formation, but have no room in them for habitable Earth-like planets. A powerful complement to radial velocity detections of extrasolar planets will be direct imaging--seeing photons from the planet itself. Such a detection would allow photometric measurements to determine the temperature and radius of a planet. Also, direct detection is most sensitive to planets in wide orbits, and hence more capable of seeing solar systems resembling our own, since a giant planet in a wide orbit does not preclude the presence of an Earth-like planet closer to the star. Direct detection, however, is extremely challenging. Jupiter is roughly a billion times fainter than our sun. Two techniques allowed us to overcome this formidable contrast and attempt to see giant planets directly. The first is adaptive optics (AO) which allows giant earth-based telescopes, such as the 10 meter W.M. Keck telescope, to partially overcome the blurring effects of atmospheric turbulence. The second is looking for young planets: by searching in the infrared for companions to young stars, we can see thermal emission from planets that are still warm with the heat of their formation. Together with a UCLA team that leads the field of young-star identification, we carried out a systematic near-infrared search for young planetary companions to {approx}200 young stars. We also carried out targeted high-sensitivity observations of selected stars surrounded by circumstellar dust rings. We developed advanced image processing techniques to allow detection of even fainter sources buried in the noisy halo of scattered starlight. Even with these techniques, around most of our targets our search was only sensitive to planets in orbits significantly wider than our solar system. With some carefully selected targets--very young dusty stars in the solar neighborhood--we reach sensitivities sufficient to see solar systems like our own. Although we discovered no unambiguous planets, we can significantly constrain the frequency of such planets in wide (>50 AU) orbits, which helps determine which models of planet formation remain plausible. Successful modeling of our observations has led us to the design of a next-generation AO system that will truly be capable of exploring solar systems resembling our own.

Macintosh, B

2005-04-11

351

Friends of hot Jupiters II: No correspondence between hot Jupiter spin-orbit misalignment and the incidence of directly imaged stellar companions  

NASA Astrophysics Data System (ADS)

A large fraction of nearby solar-like stars are found in multi-star systems. We currently know very little about the effects that a stellar companion might have on planet formation and evolution in these systems. It has been suggested that such companions might hinder planet formation by dynamically exciting or truncating the protoplanetary disk, or by causing the planets to migrate from their formation locations. We present results from a survey focused on a class of short-period gas giant planets known as hot Jupiters, which must have formed beyond their stars' ice lines and then migrated inwards to their present locations. Many of these planets have orbits that are misaligned with respect to their star's spin axis, and it has been suggested that the most likely explanation for this misalignment is dynamical evolution due to an as-yet undetected outer companion. We surveyed a sample of 50 transiting hot Jupiters with NIRC2 AO K-band imaging and found a total of 20 stellar companions around 18 stars. We obtained a second epoch of data for all candidate companions and found that they were all bound companions to the FGK stars hosting the transiting hot Jupiters. This AO survey is part of a larger Keck-based campaign including both long term radial velocity monitoring with HIRES and high resolution infrared spectroscopy with NIRSPEC, which allows us to detect companions over a broad range of mass ratios and orbital semi-major axes. Our AO survey is sensitive to companions with approximate separations between 10 and 1000 AU. In this regime, we find that companion stars are more common around close-in transiting gas giant planetary hosts than field stars. However, we find no connection between misaligned planet hosts and stellar multiplicity.

Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Crepp, Justin R.; Bechter, Eric B.; Batygin, Konstantin; Howard, Andrew W.; Johnson, John A.; Morton, Timothy D.; Muirhead, Philip Steven

2015-01-01

352

Voyager 1 Jupiter Southern Hemisphere Movie  

NASA Technical Reports Server (NTRS)

This movie shows a portion of Jupiter in the southern hemisphere over 17Jupiter days. Above the white belt, notice the series of atmospheric vortices headed west. Even these early approach frames show wild dynamics in the roiling environment south of the white belt. Notice the small tumbling white cloud near the center.

As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 17 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Blue filter around Feb. 1, 1979. The spacecraft was about 37 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

353

HD 285507b: An Eccentric Hot Jupiter in the Hyades Open Cluster  

NASA Astrophysics Data System (ADS)

We report the discovery of the first hot Jupiter in the Hyades open cluster. HD 285507b orbits a V = 10.47 K4.5V dwarf (M * = 0.734 M ? R * = 0.656 R ?) in a slightly eccentric (e=0.086^{+0.018}_{-0.019}) orbit with a period of 6.0881^{+0.0019}_{-0.0018} days. The induced stellar radial velocity corresponds to a minimum companion mass of M Psin i = 0.917 ± 0.033 M Jup. Line bisector spans and stellar activity measures show no correlation with orbital phase, and the radial velocity amplitude is independent of wavelength, supporting the conclusion that the variations are caused by a planetary companion. Follow-up photometry indicates with high confidence that the planet does not transit. HD 285507b joins a small but growing list of planets in open clusters, and its existence lends support to a planet formation scenario in which a high stellar space density does not inhibit giant planet formation and migration. We calculate the circularization timescale for HD 285507b to be larger than the age of the Hyades, which may indicate that this planet's non-zero eccentricity is the result of migration via interactions with a third body. We also demonstrate a significant difference between the eccentricity distributions of hot Jupiters that have had time to tidally circularize and those that have not, which we interpret as evidence against Type II migration in the final stages of hot Jupiter formation. Finally, the dependence of the circularization timescale on the planetary tidal quality factor, Q P, allows us to constrain the average value for hot Jupiters to be log {Q_P} = 6.14^{+0.41}_{-0.25}.

Quinn, Samuel N.; White, Russel J.; Latham, David W.; Buchhave, Lars A.; Torres, Guillermo; Stefanik, Robert P.; Berlind, Perry; Bieryla, Allyson; Calkins, Michael C.; Esquerdo, Gilbert A.; F?rész, Gabor; Geary, John C.; Szentgyorgyi, Andrew H.

2014-05-01

354

Formation of Planets Around the Sun and Other Stars.  

SciTech Connect

Formation of Planets around the Sun and other stars. The quest to understand the formation of planets and planetary systems has entered an era of renaissance. Driven by observational discoveries in solar system exploration, protostellar disks, and extra solar planets, we have established a rich data bank which contains not only relic clues around mature stars, including the Sun, but also direct image of ongoing processes around young stars. For the first time in this scientific endeavor, we have adequate information to construct quantitative models to account for the ubiquity of planets and diversity of planetary systems. Some of the most intriguing theoretical questions facing us today include: a) how did the planets in the solar system form with their present-day mass, composition, and orbital elements, b) is planet formation a deterministic or chaotic process, and c) what are the observable signatures of planet formation and evolution around nearby young and mature stars? I will present a comprehensive scenario which suggests a) gas giant planets formed through coagulation of planetsimals and gas accretion onto earth-like cores; b) the final assemblage of the terrestrial planets in the solar system occurred through the propagation of Jupiter's secular resonance 4-30 Myrs after the emergence of the gas giant; and c) although they are yet to be discovered, Earth-like planets are expected to be common around nearby stars.

Professor Doug Lin

2005-11-14

355

Hubble Images Reveal Jupiter's Auroras  

NASA Technical Reports Server (NTRS)

These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.

The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.

The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.

The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.

The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

1996-01-01

356

Recent Insights into the Intrinsic Magnetic Fields of Jupiter and Saturn  

NASA Astrophysics Data System (ADS)

The gas giant planets, Jupiter and Saturn, not only played important roles in the evolution of our solar system but also are representative of many exoplanets of this type. Many similarities are shared by these two planets. The major compositions of both planets are hydrogen and helium. In the atmosphere of both planets, helium mass ratios are found to be smaller than proto-solar value; most of the measured heavy elements, other than neon, are found to be enhanced compared to the proto-solar value. Both planets emit as much as twice the power they receive from the Sun respectively. Whether these two planets possess a central core and what is the mass and size of the core is still under debate given all the observational data. Both Jupiter and Saturn possess global-scale magnetic fields. Dynamo actions in the convecting metallic hydrogen layers are believed to be responsible for these observed magnetic fields. Measuring and characterizing magnetic fields can enhance our understandings of the interior structures and dynamics of the host planets. We will present our characterization of the intrinsic magnetic fields of both planets in terms of field strength, non-axisymmetry, secular variation, high-degree moments based on in-situ magnetic field measurements made by space missions (Pioneer 11, Voyager 1 and Galileo for Jupiter and Pioneer 11, Voyager 1 & 2 and Cassini for Saturn), traceable "ground" features - Auroral footprints of Io and Enceladus will also be considered. For Saturn, we find not only no evidence for any departure from axisymmetry but also that the magnetic flux inside Saturn is strongly concentrated near the spin-poles, in contrast to the well-defined polar field minima observed at the surface of the Earth's core and in geodynamo models. For Jupiter, the departure from axisymmetry is evident but currently available measurements cannot discern whether the magnetic fields at the polar regions of the dynamo surface are at maxima or minima. However, auroral features indeed indicate strong north-south asymmetries in Jupiter's surface magnetic field. Solid-body rotation of the dynamo region can be monitored by the tracing the non-axisymmetric magnetic fields and radio emissions of Jupiter. A similar procedure has not yielded unambiguous results for Saturn due to the extreme axisymmetry of the magnetic field. Large-scale circulation (e.g. differential rotation) at the surface of the dynamo region of Jupiter will produce magnetic signals expressed as secular variations. We seek to put upper-bounds on the velocity of large-scale circulation at the surface of the dynamo region of Jupiter by comparing forward modeling and magnetic field measurements made in the inner Jovian magnetosphere from different epochs. Helium re-distribution likely has occurred inside both Jupiter and Saturn, as a result of the crossing of the adiabats and hydrogen-helium immiscibility curve. The possible effects on dynamo action will also be discussed.

Cao, Hao; Russell, Christopher; Dougherty, Michele

2014-05-01

357

Atmospheric mass loss during planet formation: The importance of planetesimal impacts  

NASA Astrophysics Data System (ADS)

Quantifying the atmospheric mass loss during planet formation is crucial for understanding the origin and evolution of planetary atmospheres. We examine the contributions to atmospheric loss from both giant impacts and planetesimal accretion. Giant impacts cause global motion of the ground. Using analytic self-similar solutions and full numerical integrations we find (for isothermal atmospheres with adiabatic index ?=5/3) that the local atmospheric mass loss fraction for ground velocities vg?0.25vesc is given by ?loss=(1.71, where vesc is the escape velocity from the target. Yet, the global atmospheric mass loss is a weaker function of the impactor velocity vImp and mass mImp and given by Xloss?0.4x+1.4x2-0.8x3 (isothermal atmosphere) and Xloss?0.4x+1.8x2-1.2x3 (adiabatic atmosphere), where x=(vImpm/vescM). Atmospheric mass loss due to planetesimal impacts proceeds in two different regimes: (1) large enough impactors m??{2}?0( (25 km for the current Earth), are able to eject all the atmosphere above the tangent plane of the impact site, which is h/2R of the whole atmosphere, where h, R and ?0 are the atmospheric scale height, radius of the target, and its atmospheric density at the ground. (2) Smaller impactors, but above m>4??0h3 (1 km for the current Earth) are only able to eject a fraction of the atmospheric mass above the tangent plane. We find that the most efficient impactors (per unit impactor mass) for atmospheric loss are planetesimals just above that lower limit (2 km for the current Earth). For impactor flux size distributions parametrized by a single power law, N(>r)?r, with differential power law index q, we find that for 1mass loss proceeds in regime (1) whereas for q>3 the mass loss is dominated by regime (2). Impactors with m?4??0h3 are not able to eject any atmosphere. Despite being bombarded by the same planetesimal population, we find that the current differences in Earth's and Venus' atmospheric masses can be explained by modest differences in their initial atmospheric masses and that the current atmosphere of the Earth could have resulted from an equilibrium between atmospheric erosion and volatile delivery to the atmosphere from planetesimal impacts. We conclude that planetesimal impacts are likely to have played a major role in atmospheric mass loss over the formation history of the terrestrial planets.

Schlichting, Hilke E.; Sari, Re'em; Yalinewich, Almog

2015-02-01

358

Value of Hipparcos Catalogue shown by planet assessments  

NASA Astrophysics Data System (ADS)

The first detailed findings from Hipparcos, recently published in Astronomy and Astrophysics Letters, confirm the existence of planets around other stars. Hipparcos astronomers plucked out their data on three stars suspected of possessing attendant planets. Their distances, measured far more accurately than ever before, enables the astronomers to rule out, in two cases, the possibility that the supposed planets might be small stars. The discovery of alien planets in the first astronomical step towards fashioning a proper science out of the speculations about life beyond the solar system. Hipparcos makes a decisive contribution by setting an upper limit to their masses. Astronomers at the Geneva Observatory caused a sensation last year when they reported slight motions in the star 51 Pegasi, due to a massive planet orbiting around it. With a ground-based telescope they detected small shifts in the wavelength of light as 51 Pegasi moved slowly under the influence of its invisible companion. This year, astronomers at San Francisco State University confirmed the discovery and have subsequently reported two similar cases, in the stars 47 Ursae Majoris and 70 Virginis. Uncertainties about the orientation of the planets' orbits and the distances of the stars left a wide margin of doubt about the masses of the candidate planets. Accurate rangefinding by Hipparcos puts the star 47 Ursae Majoris at a distance of 46 light-years. Calculations then set an upper limit on the mass of the companion at 7 to 22 times the mass of Jupiter, the Sun's largest planet. The Sun itself is a thousand times more massive that Jupiter, and theorists believe that the smallest true star would have a mass of 80 Jupiters. Below that mass, the object cannot burn hydrogen in the nuclear fashion, which is the most characteristic source of energy for stars. In the range between 17 and 80 Jupiter masses an object is called a brown dwarf. It can in theory derive a little energy by burning heavy hydrogen, or deuterium. Even the "worst-case" mass quoted here for the companion of 47 Ursae Majoris, 22 Jupiter masses, is only a maximum, not a measurement. So the companion is almost certainly a true planet with less than 17 times the mass of Jupiter. For the star 70 Virginis, the distance newly established by Hipparcos is 59 light-years. Even on the least favourable assumptions about its orbit, the companion cannot have more than 65 Jupiter masses. It could be brown dwarf rather than a planet, but not a true star. Much more ambiguous is the result for 51 Pegasi. Its distance is 50 light-years and theoretically the companion could have more than 500 Jupiter masses, or half the mass of the Sun. This is a peculiar case anyway, because the companion is very close to 51 Pegasi. Small planets of the size of the Earth might be more promising as abodes of life than the large planets detectable by present astronomical methods. Space scientists are now reviewing methods of detecting the presence of life on alien planets by detecting the infrared signature of ozone in a planet's atmosphere. Ozone is a by-product of oxygen gas, which in turn is supposed to be generated only by life similar to that on the Earth. Meanwhile the detection of planets of whatever size is a tour de force for astronomers, and by analogy with the Solar System one may suppose that large planets are often likely to be accompanied by smaller ones. "Hipparcos was not conceived to look for planets," comments Michael Perryman, ESA's project scientist for Hipparcos, "and this example of assistance to our fellow-astronomers involves a very small sample of our measurements. But it is a timely result when we are considering planet-hunting missions for the 21st Century. The possibilities include a super-Hipparcos that could detect directly the wobbles in nearby stars due to the presence of planets." Hipparcos Catalogue ready for use The result from Hipparcos on alien planets coincides with the completion of the Hipparcos Catalogue and the distribution of the data to collaborating scie

1996-08-01

359

Embryo impacts and gas giant mergers II: Diversity of Hot Jupiters' internal structure  

E-print Network

We consider the origin of compact, short-period, Jupiter-mass planets. We propose that their diverse structure is caused by giant impacts of embryos and super-Earths or mergers with other gas giants during the formation and evolution of these hot Jupiters. Through a series of numerical simulations, we show that typical head-on collisions generally lead to total coalescence of impinging gas giants. Although extremely energetic collisions can disintegrate the envelope of gas giants, these events seldom occur. During oblique and moderately energetic collisions, the merger products retain higher fraction of the colliders' cores than their envelopes. They can also deposit considerable amount of spin angular momentum to the gas giants and desynchronize their spins from their orbital mean motion. We find that the oblateness of gas giants can be used to infer the impact history. Subsequent dissipation of stellar tide inside the planets' envelope can lead to runaway inflation and potentially a substantial loss of gas ...

Liu, Shang-Fei; Lin, D N C; Li, Shu-Lin

2014-01-01

360

Seven transiting hot Jupiters from WASP-South, Euler and TRAPPIST: WASP-47b, WASP-55b, WASP-61b, WASP-62b, WASP-63b, WASP-66b and WASP-67b  

NASA Astrophysics Data System (ADS)

We present seven new transiting hot Jupiters from the WASP-South survey. The planets are all typical hot Jupiters orbiting stars from F4 to K0 with magnitudes of V = 10.3-12.5. The orbital periods are all in the range of 3.9-4.6 d, the planetary masses range from 0.4 to 2.3 MJup and the radii from 1.1 to 1.4 RJup. In line with known hot Jupiters, the planetary densities range from Jupiter-like to inflated (? = 0.13-1.07?Jup). We use the increasing numbers of known hot Jupiters to investigate the distribution of their orbital periods and the 3-4 d 'pile-up'.

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

2012-10-01

361

Jupiter Magnetospheric Orbiter and Trojan Asteroid Explorer in EJSM (Europa Jupiter System Mission)  

NASA Astrophysics Data System (ADS)

Europa Jupiter System Mission (EJSM) is an international mission to explore and Jupiter, its satellites and magnetospheric environment in 2020s. EJSM consists of (1) The Jupiter Europa Orbiter (JEO) by NASA, (2) the Jupiter Ganymede Orbiter (JGO) by ESA, and (3) the Jupiter Magnetospheric Orbiter (JMO) studied by JAXA (Japan Aerospace Exploration Agency). In February 2009, NASA and ESA decided to continue the study of EJSM as a candidate of the outer solar system mission. JMO will have magnetometers, low-energy plasma spectrometers, medium energy particle detectors, energetic particle detectors, electric field / plasma wave instruments, an ENA imager, an EUV spectrometer, and a dust detector. Collaborating with plasma instruments on board JEO and JGO, JMO will investigate the fast and huge rotating magnetosphere to clarify the energy procurement from Jovian rotation to the magnetosphere, to clarify the interaction between the solar wind the magnetosphere. Especially when JEO and JGO are orbiting around Europa and Ganymede, respectively, JMO will measure the outside condition in the Jovian magnetosphere. JMO will clarify the characteristics of the strongest accelerator in the solar system with the investigation of the role of Io as a source of heavy ions in the magnetosphere. JAXA started a study of a solar power sail for deep space explorations. Together with a solar sail (photon propulsion), it will have very efficient ion engines where electric power is produced solar panels within the sail. JAXA has already experienced ion engine in the successful Hayabusa mission, which was launched in 2003 and is still in operation in 2010. For the purpose of testing solar power sail technology, an engineering mission IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) will be launched in 2010 together with Venus Climate Orbiter PLANET-C. The shape of the IKAROS' membrane is square, with a diagonal distance of 20m. It is made of polyimide film only 0.0075mm thick. Currently we are studying a mission to Jupiter and one (or two) of Trojan asteroids using a large (100m-scale) solar power sail that can transfer large payload mass as far as Jupiter. Trojan asteroids are primitive bodies with information of the early solar system as well as raw solid materials of Jovian system. According to the mission plan, as the main spacecraft flies by Jupiter, it will deploy a JMO spinner around Jupiter. Proposed instruments on board Trojan spacecraft are cameras, IR spectrometers, XRS, a laser altimeter, and a surface vehicle (if rendezvous with the target is possible). An instrument for measuring cosmic background is also proposed. Currently JEO and JGO will be launched in 2020 and the Trojan spacecraft with JMO shall be launched at the same window. The mission (Trojan-JMO) will take 6 years to Jupiter and 5 years more to a Trojan asteroid around L4. The mission study team also includes J. Kawaguchi, Y. Kawakatsu, and M. Morimoto of JAXA.

Sasaki, Sho; Fujimoto, Masaki; Takashima, Takeshi; Yano, Hajime; Kasaba, Yasumasa; Takahashi, Yukihiro; Kimura, Jun; Tsuda, Yuichi; Funase, Ryu; Mori, Osamu

2010-05-01

362

Terrestrial Planet Growth in Circumbinary Disks  

NASA Technical Reports Server (NTRS)

We examine the accuulation of terrestrial from circumbinary disks surrounding pairs of stars with masses of either 0.5 solar masses each or 0.8 and 0.2 solar masses and orbital separations of 0.05 AU to 0.4 AU by performing numerical simulations of the late stages of planetary growth. Initial disks contain about 2.6 Earth masses of lunar to Mars-sized bodies orbiting within 2 AU of the center of mass of the system, plus giant planets with masses and orbits analogous to those of Jupiter and Saturn. We also performed simulations using analogous disks orbiting single 1 solar mass stars. The dynamics of planetary growth is quite chaotic because the gravitational perturbations resulting from close approaches greatly amplify differences in orbits. Thus, several simulations of each configuration were run with very slightly different initial conditions to enable us to distinguish systematic effects resulting from differences in the binary orbit (or differences of the initial orbits of the bodies within the disk) from pseudo-random variability in outcomes resulting from chaos. Most runs simulated 200 million years of evolution. At least one terrestrial planet remained at the end of each run; one simulation produced 6 terrestrial planets in a configuration that appears to be quite stable. The systems that formed around stars with binary apastron separations of less than 0.2 AU contained on average slightly more planets than those that formed around single stars, with the outermost planet typically orbiting at a greater distance from the system barycenter. Greater stellar separations tended to result in fewer planets, with the inner planet orbiting farther from the stars. More eccentric binaries have a more pronounced effect for the same apastron distance. The statistical distribution of final systems is not sensitive to moderate differences in the initial eccentricities of the bodies in the disk.

Lissauer, J. J.; Quintana, E. V.

2006-01-01

363

Ganymede and Jupiter  

NASA Technical Reports Server (NTRS)

The solar system's largest moon, Ganymede, is captured here alongside the planet Jupiter in a color picture taken by NASA's Cassini spacecraft on Dec. 3, 2000.

Ganymede is larger than the planets Mercury and Pluto and Saturn's largest moon, Titan. Both Ganymede and Titan have greater surface area than the entire Eurasian continent on our planet. Cassini was 26.5 million kilometers (16.5 million miles) from Ganymede when this image was taken. The smallest visible features are about 160 kilometers (about 100 miles) across.

The bright area near the south (bottom) of Ganymede is Osiris, a large, relatively new crater surrounded by bright icy material ejected by the impact, which created it. Elsewhere, Ganymede displays dark terrains that NASA's Voyager and Galileo spacecraft have shown to be old and heavily cratered. The brighter terrains are younger and laced by grooves. Various kinds of grooved terrains have been seen on many icy moons in the solar system. These are believed to be the surface expressions of warm, pristine, water-rich materials that moved to the surface and froze.

Ganymede has proven to be a fascinating world, the only moon known to have a magnetosphere, or magnetic environment, produced by a convecting metal core. The interaction of Ganymede's and Jupiter's magnetospheres may produce dazzling variations in the auroral glows in Ganymede's tenuous atmosphere of oxygen.

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.

2000-01-01

364

The Juno Mission to Jupiter  

NASA Technical Reports Server (NTRS)

Origin: Determine O/H ratio (water abundance) and constrain core mass to decide among alternative theories of origin. Interior: Understand Jupiter's interior structure and dynamical properties by mapping its gravitational and magnetic fields Atmosphere: Map variations in atmospheric composition, temperature, cloud opacity and dynamics to depths greater than 100 bars at all latitudes. Magnetosphere: Characterize and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras.

Grammier, Richard S.

2006-01-01

365

Embryo impacts and gas giant mergers - II. Diversity of hot Jupiters' internal structure  

NASA Astrophysics Data System (ADS)

We consider the origin of compact, short-period, Jupiter-mass planets. We propose that their diverse structure is caused by giant impacts of embryos and super-Earths or mergers with other gas giants during the formation and evolution of these hot Jupiters. Through a series of numerical simulations, we show that typical head-on collisions generally lead to total coalescence of impinging gas giants. Although extremely energetic collisions can disintegrate the envelope of gas giants, these events seldom occur. During oblique and moderately energetic collisions, the merger products retain higher fraction of the colliders' cores than their envelopes. They can also deposit considerable amount of spin angular momentum to the gas giants and desynchronize their spins from their orbital mean motion. We find that the oblateness of gas giants can be used to infer the impact history. Subsequent dissipation of stellar tide inside the planets' envelope can lead to runaway inflation and potentially a substantial loss of gas through Roche lobe overflow. The impact of super-Earths on parabolic orbits can also enlarge gas giant planets' envelope and elevates their tidal dissipation rate over ˜100 Myr time scale. Since giant impacts occur stochastically with a range of impactor sizes and energies, their diverse outcomes may account for the dispersion in the mass-radius relationship of hot Jupiters.

Liu, Shang-Fei; Agnor, Craig B.; Lin, D. N. C.; Li, Shu-Lin

2015-01-01

366

Limits on Planets Around White Dwarf Stars  

E-print Network

We present limits on planetary companions to pulsating white dwarf stars. A subset of these stars exhibit extreme stability in the period and phase of some of their pulsation modes; a planet can be detected around such a star by searching for periodic variations in the arrival time of these pulsations. We present limits on companions greater than a few Jupiter masses around a sample of 15 white dwarf stars as part of an on-going survey. One star shows a variation in arrival time consistent with a 2 M_J planet in a 4.5 year orbit. We discuss other possible explanations for the observed signal and conclude that a planet is the most plausible explanation based on the data available.

F. Mullally; D. E. Winget; Steven Degennaro; Elizabeth Jeffery; S. E. Thompson; Dean Chandler

2008-01-20

367

Birth and fate of hot-Neptune planets  

E-print Network

This paper presents a consistent description of the formation and the subsequent evolution of gaseous planets, with special attention to short-period, low-mass hot-Neptune planets characteristic of $\\mu$ Ara-like systems. We show that core accretion including migration and disk evolution and subsequent evolution taking into account irradiation and evaporation provide a viable formation mechanism for this type of strongly irradiated light planets. At an orbital distance $a \\simeq$ 0.1 AU, this revised core accretion model leads to the formation of planets with total masses ranging from $\\sim$ 14 $\\mearth$ (0.044 $\\mjup$) to $\\sim$ 400 $\\mearth$ (1.25 $\\mjup$). The newly born planets have a dense core of $\\sim$ 6 $\\mearth$, independent of the total mass, and heavy element enrichments in the envelope, $M_{\\rm Z,env}/M_{\\rm env} $, varying from 10% to 80% from the largest to the smallest planets. We examine the dependence of the evolution of the born planet on the evaporation rate due to the incident XUV stellar flux. In order to reach a $\\mu$ Ara-like mass ($\\sim$ 14 $\\mearth$) after $\\sim $ 1 Gyr, the initial planet mass must range from 166 $\\mearth$ ($\\sim$ 0.52 $\\mjup$) to about 20 $\\mearth$, for evaporation rates varying by 2 orders of magnitude, corresponding to 90% to 20% mass loss during evolution. The presence of a core and heavy elements in the envelope affects appreciably the structure and the evolution of the planet and yields $\\sim 8%-9%$ difference in radius compared to coreless objects of solar composition for Saturn-mass planets. These combinations of evaporation rates and internal compositions translate into different detection probabilities, and thus different statistical distributions for hot-Neptunes and hot-Jupiters.

I. Baraffe; Y. Alibert; G. Chabrier; W. Benz

2005-12-05

368

Early Giant Planet Migration in the Solar System: Geochemical and Cosmochemical Implications for Terrestrial Planet Formation  

NASA Astrophysics Data System (ADS)

A new terrestrial planet formation model (Walsh et al., this meeting) 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). Walsh et al. show that the inward migration of Jupiter truncates the disk of planetesimals and embryos in the terrestrial planet region. Subsequent accretion in that region then forms a realistic system of terrestrial planets, in particular giving a low-mass Mars, which has been difficult to reproduce in simulations with a self-consistent set of initial conditions (see, eg. Raymond et al. 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. From a geochemical and cosmochemical point of view, this scenario differs significantly from the "standard model" in which essentially all of the material in the inner Solar System initially formed there. 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. This is important for understanding the chemical and isotopic diversity of the inner Solar System as inferred from studies of the terrestrial planets, asteroids, and meteorites, as well as for understanding the origin of Earth's water. We will discuss the geochemical and cosmochemical implications of this model in relation to available constraints, as well as to previous models of terrestrial planet formation. Masset & Snellgrove (2001), MNRAS 320, L55. Morbidelli & Crida (2007), Icarus 191, 158. Pierens & Nelson (2008), A&A 482, 333. Raymond et al. (2009), Icarus 203, 644.

O'Brien, David P.; Walsh, K. J.; Morbidelli, A.; Raymond, S. N.; Mandell, A. M.; Bond, J. C.

2010-10-01

369

Influence of Sudden Change of Solar Mass in the PN Stage on the Orbit of Earth-Like Planet  

NASA Astrophysics Data System (ADS)

Assuming that the terminated mass is confined within the range of 0.4551-0.5813 M ? when the sun is going to evolve into a white dwarf, the velocity of the sun projecting the shell in the PN stage is much greater than the revolving velocity of the earth-like planet, therefore, we think that the solar mass change is instantaneous.

Zhu, Yunfeng; Pan, Caijuan; Pan, Dasheng; Huang, Hongqiang; Chen, Zhi-Fu

2014-11-01

370

Limits to Transits of the Neptune-mass planet orbiting Gl 581  

E-print Network

We have monitored the Neptune-mass exoplanet-hosting M-dwarf Gl 581 with the 1m Swope Telescope at Las Campanas Observatory over two predicted transit epochs. A neutral density filter centered at 550nm was used during the first epoch, yielding 6.33 hours of continuous light curve coverage with an average photometric precision of 1.6 mmags and a cadence of 2.85 min. The second epoch was monitored in B-band over 5.85 hours, with an average photometric precision of 1.2 mmags and 4.28 min cadence. No transits are apparent on either night, indicating that the orbital inclination is less than 88.1 deg for all planets with radius larger than 0.38 R_Nep = 1.48 R_Earth. Because planets of most reasonable interior composition have radii larger than 1.55 R_Earth we place an inclination limit for the system of 88.1 deg. The corresponding minimum mass of Gl 581b remains 0.97 M_Nep = 16.6 M_Earth.

Mercedes Lopez-Morales; Nidia I. Morrell; R. Paul Butler; Sara Seager

2006-09-09

371

MEMS-based extreme adaptive optics for planet detection  

Microsoft Academic Search

The next major step in the study of extrasolar planets will be the direct detection, resolved from their parent star, of a significant sample of Jupiter-like extrasolar giant planets. Such detection will open up new parts of the extrasolar planet distribution and allow spectroscopic characterization of the planets themselves. Detecting Jovian planets at 5-50 AU scale orbiting nearby stars requires

B A Macintosh; J R Graham; B Oppenheimer; L Poyneer; A Sivaramakrishnan; J Veran

2005-01-01

372

MEMS-based extreme adaptive optics for planet detection  

Microsoft Academic Search

The next major step in the study of extrasolar planets will be the direct detection, resolved from their parent star, of a significant sample of Jupiter-like extrasolar giant planets. Such detection will open up new parts of the extrasolar planet distribution and allow spectroscopic characterization of the planets themselves. Detecting Jovian planets at 5-50 AU scale orbiting nearby stars requires

Bruce Macintosh; James Graham; Ben Oppenheimer; Lisa Poyneer; Anand Sivaramakrishnan; Jean-Pierre Veran

2006-01-01

373

Terrestrial Planet Formation in Extra-Solar Planetary Systems  

E-print Network

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding zones and the amount of radial mixing that occurs. The main factors that influence terrestrial planet formation are the mass and surface density profile of the disk, and the perturbations from giant planets and binary companions if they exist. Simple accretion models predicts that low-mass stars should form small, dry planets in their habitable zones. The migration of a giant planet through a disk of rocky bodies does not completely impede terrestrial planet growth. Rather, "hot Jupiter" systems are likely to also contain exterior, very water-rich Earth-like planets, and also "hot Earths", very close-in rocky planets. Roughly one third of the known systems of extra-solar (giant) planets could allow a terrestrial planet to form in the habitable zone.

Sean N. Raymond

2008-01-16

374

Jupiter's High-Altitude Clouds  

NASA Technical Reports Server (NTRS)

The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this incredibly detailed picture of Jupiter's high-altitude clouds starting at 06:00 Universal Time on February 28, 2007, when the spacecraft was only 2.3 million kilometers (1.4 million miles) from the solar system's largest planet. Features as small as 50 kilometers (30 miles) are visible. The image was taken through a narrow filter centered on a methane absorption band near 890 nanometers, a considerably redder wavelength than what the eye can see. Images taken through this filter preferentially pick out clouds that are relatively high in the sky of this gas giant planet because sunlight at the wavelengths transmitted by the filter is completely absorbed by the methane gas that permeates Jupiter's atmosphere before it can reach the lower clouds.

The image reveals a range of diverse features. The south pole is capped with a haze of small particles probably created by the precipitation of charged particles into the polar regions during auroral activity. Just north of the cap is a well-formed anticyclonic vortex with rising white thunderheads at its core. Slightly north of the vortex are the tendrils of some rather disorganized storms and more pinpoint-like thunderheads. The dark 'measles' that appear a bit farther north are actually cloud-free regions where light is completely absorbed by the methane gas and essentially disappears from view. The wind action considerably picks up in the equatorial regions where giant plumes are stretched into a long wave pattern. Proceeding north of the equator, cirrus-like clouds are shredded by winds reaching speeds of up to 400 miles per hour, and more pinpoint-like thunderheads are visible. Although some of the famous belt and zone structure of Jupiter's atmosphere is washed out when viewed at this wavelength, the relatively thin North Temperate Belt shows up quite nicely, as does a series of waves just north of the belt. The north polar region of Jupiter in this image has a mottled appearance, and the scene is not as dynamic as the equatorial and south polar regions.

The intricate structures revealed in this image are exciting, but they are only part of the story. The New Horizons instruments have taken images of Jupiter at approximately 260 different wavelengths, providing essentially a three-dimensional view of Jupiter's atmosphere, since images at different wavelengths probe different altitudes. New Horizons is providing a wealth of data on this fascinating planet during this last close-up view of Jupiter until the middle of the next decade.

2007-01-01

375

Juno: Launching to Jupiter - Duration: 4:44.  

NASA Video Gallery

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

376

Jupiter in Color, by Cassini  

NASA Technical Reports Server (NTRS)

This color image of Jupiter was taken by the camera onboard NASA's Cassini spacecraft when it was 81.3 million kilometers (50.5 million miles) from the planet. It is composed of images taken in the blue, green, and red regions of the spectrum and is therefore close to the true color of Jupiter that one would see through an Earth-based telescope.

The image is remarkably similar to images taken by NASA's Voyager 1 and 2 spacecraft more than 21 years ago, illustrating the stability of Jupiter's weather patterns. The parallel dark and bright bands and many other large-scale features are quasi-permanent structures that survive despite the intense small-scale activity ongoing in the atmosphere. The longevity of the large-scale features is an intrinsic property of the atmospheric flows on a gaseous planet such as Jupiter, with no solid surface. Smaller features, such as those in the dark bands north and south of the equator, are observed to form and disappear in a few days.

Everything visible on the planet is a cloud. Unlike Earth, where only water condenses to form clouds, Jupiter has several cloud-forming substances in its atmosphere. The updrafts and downdrafts bring different mixtures of these substances up from below, leading to clouds of different colors. The bluish features just north of the equator are regions of reduced cloud cover, similar to the place where the Galileo atmospheric probe entered in 1995. They are called 'hot spots' because the reduced cloud cover allows heat to escape from warmer, deeper levels in the atmosphere.

Jupiter's moon Europa is seen at the right, casting a shadow on the planet. Scientists believe Europa holds promise of a liquid ocean beneath its surface.

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

2000-01-01

377

Jupiter small satellite montage  

NASA Technical Reports Server (NTRS)

A montage of images of the small inner moons of Jupiter from the camera onboard NASA's Galileo spacecraft shows the best views obtained of these moons during Galileo's 11th orbit around the giant planet in November 1997. At that point, Galileo was completing its first two years in Jupiter orbit--known as the Galileo 'prime mission'--and was about to embark on a successful two-year extension, called the Galileo Europa Mission.

The top two images show the moon Thebe. Thebe rotates by approximately 50 degrees between the time these two images were taken, so that the same prominent impact crater is seen in both views; this crater, which has been given the provisional name Zethus, is near the point on Thebe that faces permanently away from Jupiter.

The next two images show the moon Amalthea; they were taken with the Sun directly behind the observer, an alignment that emphasizes patterns of intrinsically bright or dark surface material. The third image from the top is a view of Amalthea's leading side, the side of the moon that 'leads' as Amalthea moves in its orbit around Jupiter. This image looks 'noisy' because it was obtained serendipitously during an observation of the Jovian satellite Io (Amalthea and Io shared the same camera frame but the image was exposed for bright Io rather than for the much darker Amalthea). The fourth image from the top emphasizes prominent 'spots' of relatively bright material that are located near the point on Amalthea that faces permanently away from Jupiter. The bottom image is a view of the tiny moon Metis.

In all the images, north is approximately up, and the moons are shown in their correct relative sizes. The images are, from top to bottom: Thebe taken on November 7, 1997 at a range of 504,000 kilometers (about 313,000 miles); Thebe on November 7, 1997 at a range of 548,000 kilometers (about 340,000 miles); Amalthea on November 6, 1997 at a range of about 650,000 kilometers (about 404,000 miles); Amalthea on November 7, 1997 at a range of 475,000 kilometers (about 295,000 miles); Metis on November 7, 1997 at a range of 637,000 kilometers (about 396,000 miles).

2000-01-01

378

WEIGHING THE NON-TRANSITING HOT JUPITER {tau} Boo b  

SciTech Connect

We report the detection of the orbital velocity of non-transiting hot Jupiter {tau} Boo b. By employing high-resolution ground-based spectroscopy around 2.3 {mu}m during one half-night, we are able to detect carbon monoxide absorption lines produced in the planet atmosphere, which shift significantly in wavelength during the course of the observations due to the orbital motion of the planet. This detection of the planetary signal results in the determination of the orbital inclination as being i = 47{sup +7}{sub -6} deg and, furthermore, allows us to solve for the exact planetary mass, m{sub p} 5.6 {+-} 0.7 M{sub Jup}. This clearly confirms the planetary nature of the non-transiting companion to {tau} Boo.

Rodler, F.; Ribas, I. [Institut de Ciencies de l'Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5 parell, 2a planta, 08193, Bellaterra (Spain); Lopez-Morales, M., E-mail: rodler@ieec.uab.es [Visiting Investigator: Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road NW, Washington, DC 20015-1305 (United States)

2012-07-01

379

Hot-Jupiters and hot-Neptunes: a common origin?  

E-print Network

We compare evolutionary models for close-in exoplanets coupling irradiation and evaporation due respectively to the thermal and high energy flux of the parent star with observations of recently discovered new transiting planets. The models provide an overall good agreement with observations, although at the very limit of the quoted error bars of OGLE-TR-10, depending on its age. Using the same general theory, we show that the three recently detected hot-Neptune planets (GJ436, $\\rho$ Cancri, $\\mu$ Ara) may originate from more massive gas giants which have undergone significant evaporation. We thus suggest that hot-Neptunes and hot-Jupiters may share the same origin and evolution history. Our scenario provides testable predictions in terms of the mass-radius relationships of these hot-Neptunes.

I. Baraffe; G. Chabrier; T. S. Barman; F. Selsis; F. Allard; P. H. Hauschildt

2005-05-03

380

Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings  

Microsoft Academic Search

The Cassini Imaging 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-latitude upper troposphere, polar stratosphere, and northern aurora. We also describe previously unseen emissions arising from Io and Europa in eclipse, a giant volcanic plume over Io's

Carolyn C. Porco; Robert A. West; Alfred McEwen; Anthony D. Del Genio; Andrew P. Ingersoll; Peter Thomas; Steve Squyres; Luke Dones; Carl D. Murray; Torrence V. Johnson; Joseph A. Burns; Andre Brahic; Gerhard Neukum; Joseph Veverka; John M. Barbara; Tilmann Denk; Michael Evans; Joseph J. Ferrier; Paul Geissler; Paul Helfenstein; Thomas Roatsch; Henry Throop; Matthew Tiscareno; Ashwin R. Vasavada

2003-01-01