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1

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

NASA Astrophysics Data System (ADS)

In the core-accretion model, the nominal runaway gas-accretion phase brings most planets to multiple Jupiter masses. However, known giant planets are predominantly Jupiter mass bodies. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in the low-viscosity regime, or both. Here we explore the second way by using global, three-dimensional isothermal hydrodynamical simulations with eight levels of nested grids around the planet. In our simulations, the vertical inflow from the circumstellar disk (CSD) to the CPD determines the shape of the CPD and its accretion rate. Even without a prescribed viscosity, Jupiter's mass-doubling time is ~104 yr, assuming the planet at 5.2 AU and a Minimum Mass Solar Nebula. However, we show that this high accretion rate is due to resolution-dependent numerical viscosity. Furthermore, we consider the scenario of a layered CSD, viscous only in its surface layer, and an inviscid CPD. We identify two planet-accretion mechanisms that are independent of the viscosity in the CPD: (1) the polar inflow—defined as a part of the vertical inflow with a centrifugal radius smaller than two Jupiter radii and (2) the torque exerted by the star on the CPD. In the limit of zero effective viscosity, these two mechanisms would produce an accretion rate 40 times smaller than in the simulation.

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

2014-02-01

2

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

3

ACCRETION OF ROCKY PLANETS BY HOT JUPITERS  

SciTech Connect

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

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

2011-11-01

4

The Planet Jupiter  

NSDL National Science Digital Library

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

2007-06-06

5

The planet Jupiter (1970)  

NASA Technical Reports Server (NTRS)

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

Divine, N.

1971-01-01

6

Hot Jupiters from secular planet-planet interactions.  

PubMed

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

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

2011-05-12

7

RADIO INTERFEROMETRIC PLANET SEARCH. II. CONSTRAINTS ON SUB-JUPITER-MASS COMPANIONS TO GJ 896A  

SciTech Connect

We present results from the Radio Interferometric Planet search for companions to the nearby star GJ 896A. We present 11 observations over 4.9 yr. Fitting astrometric parameters to the data reveals a residual with peak-to-peak amplitude of {approx}3 mas in right ascension. This residual is well fit by an acceleration term of 0.458 {+-} 0.032 mas yr{sup -2}. The parallax is fit to an accuracy of 0.2 mas and the proper motion terms are fit to accuracies of 0.01 mas yr{sup -1}. After fitting astrometric and acceleration terms, residuals are 0.26 mas in each coordinate, demonstrating that stellar jitter does not limit the ability to carry out radio astrometric planet detection and characterization. The acceleration term originates in part from the companion GJ 896B, but the amplitude of the acceleration in declination is not accurately predicted by the orbital model. The acceleration sets a mass upper limit of 0.15 M{sub J} at a semimajor axis of 2 AU for a planetary companion to GJ 896A. For semimajor axes between 0.3 and 2 AU upper limits are determined by the maximum angular separation; the upper limits scale from the minimum value in proportion to the inverse of the radius. Upper limits at larger radii are set by the acceleration and scale as the radius squared. An improved solution for the stellar binary system could improve the exoplanet mass sensitivity by an order of magnitude.

Bower, Geoffrey C.; Bolatto, Alberto; Ford, Eric B.; Fries, Adam; Kalas, Paul; Sanchez, Karol; Viscomi, Vincent [Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720 (United States); Sanderbeck, Phoebe, E-mail: gbower@astro.berkeley.edu [Department of Physics, Brandeis University, Abelson-Bass-Yalem 107, MS 057, Waltham, MA 02453 (United States)

2011-10-10

8

Collisional evolution of a planetesimals disk perturbed by an embedded planet: a possible constraint on Jupiter's initial mass  

Microsoft Academic Search

An early proto-Jupiter may influence the formation of terrestrial planets during the phase of runaway growth. The transfer of random kinetic energy from a resonant region to the surrounding, due to collisions, increases the relative velocities in a disk of colliding planetesimals. This mechanism called \\

S. Charnoz; P. Thebault; A. Brahic; C. Ferrari

1999-01-01

9

Kepler constraints on planets near hot Jupiters  

PubMed Central

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

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

2012-01-01

10

Kepler constraints on planets near hot Jupiters  

SciTech Connect

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

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

2012-05-01

11

Kepler constraints on planets near hot Jupiters.  

PubMed

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

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

2012-05-22

12

Jupiter analogues and planets of active stars  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

13

Luminosity of young Jupiters revisited. Massive cores make hot planets  

NASA Astrophysics Data System (ADS)

Context. The intrinsic luminosity of young Jupiters is of high interest for planet formation theory. It is an observable quantity that is determined by important physical mechanisms during formation, namely, the structure of the accretion shock and, even more fundamentally, the basic formation mechanism (core accretion or gravitational instability). Aims: Our aim is to study the impact of the core mass on the post-formation entropy and luminosity of young giant planets forming via core accretion with a supercritical accretion shock that radiates all accretion shock energy (cold accretion). Methods: For this, we conduct self-consistently coupled formation and evolution calculations of giant planets with masses between 1 and 12 Jovian masses and core masses between 20 and 120 Earth masses in the 1D spherically symmetric approximation. Results: As the main result, it is found that the post-formation luminosity of massive giant planets is very sensitive to the core mass. An increase in the core mass by a factor 6 results in an increase in the post-formation luminosity of a 10-Jovian mass planet by a factor 120, indicating a dependency as mcore2-3. Due to this dependency, there is no single well-defined post-formation luminosity for core accretion, but a wide range, even for completely cold accretion. For massive cores ( 100 Earth masses), the post-formation luminosities of core accretion planets become so high that they approach those in the hot start scenario that is often associated with gravitational instability. For the mechanism to work, it is necessary that the solids are accreted before or during gas runaway accretion and that they sink during this time deep into the planet. Conclusions: We make no claims about whether such massive cores can actually form in giant planets especially at large orbital distances. But if they can form, it becomes difficult to rule out core accretion as the formation mechanism based solely on luminosity for directly imaged planets that are more luminous than predicted for low core masses. Instead of invoking gravitational instability as the consequently necessary formation mode, the high luminosity can also be caused, at least in principle, simply by a more massive core.

Mordasini, C.

2013-10-01

14

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

15

Jupiter Observation Campaign: Citizen Science at the Outer Planets  

Microsoft Academic Search

How can NASA Outreach help the citizen scientist? NASA Solar System Education and Public Outreach (EPO) may coordinate and disseminate a consistent process for receiving Jupiter and other outer planet observation data from citizen scientists.

J. H. Jones; A. S. Wessen; R. Pappalardo; S. Vance; P. Dyches; K. Beisser; J. Perry

2011-01-01

16

Heavy-element Enrichment of a Jupiter-mass Protoplanet as a Function of Orbital Location  

Microsoft Academic Search

One possible mechanism for giant planet formation is disk instability in which the planet is formed as a result of gravitational instability in the protoplanetary disk surrounding the young star. The final composition and core mass of the planet will depend on the planet's mass, environment, and the planetesimal accretion efficiency. We calculate heavy-element enrichment in a Jupiter-mass protoplanet formed

R. Helled; G. Schubert

2009-01-01

17

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

18

MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS  

SciTech Connect

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

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

2012-06-01

19

Could Jupiter be a carbon-rich planet?  

NASA Astrophysics Data System (ADS)

Motivated by recent spectroscopic observations suggesting that atmospheres of some extrasolar giant-planets are carbon-rich, i.e. carbon/oxygen ratio (C/O) ? 1, we find that the whole set of compositional data for Jupiter is consistent with the hypothesis that it be a carbon-rich giant planet. We show that the formation of Jupiter in the cold outer part of an oxygen-depleted disk (C/O ˜1) reproduces the measured Jovian elemental abundances at least as well as the hitherto canonical model of Jupiter formed in a disk of solar composition (C/O = 0.54). The resulting O abundance in Jupiter's envelope is then moderately enriched by a factor of ˜2 × solar (instead of ˜7 × solar) and is found to be consistent with values predicted by thermochemical models of the atmosphere.

Mousis, O.; Lunine, J. I.; Madhusudhan, N.; Johnson, T. V.

2012-12-01

20

Planet Masses and Densities  

NASA Astrophysics Data System (ADS)

The masses of Kepler planet candidates remain unknown until some dynamical technique measures the gravitational effect of that planet on either the star (with RV measurements) or other planets (with TTVs). Measuring planet masses is particularly important as, when combined with the transit-based planet radii, they yield the bulk density of the planets, constraining conditions in the interior, notably the amount of metal, rock, water, and gas. For planets smaller than 2 Earth-radii, the transition from Neptune-like to rocky planets is particularly intriguing, bearing on formation, evolution, and habitability. We report precise (2 m/s) Doppler RVs for 15 host stars of Kepler planet candidates. New RV techniques are now employed for faint stars of 13th mag, notably long-slit sky subtraction and statistical priors for the PSF and wavelength scale in the Doppler analysis. The RV observations are timed at moments near orbital quadrature to maximize the RV differences. We obtained 10-20 RVs for each of 15 host stars of Kepler planet candidates, with typical exposure times of 30 min. The RVs are fit with Keplerian models that include all transisting planets and their known ephemerides from the Kepler photometry. The two free parameters are only the masses of the planets and RV zero point. Both random and systematic errors will not be correlated with orbital phase, ensuring that the RV signal-to-noise improves as the square root of the number of RV observations. Orbital fits provide planet mass, density, and in some cases contraints on eccentricity. For RV non-detections, MCMC analyses provide upper limits to planet mass and density.

Marcy, Geoffrey W.

2012-05-01

21

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

SciTech Connect

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

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

2012-06-20

22

Jupiter Observation Campaign: Citizen Science at the Outer Planets  

Microsoft Academic Search

NASA Solar System Education and Public Outreach (E\\/PO) will coordinate and disseminate a consistent process for receiving Jupiter observation data from citizen scientists. This may include a public repository or network matching scientists with citizen scientists who want to provide needed observations in a standard and consistent format. This will be a good Outer Planet mission contribution to the science

J. Houston. Jones; A. Wessen; Robert Pappalardo; Kerri Beisser; Preston Dyches

2010-01-01

23

The Heavy-element Masses of Extrasolar Giant Planets, Revealed  

NASA Astrophysics Data System (ADS)

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

Miller, Neil; Fortney, Jonathan J.

2011-08-01

24

Astronomical Papers. Volume XXI. Part I. The Orbit of Polyhymnia and the Mass of Jupiter.  

National Technical Information Service (NTIS)

The motion of Polyhymnia is sensitive to the mass of Jupiter because of nearly commensurate mean motions and actual close approaches. In the study, observations of the minor planet, extending from 1854 to 1969, are discussed and compared with numerically ...

P. M. Janiczek

1971-01-01

25

N-body Simulations of Terrestrial Planet Formation under the Influence of a Hot Jupiter  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

26

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¸?niak, R.; Duda, A. M.; Drzazga, E. A.

2014-06-01

27

Mass Growth and Evolution of Giant Planets on Resonant Orbits  

NASA Astrophysics Data System (ADS)

A pair of giant planets that tidally interact with a gaseous disk may undergo convergent orbital migration and become locked into a mean motion resonance (MMR). If the planet masses are similar to those of Jupiter and Saturn, typical after-formation conditions in protoplanetary disks lead to capture in the 2:1 MMR. Larger gas densities may cause capture in the 3:2 MMR instead. Here we present the results of hydrodynamical models of the evolution of a pair of planets, initially locked in the 2:1 or 3:2 MMR, as they interact with each other and the disk. We focus on the issue of ongoing gas accretion, the importance of which depends on the local disk mass. The high density required for capture in the 3:2 MMR causes a rapid change of the masses and mass ratio. Ensuing planet-planet interactions raises both orbital eccentricities and leads to scattering episodes and to the ejection of one of the planets from the system. Conditions compatible with 2:1 MMR locking can also lead to a more or less substantial growth of the planet masses, depending on the disk density. However, for planets orbiting in the 1 AU region, the resonant configuration appears stable up to masses of about 5 Jupiter's masses. Support from NASA Outer Planets Research Program and NASA Origins of Solar Systems Program is gratefully acknowledged.

Marzari, Francesco; D'Angelo, G.

2013-10-01

28

THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED  

SciTech Connect

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

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

2011-08-01

29

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

30

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

31

Jupiter  

NASA Technical Reports Server (NTRS)

This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. The colors have been enhanced to bring out detail. Zones of light-colored, ascending clouds alternate with bands of dark, descending clouds. The clouds travel around the planet in alternating eastward and westward belts at speeds of up to 540 kilometers per hour. Tremendous storms as big as Earthly continents surge around the planet. The Great Red Spot (oval shape toward the lower-left) is an enormous anticyclonic storm that drifts along its belt, eventually circling the entire planet.

1990-01-01

32

The helium mass fraction in Jupiter's atmosphere.  

PubMed

On 7 December 1995, the NASA Galileo probe provided in situ measurements of the helium abundance in the atmosphere of Jupiter. A Jamin interferometer measured the refractive index of the jovian atmosphere in the pressure region from 2 to 14 bars. These measurements indicate that the atmospheric helium mole fraction is 0.136 +/- 0.004. The corresponding helium mass fraction is slightly below the presolar value, which suggests that separation of helium from hydrogen in Jupiter's interior is only in its early stages. PMID:8629017

von Zahn, U; Hunten, D M

1996-05-10

33

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

34

Jupiter  

Microsoft Academic Search

\\u000a Among the outer planets, we find the coldest temperatures and fiercest winds. The gas giants – Jupiter, Saturn, Uranus, and\\u000a Neptune – offer us the most alien skies in our Solar System. Here, where the Sun glows like a distant ember, storms large\\u000a enough to swallow the entire Earth rage for decades. It is a region of extremes, of bitter

Michael Carroll

35

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

36

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

PubMed

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

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

2011-07-14

37

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

38

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

39

The effect of Jupiter's mass growth on satellite capture. Retrograde case  

Microsoft Academic Search

Gravitational capture can be used to explain the existence of the irregular satellites of giants planets. However, it is only the first step since the gravitational capture is temporary. Therefore, some kind of non-conservative effect is necessary to to turn the temporary capture into a permanent one. In the present work we study the effects of Jupiter mass growth for

E. Vieira Neto; O. C. Winter; T. Yokoyama

2004-01-01

40

Orbital migration of giant planets induced by gravitationally unstable gaps: the effect of planet mass  

NASA Astrophysics Data System (ADS)

It has been established that self-gravitating disc-satellite interaction can lead to the formation of a gravitationally unstable gap. Such an instability may significantly affect the orbital migration of gap-opening perturbers in self-gravitating discs. In this paper, we extend the two-dimensional hydrodynamic simulations of Lin & Papaloizou to investigate the role of the perturber or planet mass on the gravitational stability of gaps and its impact on orbital migration. We consider giant planets with planet-to-star mass ratio q ? Mp/M* ? [0.3, 3.0] × 10-3 (so that q = 10-3 corresponds to a Jupiter mass planet if M* = M?), in a self-gravitating disc with disc-to-star mass ratio Md/M* = 0.08, aspect ratio h = 0.05 and Keplerian Toomre parameter Qk0 = 1.5 at 2.5 times the planet's initial orbital radius. These planet masses correspond to tilde{q}in [0.9, 1.7], where tilde{q} is the ratio of the planet Hill radius to the local disc scale-height. Fixed-orbit simulations show that all planet masses we consider open gravitationally unstable gaps, but the instability is stronger and develops sooner with increasing planet mass. The disc-on-planet torques typically become more positive with increasing planet mass. In freely migrating simulations, we observe faster outward migration with increasing planet mass, but only for planet masses capable of opening unstable gaps early on. For q = 0.0003 (tilde{q}=0.9), the planet undergoes rapid inward type III migration before it can open a gap. For q = 0.0013 (tilde{q}=1.5) we find it is possible to balance the tendency for inward migration by the positive torques due to an unstable gap, but only for a few 10 s of orbital periods. We find the unstable outer gap edge can trigger outward type III migration, sending the planet to twice its initial orbital radius on dynamical time-scales. We briefly discuss the importance of our results in the context of giant planet formation on wide orbits through disc fragmentation.

Cloutier, Ryan; Lin, Min-Kai

2013-09-01

41

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

NASA Astrophysics Data System (ADS)

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

Houston Jones, J.; Dyches, P.

2012-12-01

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

Star-Planet Interactions: The Tidal and Magnetic Influence of Hot Jupiters  

NASA Astrophysics Data System (ADS)

The interacting processes taking place between a giant planet orbiting its star within 10 stellar radii (also known as a "hot Jupiter") have been getting increasing attention both observationally and theoretically. Our work has shown that such a short-period planet can induce activity on the upper atmosphere of its host star through both tidal and magnetic star-planet interactions (SPI). Evidence for magnetic SPI includes a diverse array of photometric, spectroscopic and spectropolarimetric studies. Because of the small separation (< 0.1 AU), many of the hot Jupiters lie within the Alfven radius of their host stars, allowing direct magnetic interaction with the stellar surface. Models show both the stellar and planetary magnetic fields being strongly affected, possibly influencing the magnetic activity of both bodies, as well as modifying irradiation and non-thermal and dynamical processes. In addition, a hot Jupiter's tidal influence on its star may increase the stellar rotation rate and thus also increase the global stellar activity level. Our recent work has shown that stars with hot Jupiters have twice the UV emission than stars with planets in wider orbits, which is also anti-correlated with the stellar synchronization time scales. Even though the stars with hot Jupiters are not fully synchronized (full synchronization in most cases will take longer than the age of the Universe), they have already undergone some increase in rotation rate, provided that the planets migrated early on in the system's history. Studying both tidal and magnetic star-planet interactions aids our understanding of the formation, migration and evolution of hot Jupiters, and provides the best-available probe of exoplanetary magnetic fields.

Shkolnik, Evgenya

2010-05-01

44

Quasi-analytical solutions for APSIDAL motion in the three-body problem: Sun -- minor planet -- Jupiter  

Microsoft Academic Search

This paper deals with the effect of a third body on the apsidal motion of two bodies. The specific case involves a third body-planet Jupiter and the apsidal line motion of a minor planet that orbits the Sun and has its apsidal line go through the major axis of an ellipse. The third body (Jupiter) which satisfies the Langrangian solution

Wan Xian Wang; N. Y. Misconi

1999-01-01

45

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

46

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

47

A Short-period Censor of Sub-Jupiter Mass Exoplanets with Low Density  

NASA Astrophysics Data System (ADS)

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 RJ ) 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 MJ or with radius between 0.25 and 1.0 RJ are known with P orb < 2.5 days. This clustering is not predicted by current theories of planet formation and evolution, which we also review briefly.

Szabó, Gy. M.; Kiss, L. L.

2011-02-01

48

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

NASA Astrophysics Data System (ADS)

This paper presents the results of a comprehensive wide-field search for transiting ``hot Jupiter'' planets (gas giant planets with an orbital period in the range 1day<=P<=16days) in the globular cluster 47 Tuc. Motivated by the detection of the transit in HD 209458 and the apparent lack of planetary detections in the core of 47 Tuc by Gilliland and coworkers, this work further addresses the question of giant planet frequency in 47 Tuc by observing from the ground a 52'×52' field centered on the cluster. Hence, this work is most sensitive to the uncrowded outer regions, where the stellar densities are significantly lower than in the core, and concentrates on 21,920 main-sequence stars within 2.5 mag of the cluster turnoff (hence approaching the solar value in mass). Our work comprises the largest ground-based transit search of a globular cluster to date, incorporating a 33 night time series that allows us excellent sensitivity to detect hot Jupiter planets. Detailed Monte Carlo simulations incorporating the actual temporal sampling and photometric precision of the data predict that seven planets with orbital periods in the range 1-16 days should be present in our data set if 47 Tuc has the same planetary frequency as that observed in the solar neighborhood. A detailed search utilizing a matched filter algorithm, developed specifically for this project, found no transit events. This 3.3 ? result is consistent with the Hubble Space Telescope cluster core null detection of Gilliland and coworkers. Our result indicates that system metallicity rather than crowding is the dominant effect inhibiting hot Jupiter formation in this environment. The 33 night data set used for this result also led to the detection of 100 variable stars, including 69 new discoveries, which are presented in a companion paper.

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

2005-02-01

49

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

50

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

51

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

52

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?

53

Richardson number constraints for the Jupiter and outer planet wind regime  

Microsoft Academic Search

Present theories of the dynamics of the outer planet atmospheres are limited by the absence of direct observations of the wind and temperature layering below their visible cloud decks. We show that if the potential vorticity is assumed to be small at low latitudes, then cloud-tracked wind measurements of the equatorial flow on Jupiter, Saturn, Uranus, and Neptune can be

Michael Allison; Anthony D. Del Genio; Wei Zhou

1995-01-01

54

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

55

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

56

From Very Low Mass Stars to Extrasolar Planets  

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

57

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

58

Search for X rays from the planet Jupiter.  

NASA Technical Reports Server (NTRS)

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

Hurley, K. C.

1972-01-01

59

Astronomers Announce the Most Earth-Like Planet Yet Found Outside the Solar System  

NSF Publications Database

... its low mass precludes it from retaining gas like Jupiter. Three other purported rocky planets have ... gas giant about twice the mass of Jupiter. Then, in 2001, they reported a second planet, another gas ...

60

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

61

High precision spectropolarimetry of stars and planets. II Spectropolarimetry of Jupiter and Saturn  

NASA Astrophysics Data System (ADS)

A rise in the linear polarization detected from the integrated disc of Jupiter across the 7270 Å methane band is confirmed. The effect is also shown to be present across the same band for Saturn. A large enhancement in the circular polarization of Saturn at phase angle 2°.7 has been seen, and its remarkable wavelength dependence studied. These observations provide useful constraints for the more sophisticated models that are clearly needed for the atmospheres of these planets.

Smith, R. J.; Wolstencroft, R. D.

1983-10-01

62

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

63

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

64

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

65

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

PubMed

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

Kortenkamp, S J; Wetherill, G W

2000-01-01

66

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

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

67

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

68

Extrasolar planets around intermediate mass stars  

NASA Astrophysics Data System (ADS)

One of the earliest hints for extrasolar planets came with the discovery almost 15 years ago of low amplitude, long period radial velocity (RV) variations in several K giant stars, ? Gem, ? Tau (Aldebaran) and ? Boo. Since then it has been confirmed that for ? Gem (stellar mass =1.7 Modot) these RV variations are due to a planetary companion. Aldebaran is another K giant star showing long-lived (>26 years) and coherent RV variations. These are most likely due to a planetary companion having a mass of 9 MJup using an estimated mass of 2.5 Modot for the star. Giant stars like ? Tau and ? Gem offer us the possibility of studying the process of planet formation around stars more massive than the sun. The main sequence stars with masses >1.2 Modot are ill-suited for RV surveys as there are few spectral lines for measuring the RV and these are often broadened by high rates of stellar rotation. Currently over 20 intermediate mass giant stars are known to host extrasolar planets. This sample is sufficiently large that we can begin to look at the overall properties of planets around intermediate mass stars. These suggest that more massive stars may have more massive planets that the orbital eccentricities for their extrasolar planets show the wide range of eccentricities seen for main sequence, solar mass stars, and that unlike for main sequence stars there seems to be no preference for metal rich intermediate mass stars to host extrasolar planets.

Hatzes, A. P.

2008-08-01

69

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.

70

Dynamics of the Jupiter Trojans with Saturn's perturbation in the present configuration of the two planets  

NASA Astrophysics Data System (ADS)

The dynamics of the two Jupiter triangular libration points perturbed by Saturn is studied in this paper. Unlike some previous works that studied the same problem via the pure numerical approach, this study is done in a semianalytic way. Using a literal solution, we are able to explain the asymmetry of two orbits around the two libration points with symmetric initial conditions. The literal solution consists of many frequencies. The amplitudes of each frequency are the same for both libration points, but the initial phase angles are different. This difference causes a temporary spatial asymmetry in the motions around the two points, but this asymmetry gradually disappears when the time goes to infinity. The results show that the two Jupiter triangular libration points should have symmetric spatial stable regions in the present status of Jupiter and Saturn. As a test of the literal solution, we study the resonances that have been extensively studied in Robutel and Gabern (Mon Not R Astron Soc 372:1463-1482, 2006). The resonance structures predicted by our analytic theory agree well with those found in Robutel and Gabern (Mon Not R Astron Soc 372:1463-1482, 2006) via a numerical approach. Two kinds of chaotic orbits are discussed. They have different behaviors in the frequency map. The first kind of chaotic orbits (inner chaotic orbits) is of small to moderate amplitudes, while the second kind of chaotic orbits (outer chaotic orbits) is of relatively larger amplitudes. Using analytical theory, we qualitatively explain the transition process from the inner chaotic orbits to the outer chaotic orbits with increasing amplitudes. A critical value of the diffusion rate is given to separate them in the frequency map. In a forthcoming paper, we will study the same problem but keep the planets in migration. The time asymmetry, which is unimportant in this paper, may cause an observable difference in the two Jupiter Trojan groups during a very fast planet migration process.

Hou, Xiyun; Scheeres, Daniel J.; Liu, Lin

2014-06-01

71

Effect of Jupiter's mass growth on satellite capture. The prograde case  

Microsoft Academic Search

We study the effects of Jupiter mass growth in order to permanently capture prograde satellites. Adopting the restricted three-body problem, Sun-Jupiter-Particle, we performed numerical simulations backward in time while considering the decrease in Jupiter's mass. We considered the particle's initial conditions to be prograde, at pericenter, in the region 100 {R}jupiter <= a<= 400 {{R}jupiter} and 0<= e<= 0.5. The

E. Vieira Neto; O. C. Winter; T. Yokoyama

2006-01-01

72

Gravity Drilling of Mass Differentiated Planets  

Microsoft Academic Search

Analysis of satellite-measured gravity and topography can provide crust-to-core mass variation models for considering the geologic evolution of the poorly understood crustal and subcrustal features of the terrestrial planets.

L. V. Potts; T. Leftwich; H. R. Kim; S.-C. Han; R. R. B. von Frese

2003-01-01

73

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

74

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

NASA Astrophysics Data System (ADS)

We present a strong case for a transiting hot Jupiter planet identified during a single-field transit survey toward the Lupus Galactic plane. The object, Lupus-TR-3b, transits a V=17.4 K1 V host star every 3.91405 days. 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 Msolar and 0.82 +/- 0.05 Rsolar, respectively. Limb-darkened transit fitting yields a companion radius of 0.89+/-0.07 RJ and an orbital inclination of 88.3+1.3-0.8 deg. Magellan 6.5 m MIKE radial velocity measurements reveal a 2.4 ? K = 114 +/- 25 m s-1 sinusoidal variation in phase with the transit ephemeris. The resulting mass is 0.81 +/- 0.18 MJ and density 1.4 +/- 0.4 g cm-3. Y-band PANIC image deconvolution reveals 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.

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

2008-03-01

75

Heavyweight Champion: Jupiter  

NSDL National Science Digital Library

Learners will 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. They compare the features of different planets to determine which characteristics cause a planet to have more or less gravity. 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.

76

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

NASA Astrophysics Data System (ADS)

We report on the first extra-solar planet discovered with the brand new HARPS instrument. The planet is a typical ``hot Jupiter'' with m2 sin i=0.62 MJup and an orbital period of 3.39 days, but from the photometric follow-up of its parent star HD 330075 we can exclude the presence of a transit. The induced radial-velocity variations exceed 100 m s-1 in semi-amplitude and are easily detected by state-of-the-art spectro-velocimeters. Nevertheless, the faint magnitude of the parent star (V=9.36) benefits from the efficient instrument: with HARPS less than 10 observing nights and 3 h of total integration time were needed to discover the planet and characterize its orbit. The orbital parameters determined from the observations made during the first HARPS run in July 2003 have been confirmed by 7 additional observations carried out in February 2004. The bisector analysis and a photometric follow-up give no hint for activity-induced radial-velocity variations, indicating that the velocity curve is best explained by the presence of a low-mass companion to the star. In this paper we present a set of 21 measurements of excellent quality with weighted rms as low as 2.0 m s-1. These measurements lead to a well defined orbit and consequently to the precise orbital parameters determination of the extra-solar planet HD 330075 b. Based on observations made with the HARPS instrument on the ESO 3.6 m telescope at the La Silla Observatory under programme ID 72.C-0488

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

2004-08-01

77

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

NASA Astrophysics Data System (ADS)

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

Storch, Natalia I.; Lai, Dong

2014-02-01

78

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

SciTech Connect

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

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

2012-07-15

79

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

80

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

81

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

82

TEXES Spectral Mapping of Jupiter and Saturn and the Origins of Giant Planet Nitrogen  

NASA Astrophysics Data System (ADS)

We report spectral mapping of the atmospheres of Jupiter and Saturn in February 2013 using the Texas Echelon cross Echelle Spectrograph (TEXES, [1]) mounted on NASA's Infrared Telescope Facility (IRTF). The purpose of these observations was (i) to study jovian meteorology via measurements of temperature, wind shear, humidity (i.e., ammonia content) and cloud coverage; (ii) to assess the aftermath of Saturn's northern 2010-2011 storm, including the continued existence of the stratospheric anticyclonic vortex [2]; and (iii) to determine precise estimates of the 15N/14N ratio on both planets to constrain the origins of nitrogen to the gas giants. Mid-infrared observations of this nature complement spacecraft observations from Cassini, Juno and, ultimately, JUICE.

Fletcher, L. N.; Greathouse, T. K.; Orton, G. S.; Irwin, P. G. J.; Sinclair, J. A.

2013-09-01

83

The Low Mass of Mars: First Evidence of Early Gas-Driven Migration by Jupiter  

NASA Astrophysics Data System (ADS)

Numerical simulations of planetary accretion have succeeded in matching most of the physical and orbital properties of the terrestrial planets with one glaring exception: they categorically form Mars analogs that are roughly an order of magnitude too massive (Raymond et al. 2009). The initial conditions that best reproduce the mass of Mars require that the inner planetesimal disk had an outer edge at 1 Astronomical Unit (AU) (Hansen 2009). To date, no mechanism has been shown to create this edge and remain compatible with the current-day solar system, in particular the existence of the asteroid belt. Here we show that a substantial gas-driven radial migration of the giant planets is the needed mechanism. Hydrodynamical simulations show that the evolution of Jupiter and Saturn in a gas-disk generically leads to a two-stage, inward-then-outward, migration where the extent of each stage of migration depends on a priori unconstrained disk parameters (Masset & Snellgrove 2001, Morbidelli et al. 2007, Pierens & Nelson 2008). We demonstrate with numerical simulations that, if Jupiter migrated inwards to 1.5 AU before migrating out towards its current location, its gravitational influence would truncate the inner planetesimal disk at 1 AU. The resulting disk naturally reproduces all the terrestrial planets including Mars. During the giant planets' migration, the asteroid belt is emptied and later re-populated from two distinct parent populations. This provides the first dynamical explanation for the current dichotomy of physical properties of the main asteroid belt, with anhydrous asteroids (S-type) in the inner part and primitive asteroids (C-type) in the outer part (Gradie & Tedesco 1982). Our model links the origin of the inner solar system -- explaining the mass of Mars and the properties of the asteroid belt -- to a realistic evolution of the giant planets. Thus Mars and the asteroid belt provide the first evidence for an early solar system evolution characterized by substantial gas-driven orbital migration of the giant planets, similar to what is inferred for extrasolar planet systems (Armitage 2007).

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

2010-12-01

84

Mass-Radius Relationships for Very Low Mass Gaseous Planets  

NASA Astrophysics Data System (ADS)

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

Batygin, Konstantin; Stevenson, David J.

2013-05-01

85

MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS  

SciTech Connect

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

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

2013-05-20

86

Families of periodic orbits in the general three-body problem for the Sun-Jupiter-Saturn mass-ratio and their stability  

Microsoft Academic Search

Several families of planar planetary-type periodic orbits in the general three-body problem, in a rotating frame of reference, for the Sun-Jupiter-Saturn mass-ratio are found and their stability is studied. It is found that the configuration in which the orbit of the smaller planet is ‘inside’ the orbit of the larger planet is, in general, more stable.

P. Delibaltas

1976-01-01

87

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

88

Searching for Earth Mass Planet via Microlensing  

Microsoft Academic Search

Core accretion models are today the best alternative to explain the formation of planetary systems: accretion of planetesimals leads to the formation of cores, which then start to accrete gas from the primitive nebula (Laughlin G., et al., 2004 ApJ 612, L73). This scenario predicts in the case of M stars a preferred formation of low mass planets (Earth to

Jean-Philippe Beaulieu; A. Cassan

2007-01-01

89

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

NASA Astrophysics Data System (ADS)

Simulations of physical systems are widely available online, with no cost, and are ready to be used in our classrooms.1,2 Such simulations offer an accessible tool that can be used for a range of interactive learning activities. The Jovian Moons Applet2 allows the user to track the position of Jupiter's four Galilean moons with a variety of viewing options. For this activity, data are obtained from the orbital period and orbital radii charts. Earlier experiments have used telescopes to capture the orbital motion of the Galilean moons,3 although observation of astronomical events and the measurement of quantities may be difficult to achieve due to a combination of cost, training, and observing conditions. The applet allows a suitable set of data to be generated and data analysis that verifies Kepler's third law of planetary motion, which leads to a calculated value for the mass of Jupiter.

Bates, Alan

2013-10-01

90

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

91

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

92

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

NASA Astrophysics Data System (ADS)

We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V = 13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49 M J, and radii of 1.24, 1.43, and 1.28 R J. The stellar hosts have masses of 0.94, 1.26, and 1.28 M ?. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, including the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494 ± 0.081, and a minimum mass of 4.0 M J. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5 ± 6.3 m s-1 is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0 M J, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NOAO (A284Hr) and NASA (N154Hr, N108Hr).

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

2014-06-01

93

WFIRST Planet Masses from Microlens Parallax  

NASA Astrophysics Data System (ADS)

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

Yee, J. C.

2013-06-01

94

WFIRST PLANET MASSES FROM MICROLENS PARALLAX  

SciTech Connect

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

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

2013-06-20

95

Prospects for Improving the Masses of Minor Planets.  

National Technical Information Service (NTIS)

Among the largest uncertainties in the fundamental constants of astronomy are the masses of the minor planets. They constitute the largest source of uncertainty in the ephemerides of the inner planets. Few asteroid masses are known with an uncertainty of ...

J. L. Hilton

2007-01-01

96

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

97

Planet Hunter: A Astrometric Search of 65 Nearby Stars for Earth-Mass Planets  

NASA Astrophysics Data System (ADS)

Planet Hunter is a proposed spaceborne optical interferometer that can measure positions of bright stars with a precision of 1 microarcsec relative to reference stars. It can detect Earth-mass planets orbiting 1 AU from Sun-like stars within 20 pc. Planet Hunter can detect rocky planets in the habitable zone of 65 nearby FGK stars and determine the planet masses unambiguously, as well as masses of ice-giants and gas giants within 5 AU. Planet Hunter can also determine the full set orbital parameters of the planets it detects, including eccentricity and the 7-D orbit. The resulting ephemeris can predict the intervals of time when the planet resides outside the inner working angle, making spectroscopy possible by future imaging missions. The program is currently a NASA Astrophysics Strategic Mission Concept Study, carried out mostly at JPL.

Marcy, Geoffrey W.

2009-01-01

98

Habitable Planets: Observational Arguments  

NASA Astrophysics Data System (ADS)

Observations of extrasolar planets and protostellar disks suggest that rocky worlds form commonly around young stars. At least 8% of stars are observed to have saturn- and jupiter-mass planets within 3 AU, and more planets are likely beyond 3 AU. The mass distribution of planets rises steeply with decreasing mass (Marcy & Butler 2000), implying that more small planets form than giant ones. Elliptical, rather than circular, orbits predominate among the 35 known planets beyond 0.2 AU. New Doppler and astrometric techniques may reveal planets having masses as low as 10 Earth-masses. Protoplanetary disks surround over half of young stars, with disk masses typically over 10X that of Jupiter. Their energy distributions from IR and mm-wave observations yield dust emissivities that imply the rapid growth (within 0.1 Myr) of dust particles to millimeter size. Thus, theoretical predictions of quick growth of rocky planets is supported. One may rationally estimate that 50% of all stars form with a retinue of rocky orbiting bodies. However, a nemesis looms for the survival of earths: dynamical scattering and ejection. The ubiquity of eccentric orbits among jupiters orbiting from 0.2--3 AU suggests that gravitational scattering among planets and planetesimals is a common phenomenon (see the following presentation by H. Levison). If so, the circular orbits and survival of the lowest mass, terrestrial planets are jeopardized. We acknowledge funding from NASA, NSF, and Sun Microsystems.

Marcy, G.; Butler, R. P.; Vogt, S. S.; Fischer, D. A.

2000-12-01

99

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

100

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

101

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

NASA Technical Reports Server (NTRS)

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

Marley, Mark Scott; Sengupta, Sujan

2012-01-01

102

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

103

Mass Measurements for Microlens Planets with WFIRST/AFTA  

NASA Astrophysics Data System (ADS)

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

Yee, Jennifer C

2014-06-01

104

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

SciTech Connect

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

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

2010-12-15

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

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

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

On the Possibility of Wandering Planets Existence.  

National Technical Information Service (NTIS)

The possibility of wandering planet formation by protostar matter expulsion and escape from the protostar gravitational field is discussed. Depending on the stellar wind velocity of the radiation pressure, masses of values similar to Earth or Jupiter mass...

L. M. Mukhin V. C. Strelnitsky

1973-01-01

109

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.

110

Catastrophic Mass Loss Histories of Disintegrating Kepler Planets  

NASA Astrophysics Data System (ADS)

Short-period rocky extrasolar planets can have dayside temperatures surpassing 2000K, hot enough to sublimate rock and create a high-metallicity atmosphere. This atmosphere can escape via a thermal wind. As the atmosphere expands and cools, micron-sized dust can recondense out of the escaping high-Z gas. Dust absorbs a fraction of the incident starlight and heats the gas by gas-grain collisions. We present a hydrodynamic model of atmospheric escape from low-mass rocky planets that includes tidal gravity, variable grain condensation, and realistic heating and cooling of gas. We find that the mass loss rate depends so strongly on planet mass that the planet can lose the majority of its primordial mass within the last 1% of its lifetime. This calculation is of interest in light of the recently discovered planet candidate KIC 12557548b in the Kepler data. Stellar occultations for this source occur every 15.7 hours but vary in depth from a maximum of 1.3% to less than 0.2% in an apparently stochastic fashion. This source may represent a disintegrating rocky planet in its final death throes. Occultations are not caused by the planet itself, but by a time-variable dusty outflow enshrouding the planet. Our radiative/hydrodynamic calculations further secure this interpretation and give a planet mass 5 Gyr ago of 0.07 M?, and a mass of 0.01 M? today.

Chiang, Eugene; Perez-Becker, D.

2012-10-01

111

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

Microsoft Academic Search

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

C. Sotin; O. Grasset; A. Mocquet

2007-01-01

112

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

113

Catastrophic Mass Loss Histories of Disintegrating Kepler Planets  

NASA Astrophysics Data System (ADS)

Short-period rocky extrasolar planets can have dayside temperatures surpassing 2000K, hot enough to sublimate rock and create a high-metallicity atmosphere. This atmosphere can escape via a thermal wind. As the atmosphere expands and cools, micron-sized dust can recondense out of the escaping high-Z gas. Dust absorbs a fraction of the incident starlight and heats the gas by gas-grain collisions. We present a hydrodynamic model of atmospheric escape from low-mass rocky planets that includes tidal gravity, variable grain condensation, and realistic heating and cooling of gas. We find that the mass loss rate depends so strongly on planet mass that the planet can lose the majority of its primordial mass within the last 1% of its lifetime. This calculation is of interest in light of the recently discovered planet candidate KIC 12557548b in the Kepler data. Stellar occultations for this source occur every 15.7 hours but vary in depth from a maximum of 1.3% to less than 0.2% in an apparently stochastic fashion. This source may represent a disintegrating rocky planet in its final death throes. Occultations are not caused by the planet itself, but by a time-variable dusty outflow enshrouding the planet. Our radiative/hydrodynamic calculations further secure this interpretation and give a planet mass 5 Gyr ago of 0.1 M_Earth, and a mass of 0.01 M_Earth today. Mass history of KIC 12557548b. Planetary lifetimes of several Gyr at the present-day orbit are possible due to the strong dependence of the evaporative mass loss rate on planetary mass. For a 5-Gyr-old system, the initial planet mass is 0.1 M_Earth.

Perez-Becker, D.; Chiang, E.

2012-12-01

114

Exotic Earths: forming habitable worlds with giant planet migration.  

PubMed

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

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

2006-09-01

115

Detection of Earth-mass and super-Earth Trojan planets using transit timing variation method  

NASA Astrophysics Data System (ADS)

We have carried out an extensive study of the possibility of the detection of Earth-mass and super-Earth Trojan planets using transit timing variation method with the Kepler space telescope. We have considered a system consisting of a transiting Jovian-type planet in a short period orbit, and determined the induced variations in its transit timing due to an Earth-mass/super-Earth Trojan planet. We mapped a large section of the phase space around the 1:1 mean-motion resonance and identified regions corresponding to several other mean-motion resonances where the orbit of the planet would be stable. We calculated transit timing variations (TTVs) for different values of the mass and orbital elements of the transiting and perturbing bodies as well as the mass of central star, and identified orbital configurations of these objects (ranges of their orbital elements and masses) for which the resulted TTVs would be within the range of the variations of the transit timing of Kepler's planetary candidates. Results of our study indicate that in general, the amplitudes of the TTVs fall within the detectable range of timing precision obtained from the Kepler's long-cadence data, and depending on the parameters of the system, their magnitudes may become as large as a few hours. The probability of detection is higher for super-Earth Trojans with slightly eccentric orbits around short-period Jovian-type planets with masses slightly smaller than Jupiter. We present the details of our study and discuss the implications of its results.

Haghighipour, Nader; Capen, Stephanie; Hinse, Tobias C.

2013-09-01

116

Formation of giant planets  

NASA Astrophysics Data System (ADS)

We present calculations of giant planet formation based on extended core-accretion planet formation models taking into account disk structure and evolution and migration of the protoplanet. We show that these models lead to giant planet formation timescales compatible with disk lifetimes. Using these models, we show that we can reproduce the bulk internal structure of Jupiter and Saturn, as well as the enrichment in volatile species measured in situ by the Galileo probe (for Jupiter), and from the Earth (for Saturn). We then apply these models to the formation of the three Neptune mass planet system recently discovered by the HARPS collaboration (Lovis et al. 2006), and show that the two outer planets are likely to have accreted large amounts of water ice during their formation. Finally, the comparison with the extrasolar planets will be presented by C. Mordasini (this meeting, abstract EPSC2006-A-00672) using a Monte-Carlo approach.

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

117

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

SciTech Connect

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

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

2013-07-01

118

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

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

119

High dispersion spectra of the outer planets. I. Jupiter in the visual and red  

Microsoft Academic Search

Our high dispersion spectrograms of Jupiter partially resolve the red methane and ammonia bands and show new, weak lines. At times the Jovian ammonia and methane gases do not co-rotate with the cloud layer as evidenced by the anomalous inclination of their absorption lines. The measures are discussed in detail. The Jovian CH4 lines in the lambda 6190 band have

Hyron Spinrad; Laurence M. Trafton

1963-01-01

120

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

121

Detecting earth-mass planets with gravitational microlensing  

Microsoft Academic Search

We show that Earth-mass planets orbiting stars in the Galactic disk and bulge can be detected by monitoring microlensed stars in the Galactic bulge. The star and its planet act as a binary lens which generates a light curve that can differ substantially from the light curve due only to the star itself. We show that the planetary signal remains

David P. Bennett; Sun Hong Rhie

1996-01-01

122

Low-Mass Companions for Five Solar-Type Stars From the Magellan Planet Search Program  

NASA Astrophysics Data System (ADS)

We report low-mass companions orbiting five solar-type stars that have emerged from the Magellan precision Doppler velocity survey, with minimum (Msin i) masses ranging from 1.2 to 25 M JUP. These nearby target stars range from mildly metal-poor to metal-rich, and appear to have low chromospheric activity. The companions to the brightest two of these stars have previously been reported from the CORALIE survey. Four of these companions (HD 48265-b, HD 143361-b, HD 28185-b, and HD 111232-b) are low-mass Jupiter-like planets in eccentric intermediate- and long-period orbits. On the other hand, the companion to HD 43848 appears to be a long-period brown dwarf in a very eccentric orbit. Based on observations obtained with the Magellan Telescopes, operated by the Carnegie Institution, Harvard University, University of Michigan, University of Arizona, and the Massachusetts Institute of Technology.

Minniti, Dante; Butler, R. Paul; López-Morales, Mercedes; Shectman, Stephen A.; Adams, Fred C.; Arriagada, Pamela; Boss, Alan P.; Chambers, John E.

2009-03-01

123

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

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

The planet Jupiter in 1979-1980 - The observers and their works  

NASA Astrophysics Data System (ADS)

Techniques for validly comparing astronomical observations of Jupiter in the period 1979-1980 are defined, and details of the observations are presented. The necessity of establishing a common scale of observations, in terms of the measurements of the bands of Jupiter and the anotation of limb observations in all reports is stressed. The opposition of Jupiter with Regulus and Mars is described, together with phenomena occurring in the south south temperate zone, the south south temperate band, and zone south of the south temperate zone. Observations of the south temperate band, as well as the two equatorial bands with a 60 mm lens, are reviewed. Shape changes and positions of the White Oval Spots are reported, and detection of disturbances in the south tropical zone at 200 deg is noted. The traverse of the Great Red Spot across the viewed hemisphere is traced and found to remain stationary at 58 deg. The persistence of a white spot in the equatorial zone south and dark spots in the north north equatorial band are mentioned.

Neel, R.

1983-01-01

126

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

127

Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b from disk Morphology  

NASA Astrophysics Data System (ADS)

Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M pl < 3M J, an orbital semimajor axis a pl > 101.5 AU, and an orbital eccentricity e pl = 0.11-0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a ? 133 AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e ? 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of ~ 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to ~ 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties may be large. If the apsidal misalignment proves real, our calculated upper mass limit of 3M J still holds. If the orbits are aligned, our model predicts M pl = 0.5M J, a pl = 115 AU, and e pl = 0.12. Parent bodies are evacuated from mean-motion resonances with Fom b; these empty resonances are akin to the Kirkwood gaps opened by Jupiter. The belt contains at least 3M ? of solids that are grinding down to dust, their velocity dispersions stirred so strongly by Fom b that collisions are destructive. Such a large mass in solids is consistent with Fom b having formed in situ.

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

2009-03-01

128

Astrometric Masses of Extrasolar Planets and Brown Dwarfs  

NASA Astrophysics Data System (ADS)

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

Benedict, George

2005-07-01

129

Astrometric Masses of Extrasolar Planets and Brown Dwarfs  

NASA Astrophysics Data System (ADS)

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses.Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

Benedict, George

2006-07-01

130

Astrometric Masses of Extrasolar Planets and Brown Dwarfs  

NASA Astrophysics Data System (ADS)

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses.Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

Benedict, George

2005-07-01

131

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

SciTech Connect

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

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

2012-08-01

132

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

133

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

NASA Astrophysics Data System (ADS)

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

Lewis, Alexia; Quinn, T.

2012-01-01

134

PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS  

SciTech Connect

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

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

2009-07-10

135

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

136

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

137

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

138

Origin and Bulk Chemical Composition of the Galilean Satellites of Jupiter and the Inner Planets  

NASA Astrophysics Data System (ADS)

It is proposed that both the Galilean satellites and the inner planets formed by the same mechanism, namely by condensation and accumulation of grains within gas rings cast off from the equators of the contracting, turbulent proto-Jovian/solar clouds.

Prentice, A. J. R.

1999-03-01

139

Formation of Jupiter-like Planets around Solar-type Stars  

Microsoft Academic Search

The gas giant planets of our solar system are believed to have formed through a two step process. First, collisional accumulation of a swarm of planetesimals produces a ~ 10 M_oplus core of ice and rock. Second, this core accretes an envelope of hydrogen and helium gas through the hydrodynamic collapse of disk gas onto the growing protoplanet. A necessary

A. P. Boss

1995-01-01

140

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

ERIC Educational Resources Information Center

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

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

2012-01-01

141

An extrasolar planetary system with three Neptune-mass planets.  

PubMed

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

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

2006-05-18

142

Orbital Evolution and Migration of Extrasolar Planets  

NASA Astrophysics Data System (ADS)

Giant planets in circumstellar disks can migrate inward from their initial (formation) positions. Migration is caused by inward torques between the planet and the disk; by outward torques between the planet and the spinning star; and by outward torques due to Roche lobe overflow and mass loss from the planet. Summing torques on planets in disks with various physical parameters, we find that Jupiter-mass planets can stably arrive and survive at small heliocentric distances. Inward migration timescales can be approximately equal to or less than disk lifetimes and star spindown timescales. Therefore, the range of fates of Jupiter-mass planets is broad, and generally comprises three classes: (I) planets which migrate inward too rapidly and lose all their mass due to Roche lobe overflow; (II) planets which migrate inward and survive in very small orbits; and (III) planets which do not migrate very far. Some, but not all, of the planets in Class II lose mass during their evolution and migration times, resulting in planets with final masses smaller than their initial masses. For example, in our model, we produce planets similar to 51 Peg b which have lost ~ 75% of their initial mass. The observed extrasolar planets, both those with extremely small semi-major axes (51 Peg b at 0.05 AU, tau Boo b (0.046 AU), upsilon And b (0.057 AU), and 55 Cnc b (0.11 AU)) and those with more moderate semi-major axes (rho Cor Bor b (0.23 AU), 47 UMa b (2.1 AU)) form a subset of the potential outcomes of the system, in that Jupiter-mass objects can stably survive in orbits with a wide range of semi-major axes. Our numerical model produces planets which have similar characteristics to the observed planets, as well as planets similar to Jupiter, and many intermediate cases. Since Jupiters can stably migrate to various orbital separations, we predict that, as planetary detection techniques improve, Jupiter-mass planets will be found in a wide range of orbits, from much less than 1 AU to several AU or more.

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

1997-07-01

143

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

144

[Extrasolar terrestrial planets and possibility of extraterrestrial life].  

PubMed

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

Ida, Shigeru

2003-12-01

145

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

146

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

147

Estimating the masses of extra-solar planets  

NASA Astrophysics Data System (ADS)

All extra-solar planet masses that have been derived spectroscopically are lower limits since the inclination of the orbit to our line-of-sight is unknown except for transiting systems. In theory, however, it is possible to determine the inclination angle, i, between the rotation axis of a star and an observer's line-of-sight from measurements of the projected equatorial velocity (vsini), the stellar rotation period (Prot) and the stellar radius (R*). For stars which host planetary systems this allows the removal of the sini dependency of extra-solar planet masses derived from spectroscopic observations under the assumption that the planetary orbits lie perpendicular to the stellar rotation axis. We have carried out an extensive literature search and present a catalogue of vsini,Prot and R* estimates for stars hosting extra-solar planets. In addition, we have used Hipparcos parallaxes and the Barnes-Evans relationship to further supplement the R* estimates obtained from the literature. Using this catalogue, we have obtained sini estimates using a Markov-chain Monte Carlo analysis. This technique allows proper 1? two-tailed confidence limits to be placed on the derived sini's along with the transit probability for each planet to be determined. While we find that a small proportion of systems yield sini's significantly greater than 1, most likely due to poor Prot estimations, the large majority are acceptable. We are further encouraged by the cases where we have data on transiting systems, as the technique indicates inclinations of ~90° and high transit probabilities. In total, we are able to estimate the true masses of 133 extra-solar planets. Of these 133 extra-solar planets, only six have revised masses that place them above the 13MJ deuterium burning limit; four of those six extra-solar planet candidates were already suspected to lie above the deuterium burning limit before correcting their masses for the sini dependency. Our work reveals a population of high-mass extra-solar planets with low eccentricities, and we speculate that these extra-solar planets may represent the signature of different planetary formation mechanisms at work. Finally, we discuss future observations that should improve the robustness of this technique.

Watson, C. A.; Littlefair, S. P.; Collier Cameron, A.; Dhillon, V. S.; Simpson, E. K.

2010-11-01

148

Terrestrial planets in high-mass disks without gas giants  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

149

Low-mass planets in nearly inviscid disks: numerical treatment  

NASA Astrophysics Data System (ADS)

Context. Embedded planets disturb the density structure of the ambient disk, and gravitational back-reaction possibly will induce a change in the planet's orbital elements. Low-mass planets only have a weak impact on the disk, so their wake's torque can be treated in linear theory. Larger planets will begin to open up a gap in the disk through nonlinear interaction. Accurate determination of the forces acting on the planet requires careful numerical analysis. Recently, the validity of the often used fast orbital advection algorithm (FARGO) has been put into question, and special numerical resolution and stability requirements have been suggested. Aims: We study the process of planet-disk interaction for low-mass planets of a few Earth masses, and reanalyze the numerical requirements to obtain converged and stable results. One focus lies on the applicability of the FARGO-algorithm. Additionally, we study the difference of two and three-dimensional simulations, compare global with local setups, as well as isothermal and adiabatic conditions. Methods: We study the influence of the planet on the disk through two- and three-dimensional hydrodynamical simulations. To strengthen our conclusions we perform a detailed numerical comparison where several upwind and Riemann-solver based codes are used with and without the FARGO-algorithm. Results: With respect to the wake structure and the torque density acting on the planet, we demonstrate that the FARGO-algorithm yields correct a correct and stable evolution for the planet-disk problem, and that at a fraction of the regular cpu-time. We find that the resolution requirements for achieving convergent results in unshocked regions are rather modest and depend on the pressure scale height H of the disk. By comparing the torque densities of two- and three-dimensional simulations we show that a suitable vertical averaging procedure for the force gives an excellent agreement between the two. We show that isothermal and adiabatic runs can differ considerably, even for adiabatic indices very close to unity.

Kley, W.; Müller, T. W. A.; Kolb, S. M.; Benítez-Llambay, P.; Masset, F.

2012-10-01

150

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

SciTech Connect

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

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

2011-06-11

151

Planet Formation around Stars of Various Masses: The Snow Line and the Frequency of Giant Planets  

NASA Astrophysics Data System (ADS)

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

Kennedy, Grant M.; Kenyon, Scott J.

2008-01-01

152

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

SciTech Connect

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

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

2011-01-20

153

Terrestrial Planet Formation During the Migration and Resonance Crossings of the Giant Planets  

NASA Astrophysics Data System (ADS)

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

Lykawka, Patryk S.; Ito, T.

2013-10-01

154

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

Microsoft Academic Search

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

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

2006-01-01

155

Atmospheres From Very Low-Mass Stars to Extrasolar Planets  

NASA Astrophysics Data System (ADS)

Within the next few years, several instruments aiming at imaging extrasolar planets will see first light. In parallel, low mass planets are being searched around red dwarfs which offer more favorable conditions - both for radial velocity detection and transit studies - than solar-type stars. We review recent advancements in modeling the stellar to substellar transition. The revised solar oxygen abundances and cloud models allow to reproduce the photometric and spectroscopic properties of this transition to a degree never achieved before, but problems remain at the stellar-brown dwarf transition typical of the Teff range of characterizable exoplanets.

Allard, F.; Homeier, D.; Freytag, B.; Sharp, C. M.

2012-11-01

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

The use of transit timing to detect terrestrial-mass extrasolar planets.  

PubMed

Future surveys for transiting extrasolar planets are expected to detect hundreds of jovian-mass planets and tens of terrestrial-mass planets. For many of these newly discovered planets, the intervals between successive transits will be measured with an accuracy of 0.1 to 100 minutes. We show that these timing measurements will allow for the detection of additional planets in the system (not necessarily transiting) by their gravitational interaction with the transiting planet. The transit-time variations depend on the mass of the additional planet, and in some cases terrestrial-mass planets will produce a measurable effect. In systems where two planets are seen to transit, the density of both planets can be determined without radial-velocity observations. PMID:15731449

Holman, Matthew J; Murray, Norman W

2005-02-25

158

The Orbits of the Regular Jovian Satellites, Their Masses, and the Gravity Field of Jupiter  

NASA Astrophysics Data System (ADS)

Abstract (2,250 Maximum Characters): At the end of the Galileo mission, we produced ephemerides for the Galilean and inner Jovian satellites based on numerical integrations of their orbits fit to a variety of Earth-based and spacecraft observations. A necessary byproduct of this effort was improved knowledge of the satellite masses and Jupiter's gravity field. The Earth-based observation set spanned the years 1967---2001 and included: Earth-based astrometry, satellite mutual eclipses and occultations, and satellite eclipses by Jupiter. The spacecraft observations included: Doppler tracking, radiometric range, very-long baseline interferometry, and optical navigation imaging from Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Ulysses, Galileo, Cassini. To support the Juno mission, currently enroute to Jupiter, we have begun an update of the satellite ephemerides. We are reprocessing all of the observations used in our earlier analysis but with improved software and procedures developed in recent years to support the Cassini mission at Saturn. Moreover, we have extended the Earth-based astrometry back to 1891 and forward to 2012 and have expanded the set of mutual eclipses and occultations to include those obtained in 1997, 2002/2003, and 2009. We have also added the imaging observations made by the New Horizons spacecraft during its 2007 flyby of Jupiter. In this paper we report on the status of our ephemeris update and compare our current results with those obtained at the end of the Galileo mission.

Jacobson, Robert A.

2013-05-01

159

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

NASA Astrophysics Data System (ADS)

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

Hasegawa, Yasuhiro; Hirashita, Hiroyuki

2014-06-01

160

Jupiter’s moment of inertia: A possible determination by Juno  

Microsoft Academic Search

The moment of inertia of a giant planet reveals important information about the planet’s internal density structure and this information is not identical to that contained in the gravitational moments. The forthcoming Juno mission to Jupiter might determine Jupiter’s normalized moment of inertia NMoI=C\\/MR2 by measuring Jupiter’s pole precession and the Lense–Thirring acceleration of the spacecraft (C is the axial

Ravit Helled; John D. Anderson; Gerald Schubert; David J. Stevenson

2011-01-01

161

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

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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.

170

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

SciTech Connect

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

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

2013-08-10

171

WASP12b as a prolate, inflated and disrupting planet from tidal dissipation  

Microsoft Academic Search

The class of exotic Jupiter-mass planets that orbit very close to their parent stars were not explicitly expected before their discovery. The recently discovered transiting planet WASP-12b has a mass M = 1.4+\\/-0.1 Jupiter masses (MJ), a mean orbital distance of only 3.1 stellar radii (meaning it is subject to intense tidal forces), and a period of 1.1days. Its radius

Shu-Lin Li; Neil Miller; Douglas N. C. Lin; Jonathan J. Fortney

2010-01-01

172

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

PubMed

The composition of the jovian atmosphere from 0.5 to 21 bars along the descent trajectory was determined by a quadrupole mass spectrometer on the Galileo probe. The mixing ratio of He (helium) to H2 (hydrogen), 0.156, is close to the solar ratio. The abundances of methane, water, argon, neon, and hydrogen sulfide were measured; krypton and xenon were detected. As measured in the jovian atmosphere, the amount of carbon is 2.9 times the solar abundance relative to H2, the amount of sulfur is greater than the solar abundance, and the amount of oxygen is much less than the solar abundance. The neon abundance compared with that of hydrogen is about an order of magnitude less than the solar abundance. Isotopic ratios of carbon and the noble gases are consistent with solar values. The measured ratio of deuterium to hydrogen (D/H) of (5 +/- 2) x 10(-5) indicates that this ratio is greater in solar-system hydrogen than in local interstellar hydrogen, and the 3He/4He ratio of (1.1 +/- 0.2) x 10(-4) provides a new value for protosolar (solar nebula) helium isotopes. Together, the D/H and 3He/4He ratios are consistent with conversion in the sun of protosolar deuterium to present-day 3He. PMID:8629016

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

1996-05-10

173

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

174

Juno: Launching to Jupiter  

NASA Video Gallery

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

175

Discovery of a Jupiter/Saturn analog with gravitational microlensing.  

PubMed

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

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

2008-02-15

176

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

177

Jupiter: friend or foe?  

NASA Astrophysics Data System (ADS)

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

Horner, Jonti; Jones, Barrie W.

2008-02-01

178

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

179

On the Minimum Core Mass for Giant Planet Formation  

NASA Astrophysics Data System (ADS)

In the core accretion hypothesis, giant planets form by accreting gas from the protoplanetary disk onto a solid core. Ten Earth masses (10 M_E) is often quoted as the minimum or critical core mass required to form a gas giant. However, the critical core mass can vary greatly depending on various quantities, including: the location in and conditions of the disk, the atmospheric composition and opacity (which may differ from the disk) and the accretion rate of planetesimals or smaller solids. To investigate these issues, we consider the growth of atmospheres in the limiting case of a fixed core mass with no ongoing accretion of solids. We thus obtain absolute lower limits on the critical core mass because additional heat sources limit the ability of the atmosphere to cool and undergo Kelvin-Helmholtz contraction. To study this contraction over a wide range of parameter space, we develop a simplified two-layer cooling model. The model's main approximation is that atmospheric luminosity is primarily generated in the convective interior, so that the luminosity generated in the radiative exterior can be neglected. We focus our attention on the outer region of protoplanetary disks, where our approximations are more valid, and where direct imaging searches are finding giant planets that constrain formation models. To form a gas giant, we require that runaway gas growth occurs within 3 Myr, a characteristic disk lifetime, though the time to grow the core (in situ or otherwise) is not included. Our main finding is that the critical core mass declines with distance in the disk. For our standard model, the critical core mass drops from 8.5 M_E at 5 AU to 3.5 M_E at 100 AU. This result arises primarily from lower disk temperatures. A lower disk density or pressure (at fixed temperature) only modestly increases critical core masses. Lowering the opacity also gives lower critical core masses. We also develop a simplified analytic cooling model, which explains the basic trends and shows that atmospheric self-gravity plays a crucial role in atmospheric growth -- even when the atmosphere is less massive than the core.

Youdin, Andrew; Piso, A.

2013-10-01

180

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

181

Jupiter and Saturn  

Microsoft Academic Search

Jupiter, the largest planet, and Saturn, the second largest, contain nine-tenths of the material of the solar system outside the Sun and most of the angular momentum of the solar system is associated with their orbital motion. Both planets rotate very rapidly (rotation periods ~ 10 h) and possess rich satellite systems. Owing to their strong gravitational fields and low

R. Hide

1974-01-01

182

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

SciTech Connect

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

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

2010-04-01

183

Origin of Giant Planet Instabilities  

NASA Astrophysics Data System (ADS)

The observed eccentricity distribution of extrasolar giant planets has been successfully reproduced (e.g. Juric and Tremaine, 2008; Chatterjee et al., 2008) assuming that said planets formed in systems of at least three planets that became unstable. However, these works placed the planets initially on circular and non-resonant orbits that were too close to each other to be stable. In reality, giant planets form in disks of gas, and their orbits should be the result of migration and eccentricity-damping processes induced by their gravitational interaction with said disks. In this work we simulate the evolution of systems of three planets as they grow in sequence to Jupiter mass. We use the hydro-dynamical code FARGO (Masset, 2000) that we modified to implement the algorithm Symba (Duncan et al., 1998) to solve the gravitational interactions among the planets, handling also close-encounters and mutual collisions. We start our simulations with sets of three embryos of 20 Earth masses in resonant configuration. The growth of each embryo to Jupiter mass leads to a global instability, but the damping action of the gas eventually re-stabilizes the system into a new orbital configuration. However, once the three planets are all giants, their orbital eccentricities can grow to large values on short timescales through their mutual resonant interactions, while migrating towards the star. We study their subsequent evolution as a function of the disk mass and dissipation time. We conclude that the observed large eccentricities of many extrasolar planets are best reproduced if planets become giants towards the end of the disk lifetime, when the density of gas is rapidly decaying. Instead, if they form in massive disks, their orbital instabilities lead to systems with fewer planets and/or separated orbits with small eccentricities, due to the strong damping action of the disk, as in Marzari et al (2010).

Lega, Elena; Morbidelli, A.; Nesvorny, D.

2012-10-01

184

Magnetically Controlled Outflows from Hot Jupiters  

NASA Astrophysics Data System (ADS)

Recent observations indicate that some extrasolar planets observed in transit can experience mass loss from their surfaces. Motivated by these findings, this paper considers outflows from hot Jupiters in the regime where the flow is controlled by magnetic fields. Given the mass-loss rates estimated from current observations—and from theoretical arguments—magnetic fields will dominate the flow provided that field strength near the planet is greater than ~1 G, comparable to the surface fields of the Sun and Jupiter. The problem can be separated into an inner regime, near the planet, where the outflow is launched, and an outer regime where the flow follows (primarily) stellar field lines and interacts with the stellar wind. This paper concentrates on the flow in the inner regime. For a dipole planetary field with a spatially constant background contribution, we construct a set of orthogonal coordinates that follow the field lines and determine the corresponding differential operators. Under the assumption of isothermal flow, we analytically find the conditions required for escaping material to pass smoothly through the sonic transition and then estimate the mass outflow rates. These magnetically controlled outflows differ significantly from previous spherical models. The outflow rates are somewhat smaller, typically {\\dot{M}} ~109 g s-1, and the flow is launched primarily from the polar regions of the planet. In addition, if the stellar wind is strong enough, the flow could be reversed and the planet could gain mass from the star.

Adams, Fred C.

2011-03-01

185

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

186

Transforming Gas Giant Planets into Smaller Objects Through Tidal Disruption  

NASA Astrophysics Data System (ADS)

Recent observations have revealed several Jupiter-mass planets with highly eccentric and / or misaligned orbits, which clearly suggests that dynamical processes operated in these systems. These dynamical processes may result in close encounters between Jupiter-like planets and their host stars. Using three-dimensional hydrodynamical simulations, we find that planets with cores are more likely to be retained by their host stars in contrast with previous studies which suggested that coreless planets are often ejected. We propose that after a long term evolution some gas giant planets could be transformed into super-Earths or Neptune-like planets, which is supported by our adiabatic evolution models. Finally, we analyze the orbits and structure of known planets and Kepler candidates and find that our model is capable of producing some of the shortest-period objects.

Liu, Shang-Fei; Guillochon, James; Lin, Douglas N. C.; Ramirez-Ruiz, Enrico

2014-04-01

187

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

188

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

SciTech Connect

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

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

2010-03-10

189

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

190

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

191

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

192

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

193

Horseshoe periodic orbits in the restricted problem of three bodies for a sun-Jupiter mass ratio  

Microsoft Academic Search

Segments of seven families of symmetric horseshoe periodic orbits of the restricted three body problem for a sun-Jupiter mass ratio have been numerically determined. Each family is found to have a region consisting of smooth horseshoe shaped orbits with the family evolving to orbits acquiring loops on both sides of the smooth horseshoes. The general evolution of these families is

D. B. Taylor

1981-01-01

194

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.

195

The Planet-B neutral gas mass spectrometer  

NASA Astrophysics Data System (ADS)

The Planet-B neutral gas mass spectrometer is designed for in-situ measurements of the gas composition in the upper atmosphere of Mars. The sensor uses a dual frequency quadrupole mass analyzer with a mass range of 1-60amu (atomic mass units) and two electron multipliers to cover the dynamic range required. The ion source, which is collinear with the analyzer, operates in two different modes: 1) a closed source mode measuring non-surface reactive neutral species that have thermally accommodated to the gas inlet walls; and 2) an open source mode measuring chemically surface active species by direct beaming with no surface collisions. The in-line Retarding Potential Analysis (RPA) system selects the mode of operation. An onboard Field Programmable Gate Array (FPGA) is used to control the instrument operating parameters in accordance with pre-programmed sequences and to package the telemetry data. The sensor is sealed and maintained in a vacuum prior to launch and will be opened to the environment of Mars after orbit insertion. Measurements of He, N, O, CO, N2, NO, O2, Ar, and CO2 will be done at periapsis and the data will be used to determine the variation of the neutral atmosphere density and temperature with altitude, local solar time and season. Measurements are possible from 130-140km to 500km depending on the gas species, chemical background, and instrument measurement mode. The data will contribute to the studies of thermosphere energetics, lower atmosphere meteorology (e.g. dust storms) and serve as a resource for studies of the interaction of the upper atmosphere with the solar wind.

Niemann, H. B.; Harpold, D. N.; Feng, S.; Kasprzak, W. T.; Way, S. H.; Atreya, S. K.; Block, B.; Carignan, G. R.; Donahue, T. M.; Nagy, A. F.; Bougher, S. W.; Hunten, D. M.; Owen, T. C.; Bauer, S. J.; Hayakawa, H. J.; Mukai, T.; Miura, Y. N.; Sugiura, N.

1998-09-01

196

Two Jovian-Mass Planets in Earthlike Orbits  

Microsoft Academic Search

We report the discovery of two new planets: a 1.94 MJup planet in a 1.8 yr orbit of HD 5319, and a 2.51 MJup planet in a 1.1 yr orbit of HD 75898. The measured eccentricities are 0.12 for HD 5319b and 0.10 for HD 75898b, and Markov chain Monte Carlo simulations based on the derived orbital parameters indicate that

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

2007-01-01

197

The Gemini Planet Imager  

NASA Astrophysics Data System (ADS)

The Gemini Planet Imager (GPI) is a next-generation adaptive optics coronagraph designed for direct imaging and spectroscopy of extrasolar planets and polarimetry of circumstellar disks. It is the first such facility-class instrument deployed on a 8-m telescope, designed to achieve contrast levels of up to 10^7. This allows observations of warm self-luminous planets, with masses greater than a Jupiter mass and ages less than a few hundred megayears. GPI will be used for a large-scale survey of 600 nearby young stars, as well as for guest observer science. I will present first-light science results and discuss the scientific capabilities of GPI.

Macintosh, Bruce

2014-06-01

198

Possible Collisions of P/Halley and P/Machholz 1 with Jupiter and the Terrestrial Planets  

NASA Astrophysics Data System (ADS)

The perturbed motion of comet Halley and comet Mackholz 1 1986 VIII was investigated within a time interval of about 20 millennia. The minimal distance of 0.043 AU between P/Halley and Venus may occur on April 4, 4868 AD. The distance of 0.036 AU between P/Halley and Jupiter will take place on April 1, 6616 AD. The orbit of P/Machholz 1 crosses the orbits of Mercury and Venus eight times, that of the Earth six or eight times, and the orbit of Mars four times per a period of advance of the argument of perihelion. A distance of about 0.06 AU between P/Machholz 1 and the Earth may take place in August 2576 AD and 5751 AD and in February 4770 AD. The minimal comet-Earth distance of 0.035 AU occurs on September 14, 5971 AD. The closest encounter between P/Machholz 1 and Jupiter at the distance of 0.098 AU may be in May 4499 AD. These results may be considered as a forecast of possible collisions.

Obrubov, Yu. V.

1996-02-01

199

Jupiter: Earth's Shield  

NSDL National Science Digital Library

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

2011-02-01

200

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

201

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

202

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

203

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

204

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

205

Catastrophic Collisions in the Terrestrial Planet Zone and the Epoch of Terrestrial Planet Formation around Intermediate Mass Stars  

NASA Astrophysics Data System (ADS)

We have completed an extensive search for stars hosting terrestrial planet zone dust by cross-correlating the Tycho-2 and IRAS catalogs. Near-infrared to far-infrared excess emission has been discovered towards a 10-20 Myr old, A-type member of the Upper-Centaurus-Lupus association. The hot dust component ( 750 K) in combination with the high fractional infrared luminosity (0.4%) suggest a recent catastrophic collision between rocky bodies in this intermediate mass star's inner planetary system. Synthesis of all published incidences of intermediate mass stars with evidence for terrestrial planet zone dust suggests that catastrophic collisions analogous to the Moon-forming event in our Solar System occur around intermediate mass stars when the star is 10-30 Myr old. Funding for this research came from NASA grants and an LLNL-Minigrant to UCLA and from the Spitzer Visiting Graduate Student Program.

Melis, Carl; Zuckerman, B.; Song, I.; Rhee, J. H.; Bessell, M. S.; Murphy, S. J.

2010-01-01

206

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

207

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

208

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

PubMed

The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe. PMID:11541457

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

1998-01-01

209

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.

210

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

211

Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System  

NASA Astrophysics Data System (ADS)

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 ~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 ? planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 ± 0.044 R ?, 1.528 ± 0.087 M ?) and M dwarf (0.378 ± 0.023 R ?, 0.408 ± 0.024 M ?). For the planet, we find an upper mass limit of 169 M ? (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 ~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.; Orosz, Jerome A.; Carter, Joshua A.; Welsh, William F.; Fischer, Debra A.; Torres, Guillermo; Howard, Andrew W.; Crepp, Justin R.; Keel, William C.; Lintott, Chris J.; Kaib, Nathan A.; Terrell, Dirk; Gagliano, Robert; Jek, Kian J.; Parrish, Michael; Smith, Arfon M.; Lynn, Stuart; Simpson, Robert J.; Giguere, Matthew J.; Schawinski, Kevin

2013-05-01

212

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

213

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

214

The First Extrasolar Planet Discovered with A New Generation High Throughput Doppler Instrument  

Microsoft Academic Search

We report the first extrasolar planet, ET1, detected with a new generation Doppler instrument, called Exoplanet Tracker. This planet has a minimum mass of 0.41 Jupiter masses and orbits a V = 8.1 K0V star with a 4.8 day period. The planet was identified using the KPNO Coude Feed 0.9 meter telescope in spring 2005. This is the first time

J. Ge; J. van Eyken; S. Mahadevan; C. DeWitt; R. Cohen; A. Vanden Heuvel; S. Fleming; P. Guo; S. Kane; G. Henry; G. Israelian; E. Martin

2005-01-01

215

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

216

The f(alpha) singularity spectrum of the planets in the solar system  

Microsoft Academic Search

The set of planets in the solar system consists of the nine objects Pluto up to and including Jupiter, in increasing order of planet size and mass. We have stimulating numerical evidence that this set can be approximated by a two-scale Cantor multi-fractal with l1≈0.40 and p1≈0.15.

Will H. Siekman

2001-01-01

217

Reevaluating the Feasibility of Ground-based Earth-mass Microlensing Planet Detections  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

218

Giant collisions involving young Jupiter  

Microsoft Academic Search

We present high-resolution, three-dimensional simulations using a smooth particle hydrodynamics (SPH) code of giant impacts involving young Jupiter-like planets. Our aim is to explore the effect of such impacts on the structure and evolution of the planet and discuss the likelihood of detecting these post-impact planets. For this, we considered head-on and off-axis impacts by an Earth-like planet onto a

A. Anic; Y. Alibert; W. Benz

2007-01-01

219

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

220

The Pull of the Planets  

NSDL National Science Digital Library

Learners will model the gravitational fields of planets on a flexible surface. Children place and move balls of different sizes and densities on a plastic sheet to develop a mental picture of how the mass of an object influences how much effect it has on the surrounding space. This activity is part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

221

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

NASA Astrophysics Data System (ADS)

We have a plan to conduct a Doppler planet search for low-mass planets around nearby middle-to-late M dwarfs using IRD. IRD is the near-infrared high-precision radial velocity instrument for the Subaru 8.2-m telescope. We expect to achieve the accuracy of the radial velocity measurements of 1 m/s using IRD with a frequency comb as a wavelengh calibrator. Thus, we would detect super-Earths in habitable zone and low-mass rocky planets in close-in orbits around late-M dwarfs. In this survey, we aim to understand and discuss statistical properties of low-mass planets around low-mass M dwarfs compared with those derived from theoretical simulations.

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

2014-04-01

222

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

223

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

224

Magnetically Controlled Outflows from Hot Jupiters  

NASA Astrophysics Data System (ADS)

Recent observations that indicate that some extrasolar planets observed in transit can experience mass loss from their surfaces. Motivated by these findings, we consider outflows from Hot Jupiters in the regime where the flow is controlled by magnetic fields. Given the mass loss rates estimated from current observations (and from theory) magnetic fields will dominate the flow for planets with surface fields greater than 1 gauss, comparable to the fields of the Sun and Jupiter. More specifically, the magnetic pressure is larger than the ram pressure of the wind by a factor of 1,000,000 at the planet surface and a factor of 10,000 at the sonic surface. The problem can be separated into an inner regime, near the planet, where the outflow is launched, and an outer regime where the flow follows (primarily) stellar field lines and interacts with the stellar wind. We consider a variety of field configurations, but start with a dipole planetary field with a spatially constant background contribution from the star. For each field configuration, we construct a set of orthogonal coordinates that follow the field lines and determine the corresponding differential operators. Under the assumption of polytropic flow, we can analytically find the conditions required for escaping material to pass smoothly through the sonic transition, and can then estimate the mass outflow rates. These magnetically controlled outflows differ significantly from previous spherical models: The outflow rates are somewhat smaller, and the flow is launched primarily from the polar regions of the planet. In addition, if the stellar wind is strong enough, the flow could be reversed and the planet could gain mass from the star; this latter scenario may operate in the earliest (and hence most extreme) stages of evolution.

Adams, Fred C.

2011-09-01

225

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

SciTech Connect

Compared to the giant planets in the solar system, exoplanets have many remarkable properties, such as the prevalence of giant planets on eccentric orbits and the presence of hot Jupiters. Planet-planet scattering (PPS) between giant planets is a possible mechanism to interpret the above and other observed properties. If the observed giant planet architectures are indeed outcomes of PPS, such a drastic dynamical process must affect their primordial moon systems. In this Letter, we discuss the effect of PPS on the survival of exoplanets' regular moons. From an observational viewpoint, some preliminary conclusions are drawn from the simulations. (1) PPS is a destructive process to the moon systems; single planets on eccentric orbits are not ideal moon-search targets. (2) If hot Jupiters formed through PPS, their original moons have little chance of survival. (3) Planets in multiple systems with small eccentricities are more likely to hold their primordial moons. (4) Compared with lower-mass planets, massive planets in multiple systems may not be the preferred moon-search targets if the system underwent a PPS history.

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

2013-05-20

226

Jupiter Formed with More Tar than Ice  

NASA Astrophysics Data System (ADS)

Elemental abundances in Jupiter determined from Galileo probe measurements are compared to recently revised solar system abundances. When normalized to the abundance of sulfur, the most abundant refractory rock-forming element reliably determined in Jupiter's atmosphere by the Galileo probe, abundances of argon, krypton, and xenon are 1 times solar, the observed oxygen is depleted by a factor of 4, and carbon is enriched 1.7 times. The fairly uncertain nitrogen abundance ranges from 1 to 3 times solar. The oxygen abundance in Jupiter derived from the observed atmospheric water abundance is only a lower limit to the total planetary oxygen because oxygen is also bound to rock-forming elements such as magnesium or silicon sequestered deep in the planet. The sulfur abundance constrains the amount of rock-forming elements on Jupiter. Considering the amount of oxygen bound to silicate rock, the total oxygen abundance on Jupiter of 0.47 times solar system indicates an overall oxygen depletion by about a factor of 2. The hydrogen and helium abundances in the Jovian atmosphere are depleted (0.48 and 0.39 times solar system, respectively). These relative depletions may indicate the extent of hydrogen and helium partitioning from the molecular envelope into Jupiter's metallic layer. A formation scenario for Jupiter is proposed to explain the relative oxygen depletion and, at the same time, the relative carbon enrichment. In essence, the model assumes that at the time of Jupiter's formation, abundant carbonaceous matter was present near 5.2 AU rather than abundant water ice, increasing the surface mass density of solids in the solar nebula accretion disk. Carbonaceous matter, which has high sticking probabilities, was the agent that sped up accumulation of solid matter of proto-Jupiter. This led to runaway accretion of the planet. Major consequences of this scenario are that the water ice condensation front (the snow line) typically placed near 5.2 AU in solar nebula models must be replaced by a carbonaceous condensation/evaporation front (the ``tar line'') and that the snow line is located farther out in the solar nebula.

Lodders, Katharina

2004-08-01

227

Influence of Giant Planets near the 5:2 Resonance in the Habitable Zone of Sun-Like Stars  

NASA Astrophysics Data System (ADS)

From the nearly 190 planets that have been discovered so far we can distinguish the following types of HZs from the dynamicals point of view: 1) The solar-system type (SST) - where the HZ is between the host-star and the detected giant planet. 2) The hot-Jupiter type (HJT) for a close-in giant planet, the HZ is outside its orbit. 3) The giant planet type (GPT) - when the detected planet moves in the HZ. In this case we can only expect "habitable moons" or "habitable trojan-like planets". 4) Furthermore in multi-planet systems there will be combinations of these 3 types. But even if a planet will be detected in the HZ, it has to be verified if it can be considered as habitable planet. An important contribution from the dynamical point of view is to examine the long-term dynamical behavior of the orbital motion in this region, which obviously depends on the motion of the giant planets in the systems. Motivated by the fact, that in some of the discovered multi-planet systems the giant planets move in mean motion resonance, we studied the influence of giant planets, that are close to the 5:2 mean motion resonance on the habitable zone of a sun-like star. Starting with the actual Jupiter-Saturn-Uranus configuration of our Solar-System one can see how the perturbation changes when we increase Saturn's mass (from 1 to 9 Jupiter-masses).

Pilat-Lohinger, E.; Suli, A.; Freistetter, F.; Dvorak, R.; Schwarz, R.; Funk, B.

228

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

SciTech Connect

The torques exerted by a locally isothermal disk on an embedded planet lead to rapid inward migration. Recent work has shown that modeling the thermodynamics without the assumption of local isothermality reveals regions where the net torque on an embedded planet is positive, leading to outward migration of the planet. When a region with negative torque lies directly exterior to this, planets in the inner region migrate outward and planets in the outer region migrate inward, converging where the torque is zero. We incorporate the torques from an evolving non-isothermal disk into an N-body simulation to examine the behavior of planets or planetary embryos interacting in the convergence zone. We find that mutual interactions do not eject objects from the convergence zone. Small numbers of objects in a laminar disk settle into near resonant orbits that remain stable over the 10 Myr periods that we examine. However, either or both increasing the number of planets or including a correlated, stochastic force to represent turbulence drives orbit crossings and mergers in the convergence zone. These processes can build gas giant cores with masses of order 10 Earth masses from sub-Earth mass embryos in 2-3 Myr.

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

2012-05-01

229

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

SciTech Connect

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

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

2011-04-01

230

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.

231

Direct imaging of multiple planets orbiting the star HR 8799.  

PubMed

Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step toward imaging Earth-like planets. Imaging detections are challenging because of the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our solar system. PMID:19008415

Marois, Christian; Macintosh, Bruce; Barman, Travis; Zuckerman, B; Song, Inseok; Patience, Jennifer; Lafrenière, David; Doyon, René

2008-11-28

232

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

233

Cold Hole Over Jupiter's Pole  

NASA Technical Reports Server (NTRS)

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

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

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

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

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

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

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

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

2002-01-01

234

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

235

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

236

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.

237

Eccentricity Evolution of Migrating Planets  

NASA Technical Reports Server (NTRS)

We examine the eccentricity evolution of a system of two planets locked in a mean motion resonance, in which either the outer or both planets lose energy and angular momentum. The sink of energy and angular momentum could be a gas or planetesimal disk. We analytically calculate the eccentricity damping rate in the case of a single planet migrating through a planetesimal disk. When the planetesimal disk is cold (the average eccentricity is much less than 1), the circularization time is comparable to the inward migration time, as previous calculations have found for the case of a gas disk. If the planetesimal disk is hot, the migration time can be an order of magnitude shorter. We show that the eccentricity of both planetary bodies can grow to large values, particularly if the inner body does not directly exchange energy or angular momentum with the disk. We present the results of numerical integrations of two migrating resonant planets showing rapid growth of eccentricity. We also present integrations in which a Jupiter-mass planet is forced to migrate inward through a system of 5-10 roughly Earth-mass planets. The migrating planets can eject or accrete the smaller bodies; roughly 5% of the mass (averaged over all the integrations) accretes onto the central star. The results are discussed in the context of the currently known extrasolar planetary systems.

Murray, N.; Paskowitz, M.; Holman, M.

2002-01-01

238

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.

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

2000-01-01

239

Extremely Inflated Hot Jupiters Could Be Extremely Young  

NASA Astrophysics Data System (ADS)

Extremely inflated hot Jupiters could have formed recently from the merger of two low-mass stars. The frequency of W UMa stars is not enough to account for many inflated hot Jupiters, so low mass detached binaries could also contribute to the progenitor population. We find that the degree of inflation of the transiting hot Jupiters correlates with their expected spiral-in life time by tidal dissipation, and this could be an indication of youth if the Q dissipation parameter is sufficiently low, as suggested by the studies of the Jupiter-Io system. There is also a correlation between radius anomaly and host star rotational velocity as expected in the merger scenario. The distribution of rotational velocities among the host stars is statistically similar to that of blue stragglers in the globular cluster 47 Tuc. A significant challenge to the binary merger hypothesis is the efficient angular momentum loss required to explain the slow rotation of some inflated hot Jupiter host stars. As observational tests we point out that if hot Jupiters are mainly formed as a result of binary mergers, the frequency of this kind of planets should be higher around blue stragglers than around T Tauri stars. The presenter is supported by funding from the Spanish Ministry of Science and Technology and the ROPACS european training network.

Martin, Eduardo L.; Spruit, Henk; Tata, Ramarao

2011-09-01

240

Detecting Planets in the Galactic Bulge  

NASA Astrophysics Data System (ADS)

Determination of the frequency of planets in environments different from the local neighborhood, such as the Galactic bulge, may provide clues to the origin of planets. There are three currently feasible methods of detecting planetary companions to stars in the bulge: gravitational microlensing, transit, and "direct" detection. Microlensing searches for planets have been ongoing for six years, and have yielded interesting constraints on the frequency of Jupiter-mass planets around typical stars in the bulge (M-dwarfs) with separations 1 AU ? a ? 5 AU. If continued, such searches should eventually result in detections. Detecting bulge planets via transits requires a campaign of least 10 nights on a 10m-class telescope at an excellent site. Such a campaign would detect 5-50 Jupiter-size planets with a? 0.1 AU, if the frequency of planets in the bulge is similar to that locally. As a consistency check, close-in giant planetary companions can also be "directly" detected in caustic crossing binary-lens events, where the reflected light of the planet can be magnified by two orders of magnitude. Direct detection requires a few hours of intensive monitoring per binary-lens microlensing light curve using a 10m-class telescope. Combining these methods may eventually yield a complete census of Jovian companions to stars in the bulge with separations 0.01-10 AU. With a larger investment in observing resources, this range could plausibly be extended to ? 20 AU.

Gaudi, B. S.

2000-12-01

241

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

242

Evaporation of extrasolar planets  

Microsoft Academic Search

This article presents a review on the observations and theoretical modeling of the evaporation of extrasolar planets. The observations and the resulting constraints on the upper atmosphere (thermosphere and exosphere) of the ``hot-Jupiters'' are described. The early observations of the first discovered transiting extrasolar planet, HD209458b, allowed the discovery that this planet has an extended atmosphere of escaping hydrogen. Subsequent

A. Lecavelier Des Etangs

2010-01-01

243

An estimation of the mass of asteroid 20-Massalia derived from the HIPPARCOS minor planets data  

Microsoft Academic Search

The ESA astrometry satellite Hipparcos has observed a set of 48 minor planets between 1989 and 1993. A close encounter between 20-Massalia and 44-Nysa, both planets observed by Hipparcos, enabled us to obtain a value for the mass of 20-Massalia. Due to another close approach with the large asteroid 4-Vesta, the value we obtained (2.42 +\\/- 0.41 10(-12) Msun) is

Jeff Bange

1998-01-01

244

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

Microsoft Academic Search

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

Alexander Wolszczan

1994-01-01

245

The EXPLORE Project: A Microlensing Search for Free-Floating Terrestrial-Mass Planets  

Microsoft Academic Search

We describe and present preliminary results from our microlensing search for free-floating terrestrial-mass extrasolar planets. Using the MOSAIC II 36'x36' wide-field imager on the CTIO 4m telescope for 11 nights (6 clear) in June 2001, we followed a single field near the galactic plane (as part of an ongoing planet transit search). We monitored ~300,000 stars with I < 20,

S. Seager; G. Mallen-Ornelas; D. Minniti; H. K. C. Yee; M. D. Gladders; G. M. Mallen

2001-01-01

246

CoRoT-Exo-7b: Confirming the first transiting rocky planet  

Microsoft Academic Search

Earlier this month CoRoT announced the discovery of a periodic photometric signal compatible with a 1.76 REarth planet transiting a bright (V=11.7, K=9.8) K0V star. If confirmed, this planet would mark the beginning of a new era in exoplanetary science. Unlike Hot Jupiters, low mass planets may have a much larger variety of compositions, resembling anything from Earth analogs to

Francois Fressin; Suzanne Aigrain; David Charbonneau; Malcolm Fridlund; Tristan Guillot; Heather Knutson; Tsevi Mazeh; Frederic Pont; Heike Rauer; Guillermo Torres

2009-01-01

247

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

NASA Astrophysics Data System (ADS)

Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 M ? to 1 M J) in Jupiter's orbit at ~5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.

Quintana, Elisa V.; Lissauer, Jack J.

2014-05-01

248

STELLAR-MASS-DEPENDENT DISK STRUCTURE IN COEVAL PLANET-FORMING DISKS  

SciTech Connect

Previous studies suggest that the planet-forming disks around very low mass stars/brown dwarfs may be flatter than those around more massive stars, in contrast to model predictions of larger scale heights for gas-disks around lower-mass stars. We conducted a statistically robust study to determine whether there is evidence for stellar-mass-dependent disk structure in planet-forming disks. We find a statistically significant difference in the Spitzer/IRAC color distributions of disks around very low mass and low mass stars all belonging to the same star-forming region, the Chamaeleon I star-forming region. We show that self-consistently calculated flared disk models cannot fit the median spectral energy distributions (SEDs) of the two groups. These SEDs can only be explained by flatter disk models, consistent with the effect of dust settling in disks. We find that, relative to the disk structure predicted for flared disks, the required reduction in disk scale height is anti-correlated with the stellar mass; i.e., disks around lower-mass stars are flatter. Our results show that the initial and boundary conditions of planet formation are stellar-mass-dependent, an important finding that must be considered in planet formation models.

Szucs, Laszlo [Department of Experimental Physics, University of Szeged, Szeged, Dom ter 9, 6720 Hungary (Hungary); Apai, Daniel; Pascucci, Ilaria [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Dullemond, Cornelis P., E-mail: szucs@titan.physx.u-szeged.h, E-mail: apai@stsci.ed, E-mail: pascucci@stsci.ed, E-mail: dullemon@mpia.d [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany)

2010-09-10

249

Search for Habitable Planets Around Low-Mass Stars Using the InfraRed Doppler Instrument  

NASA Astrophysics Data System (ADS)

We present strategies and plans for a new Doppler exoplanet survey of late-M dwarf stars to search for Earth-mass planets in the habitable zone around low-mass stars using a new near-infrared instrument for the Subaru telescope (IRD).

Omiya, M.; Sato, B.; Harakawa, H.; Kuzuhara, M.; Hirano, T.; Narita, N.; IRD Team

2013-11-01

250

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

251

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

252

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

253

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

NASA Technical Reports Server (NTRS)

This is an artist's impression of the gas-giant planet orbiting the yellow, Sun-like star HD 209458, 150 light-years from Earth. Astronomers used NASA's Hubble Space Telescope to look at this world and make the first direct detection of an atmosphere around an extrasolar planet. The planet was not directly seen by Hubble. Instead, the presence of sodium was detected in light filtered through the planet's atmosphere when it passed in front of its star as seen from Earth (an event called a transit). The planet was discovered in 1999 by its subtle gravitational pull on the star. The planet is 70 percent the mass of Jupiter, the largest planet in our solar system. Its orbit is tilted nearly edge-on to Earth, which allows repeated transit observations. The planet is merely 4 million miles from the star. The distance between the pair is so close that the yellow star looms in the sky, with an angular diameter 23 times larger than the full Moon's diameter as seen from Earth, and glows 500 times brighter than our Sun. At this precarious distance the planet's atmosphere is heated to 2000 degrees Fahrenheit (1100 degrees Celsius). But the planet is big enough to hold onto its seething atmosphere. Illustration Credit: NASA and Greg Bacon (STScI/AVL)

2002-01-01

254

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

255

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

256

In search of planets and life around other stars.  

PubMed

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, J I

1999-05-11

257

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

258

The Masses of the Planets, Satellites, and Asteroids  

Microsoft Academic Search

A comprehensive compilation of the mass determinations, both historical and modern, of the natural bodies in our solar system is presented. A systematically determined weighted mean, based on all available fundamental independent determinations, is given for each body. The methods of determining the masses are described.

R. L. Duncombe; W. J. Klepcynski; P. K. Seidelman

1973-01-01

259

Jiggly Jupiter  

NSDL National Science Digital Library

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

260

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

261

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

NASA Technical Reports Server (NTRS)

The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

Debes, John H.; Jackson, Brian

2010-01-01

262

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

SciTech Connect

The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense Hubble Space Telescope search for transits. We find that in older clusters, one expects to detect fewer transiting planets by a factor of 2 for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of the semimajor axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

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

2010-11-10

263

Gravitational scattering by giant planets  

NASA Astrophysics Data System (ADS)

We seek to characterize giant-planet systems by their gravitational scattering properties. We do this to a given system by integrating it numerically along with a large number of hypothetical small bodies that are initially in eccentric habitable zone (HZ)-crossing orbits. Our analysis produces a single number, the escape rate, which represents the rate at which the small-body flux is perturbed away by the giant planets into orbits that no longer pose a threat to terrestrial planets inside the HZ. Obtaining the escape rate this way is similar to computing the largest Liapunov exponent as the exponential rate of divergence of two nearby orbits. For a terrestrial planet inside the HZ, the escape rate value quantifies the "protective" effect that the studied giant-planet system offers. Therefore, escape rates could provide information on whether certain giant-planet configurations produce a more desirable environment for life than the others. We present some computed escape rates on selected planetary systems, focusing on effects of varying the masses and semi-major axes of the giant planets. In the case of our Solar System we find rather surprisingly that Jupiter, in its current orbit, may provide a minimal amount of protection to the Earth.

Laakso, T.; Rantala, J.; Kaasalainen, M.

2006-09-01

264

HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES  

SciTech Connect

We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T{sub eff} > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

Winn, Joshua N.; Albrecht, Simon [Department of Physics, Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Fabrycky, Daniel [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Johnson, John Asher [Department of Astrophysics, NASA Exoplanet Science Institute, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)

2010-08-01

265

Jupiter's Water Worlds  

NASA Technical Reports Server (NTRS)

When the twin Voyager spacecraft cruised past Jupiter in 1979, they did more than rewrite the textbooks on the giant planet. Their cameras also unveiled the astounding diversity of the four planet-size moons of ice and stone known as the Galilean satellites. The Voyagers revealed the cratered countenance of Callisto, the valleys and ridges of Ganymede, the cracked face of Europa, and the spewing volcanoes of Io. But it would take a spacecraft named for Italian scientist Galileo, who discovered the moons in 1610, to reveal the true complexity of these worlds and to begin to divulge their interior secrets. Incredibly, the Galileo data strongly suggest that Jupiter's three large icy moons (all but rocky Io) hide interior oceans.

Pappalardo, R. T.

2004-01-01

266

Growing Jupiter the Hard Way  

NASA Astrophysics Data System (ADS)

Two competing hypotheses for the origin of jovian-type planets are gravitational instability in a circumstellar disk (Boss, Science 276, 1836, 1997), and accumulation of a massive core that accretes gas from the nebula (Pollack et al., Icarus 124, 62, 1996). The diversity of orbits among extrasolar planets and our own system suggests that both mechanisms may be effective, perhaps depending on the disk mass. I investigate the core-accretion model, using the PSI multi-zone code (Weidenschilling et al., Icarus 128, 429, 1997) to simulate growth of Jupiter's core, without simplifying assumptions used by Pollack et al. The surface density is not assumed uniform across the feeding zone, and planetesimals may migrate into or out of the feeding zone by gas drag. Gravitational stirring by the embryo is parameterized from Greenzweig and Lissauer (Icarus 100, 440, 1992), including a small but significant increase in inclination at each synodic encounter. While Pollack et al. assumed a Mars-sized "seed body" to initiate core growth, a much smaller (10(-3) M_?) body is sufficient. The background population of planetesimals (initial size 25 km) grows by mutual collisions. However, the seed body experiences runaway growth and maintains its advantage. It stirs velocities of the smaller bodies, inhibiting runaway of potential competitors. The embryo depletes the local population, creating a local minimum in the surface density. However, gas drag supplies new bodies to the feeding zone, allowing its growth to continue. For the nominal surface density of 10 g/cm(2) , the core gains about 1 M_? per million years. This is too slow to yield a core able to accrete gas during the probable lifetime of the nebula, but a modest increase in surface density allows formation of Jupiter's core. Still under investigation are the minimum "seed" mass required for emergence of a dominant embryo, and the role of collisional fragmentation among the smaller swarm bodies.

Weidenschilling, S. J.

1998-09-01

267

Habitable moons around extrasolar giant planets  

Microsoft Academic Search

Possible planetary objects have now been discovered1-9 orbiting nine different main-sequence stars. These companion objects (some of which might actually be brown dwarfs) all have a mass at least half that of Jupiter, and are therefore unlikely to be hospitable to Earth-like life: jovian planets and brown dwarfs support neither a solid nor a liquid surface near which organisms might

Darren M. Williams; James F. Kasting; Richard A. Wade

1997-01-01

268

Secondary Eclipse Observations of the Low-Mass Hot-Jupiter WASP-11b/HAT-P-10b  

NASA Astrophysics Data System (ADS)

WASP-11b/HAT-P-10b is a hot-Jupiter planet that orbits a K3 dwarf every 3.722 days at a distance of 0.0439 AU. Using the Spitzer Space Telescope in 2009 (Harrington, P.I.) and 2010 (Knutson, P.I), we observed five secondary eclipses of WASP-11b/HAT-P-10b: two in the 3.6-micron channel, two in the 4.5-micron channel, and one in the 8-micron channel. We present eclipse-depth measurements, estimates of infrared brightness temperatures, and the first constraints on the atmospheric pressure and temperature profile and chemical compositions. We also refine its orbit using our own secondary-eclipse measurements in combination with external radial-velocity and transit observations from both professional and amateur observers. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported in part by NASA Planetary Atmospheres grant NNX13AF38G.

Bowman, M. Oliver; Harrington, J.; Blecic, J.; Foster, A.; Stevenson, K. B.; Cubillos, P.; Collier Cameron, A.; UCF Exoplanets Group

2013-10-01

269

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

SciTech Connect

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

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

2010-07-10

270

Horseshoe periodic orbits in the restricted problem of three bodies for a sun-Jupiter mass ratio  

NASA Astrophysics Data System (ADS)

Segments of seven families of symmetric horseshoe periodic orbits of the restricted three body problem for a sun-Jupiter mass ratio have been numerically determined. Each family is found to have a region consisting of smooth horseshoe shaped orbits with the family evolving to orbits acquiring loops on both sides of the smooth horseshoes. The general evolution of these families is discussed and one in particular (Rabe's horseshoe is a member of this family) is described in more detail with the aid of computer plots of orbits in this family. The smooth horseshoes do not continuously evolve along one family but are members of many distinct families. The change in shape of the smooth horseshoe orbits is examined as they have closer approaches to Jupiter. Each family has a bifurcation with an asymmetric family of periodic orbits. The initial conditions and other quantities describing these bifurcation orbits are given. Starting from these orbits the initial segments of the asymmetric families has been determined.

Taylor, D. B.

1981-11-01

271

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

272

Elliptical instability in hot Jupiter systems  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

273

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

274

YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?  

SciTech Connect

Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside {approx}15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

Nesvorny, David [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

2011-12-15

275

Detection of Laplace-resonant three-planet systems from transit timing variations  

NASA Astrophysics Data System (ADS)

Transit timing variations (TTVs) are useful to constrain the existence of perturbing planets, especially in resonant systems where the variations are strongly enhanced. Here we focus on Laplace-resonant three-planet systems, and assume that the inner planet transits the star. A dynamical study is performed for different masses of the three bodies, with special attention to terrestrial planets. We consider a maximal time-span of ˜100 yr and discuss the shape of the inner planet TTVs curve. Using frequency analysis, we highlight the three periods related to the evolution of the system: two periods associated with the Laplace-resonant angle and the third one with the precession of the pericentres. These three periods are clearly detected in the TTVs of an inner giant planet perturbed by two terrestrial companions. Only two periods are detected for a Jupiter-Jupiter-Earth configuration (the ones associated with the giant interactions) or for three terrestrial planets (the Laplace periods). However, the latter system can be constrained from the inner planet TTVs. We finally remark that the TTVs of resonant three or two Jupiter systems mix up, when the period of the Laplace-resonant angle matches the pericentre precession of the two-body configuration. This study highlights the importance of TTVs long-term observational programmes for the detection of multiple-planet resonant systems.

Libert, A.-S.; Renner, S.

2013-04-01

276

Atmospheric Circulation of Hot Jupiters  

NASA Astrophysics Data System (ADS)

Roughly 40% of currently known extrasolar giant planets have orbital distances of 0.2 AU or less and are dubbed ``hot Jupiters'' because of their high effective temperatures (1000 K or more). Doppler techniques have yielded lower bounds on their masses, and the recent discovery that one such hot Jupiter (HD209458b) transits its parent star has provided estimates of radii and actual mass. More transit detections are sure to follow, and future detection of these objects in thermal and reflected light may allow observational estimates of albedo, effective temperature, and perhaps day-night temperature differences. Atmospheric dynamics will be required to explain these observations. The radius depends on the entropy of the (presumably convecting) interior, while the temperature at the emission-to-space level is set by thermal balance with the star. The two regions are connected by a statically stable layer whose properties depend on atmospheric dynamics, so the dynamical regime must be understood if the radius and effective temperature are to be explained simultaneously. Furthermore, day-night temperature differences are directly linked to dynamical timescales (and are probably 200 K or more). The circulation pattern also determine whether (and where) clouds exist, which influences the albedo and the depth to which stellar radiation penetrates. Here we present detailed dynamical simulations using the Explicit Planetary Isentropic Coordinate (EPIC) model of Dowling et al. (1998) to constrain the probable circulation regimes of hot Jupiters (focusing on HD209458b, with radius 1.4 RJ, mass 0.7 MJ, and period of 3.5 days). The simulations assume a synchronously rotating gas-giant (as expected for hot Jupiters) and parameterize the intense heating and cooling using a simple relaxation to a radiative equilibrium profile. The goals are to determine the number and speed of the jets, the day-night temperature differences, and regions of upwelling and downwelling (which is relevant for cloud formation). We will compare the simulation results to simple order-of-magnitude estimates, which suggest the importance of planetary rotation, the existence of several jets, and horiztonal winds of 200 m/sec or more.

Showman, A. P.; Guillot, T.

2000-10-01

277

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

NASA Astrophysics Data System (ADS)

In the core accretion hypothesis, giant planets form by gas accretion onto solid protoplanetary cores. The minimum (or critical) core mass to form a gas giant is typically quoted as 10 M ?. The actual value depends on several factors: the location in the protoplanetary disk, atmospheric opacity, and the accretion rate of solids. Motivated by ongoing direct imaging searches for giant planets, this study investigates core mass requirements in the outer disk. To determine the fastest allowed rates of gas accretion, we consider solid cores that no longer accrete planetesimals, as this would heat the gaseous envelope. Our spherical, two-layer atmospheric cooling model includes an inner convective region and an outer radiative zone that matches onto the disk. We determine the minimum core mass for a giant planet to form within a typical disk lifetime of 3 Myr. The minimum core mass declines with disk radius, from ~8.5 M ? at 5 AU to ~3.5 M ? at 100 AU, with standard interstellar grain opacities. Lower temperatures in the outer disk explain this trend, while variations in disk density are less influential. At all distances, a lower dust opacity or higher mean molecular weight reduces the critical core mass. Our non-self-gravitating, analytic cooling model reveals that self-gravity significantly affects early atmospheric evolution, starting when the atmosphere is only ~10% as massive as the core.

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

2014-05-01

278

Gravity Waves in Jupiter's Upper Atmosphere  

Microsoft Academic Search

The Atmospheric Structure Instrument (ASI) on the Galileo Probe measured the temperature profile of Jupiter's atmosphere from a few nbar to a few bars. For the first time, there exists an accurate temperature profile of a giant planet thermosphere. The temperature gradients in Jupiter's thermosphere are large (2-3 K\\/km) and sustained; the maximum temperature reached is a surprising 1300 K

Leslie A. Young; Roger V. Yelle; Richard E. Young; Alvin Seiff; Donn B. Kirk

1996-01-01

279

Mr. Mills Reports on Jupiter Flyby.  

National Technical Information Service (NTIS)

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

1994-01-01

280

A nebula of gases from Io surrounding Jupiter.  

PubMed

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

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

2002-02-28

281

CoRoT's first seven planets: An overview  

NASA Astrophysics Data System (ADS)

The up to 150 day uninterrupted high-precision photometry of about 100000 stars - provided so far by the exoplanet channel of the CoRoT space telescope - gave a new perspective on the planet population of our galactic neighbourhood. The seven planets with very accurate parameters widen the range of known planet properties in almost any respect. Giant planets have been detected at low metallicity, rapidly rotating and active, spotted stars. CoRoT-3 populated the brown dwarf desert and closed the gap of measured physical properties between standard giant planets and very low mass stars. CoRoT extended the known range of planet masses down-to 5 Earth masses and up to 21 Jupiter masses, the radii to less than 2 Earth radii and up to the most inflated hot Jupiter found so far, and the periods of planets discovered by transits to 9 days. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planet-host-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that terrestrial planets with a density close to Earth exist outside the Solar System. The detection of the secondary transit of CoRoT-1 at the 10-5-level and the very clear detection of the 1.7 Earth radii of CoRoT-7b at 3.5 10-4 relative flux are promising evidence of CoRoT being able to detect even smaller, Earth sized planets. The CoRoT space mission has been developed and is operated by CNES with the contribution of Austria, Belgium, Brazil, ESA, Germany and Spain.

Dvorak, R.; Schneider, J.; Lammer, H.; Barge, P.; Wuchterl, G.

2011-07-01

282

Microlensing Constraints on the Abundance of Extrasolar Planets  

NASA Astrophysics Data System (ADS)

Galactic gravitational microlensing is a powerful technique to detect extrasolar planets at large orbital distances from their stars, from giant down to Earth-mass planets. We report a statistical analysis (Cassan et al. 2012) that combines six years of microlensing observations gathered between 2002 to 2007 by the PLANET and OGLE collaborations. From these data, we estimate the frequency of cool extrasolar planets, with masses ranging from 5 Earths to 10 Jupiters and orbits between 0.5 to 10 Astronomical Units. We find that in average, one in six stars has a Jupiter-like gas giant as companion planet, that about half the stars are orbited by a Neptune-like giant, and two-thirds are associated to super-Earths. Our study also suggests that planets should be ubiquitous throughout the Galaxy. Current deployment of wide-field imagers and possible space-based observations onboard ESA spacecraft EUCLID will soon allow a large increase of the number of monitored microlensing events. These new observatories should provide in a near future a more detailed view on planet abundance as a function of mass.

Cassan, Arnaud; PLANET Collaboration; OGLE Collaboration

2014-04-01

283

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

284

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

285

Searching for Planets Around other Stars  

NASA Technical Reports Server (NTRS)

In this colloquim presentation, Professor of Astronomy, Geoffrey Marcy discusses the discovery of planets orbiting other stars. Using the Doppler shift caused by stellar wobble that is caused by nearby planetary mass, astronomers have been able to infer the existence of Jupiter-sized planets around other stars. Using a special spectrometer at Lick Observatory, the wobble of several stars have been traced over the years required to generate an accurate pattern required to infer the stellar wobble. Professor Marcy, discusses the findings of planets around 47 Ursae Majoris, 16 Cygni B, 51 Pegasus, and 56 Rho 1 Cne. In the case of 56 Rho 1 Cne the planet appears to be close to the star, within 1.5 astronomical units. The observations from the smaller Lick Observatory will be augmented by new observations from the larger telescope at the Kek observatory. This move will allow observations of smaller planets, as opposed to the massive planets thus far discovered. The astronomers also hope to observe smaller stars with the Kek data. Future spaceborne observations will allow the discovery of even smaller planets. A spaceborne interferometer is in the planning stages, and an even larger observatory, called the Terrestrial Planet Finder, is hoped for. Professor Marcy shows artists' renderings of two of the planets thus far discovered. He also briefly discusses planetary formation and shows slides of both observations from the Orion Nebula and models of stellar system formation.

1998-01-01

286

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

287

The occurrence of Jovian planets and the habitability of planetary systems  

PubMed Central

Planets of mass comparable to or larger than Jupiter's have been detected around over 50 stars, and for one such object a definitive test of its nature as a gas giant has been accomplished with data from an observed planetary transit. By virtue of their strong gravitational pull, giant planets define the dynamical and collisional environment within which terrestrial planets form. In our solar system, the position and timing of the formation of Jupiter determined the amount and source of the volatiles from which Earth's oceans and the source elements for life were derived. This paper reviews and brings together diverse observational and modeling results to infer the frequency and distribution of giant planets around solar-type stars and to assess implications for the habitability of terrestrial planets.

Lunine, Jonathan I.

2001-01-01

288

The occurrence of Jovian planets and the habitability of planetary systems.  

PubMed

Planets of mass comparable to or larger than Jupiter's have been detected around over 50 stars, and for one such object a definitive test of its nature as a gas giant has been accomplished with data from an observed planetary transit. By virtue of their strong gravitational pull, giant planets define the dynamical and collisional environment within which terrestrial planets form. In our solar system, the position and timing of the formation of Jupiter determined the amount and source of the volatiles from which Earth's oceans and the source elements for life were derived. This paper reviews and brings together diverse observational and modeling results to infer the frequency and distribution of giant planets around solar-type stars and to assess implications for the habitability of terrestrial planets. PMID:11158551

Lunine, J

2001-01-30

289

Modifications of the electrodynamic interaction between Jupiter and Io due to mass loading effects  

NASA Astrophysics Data System (ADS)

The electrodynamic interaction between Jupiter and Io is investigated by means of three-dimensional resistive MHD simulations with Jupiter being modeled as an aligned rotator situated in the origin of a cylindrical coordinate system. For numerical reasons, however, only qualitative statements can be made, which do not allow quantitative comparisons with observations. The main topic is the generation of electric currents parallel to the magnetic field. In consideration of the fact that some observational features cannot be qualitatively understood with present theories, the rôle of the plasma production from Io's atmosphere as well as by ionization in the plasma torus is investigated. If these two plasma sources are significantly cooler than the plasma environment, they can be shown to cause a torus corotational lag, in consequence of which a field-aligned current system develops. If microinstabilities occur along this system, anomalous resistivity regions may be built up where the electric field attains a component parallel to the magnetic field. Thus ionization within the torus might explain the observed decametric radiation upstream of Io's current position. Furthermore, plasma production from Io's atmosphere shows a strong influence on the MHD modes excited by the Io/torus interaction. The pressure signatures generated by slow mode perturbations disclose the formation of a tail-like structure in the wake behind Io. Thus previous conceptions about a new current systems in Io's wake can be confirmed by self-consistent MHD simulations. Finally, the correlations between this current and gradients in angular velocity and density are studied in detail.

Kopp, Andreas

1996-11-01

290

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

291

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

NASA Astrophysics Data System (ADS)

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

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

2009-01-01

292

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

293

The planets and life.  

NASA Technical Reports Server (NTRS)

It is pointed out that planetary exploration is not simply a program designed to detect life on another planet. A planet similar to earth, such as Mars, when studied for evidence as to why life did not arise, may turn out to be scientifically more important than a planet which has already produced a living system. Of particular interest after Mars are Venus and Jupiter. Jupiter has a primitive atmosphere which may well be synthesizing organic molecules today. Speculations have been made concerning the possibility of a bio-zone in the upper atmosphere of Venus.

Young, R. S.

1971-01-01

294

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

PubMed

The discovery of two Earth-mass planets orbiting an old ( approximately 10(9) years), rapidly spinning neutron star, the 6.2-millisecond radio pulsar PSR B1257+12, was announced in early 1992. It was soon pointed out that the approximately 3:2 ratio of the planets' orbital periods should lead to accurately predictable and possibly measurable gravitational perturbations of their orbits. The unambiguous detection of this effect, after 3 years of systematic timing observations of PSR B1257+12 with the 305-meter Arecibo radiotelescope, as well as the discovery of another, moon-mass object in orbit around the pulsar, constitutes irrefutable evidence that the first planetary system around a star other than the sun has been identified. PMID:17732735

Wolszczan, A

1994-04-22

295

The phase-dependent infrared brightness of the extrasolar planet upsilon Andromedae b.  

PubMed

The star upsilon Andromedae is orbited by three known planets, the innermost of which has an orbital period of 4.617 days and a mass at least 0.69 that of Jupiter. This planet is close enough to its host star that the radiation it absorbs overwhelms its internal heat losses. Here, we present the 24-micrometer light curve of this system, obtained with the Spitzer Space Telescope. It shows a variation in phase with the orbital motion of the innermost planet, demonstrating that such planets possess distinct hot substellar (day) and cold antistellar (night) faces. PMID:17038587

Harrington, Joseph; Hansen, Brad M; Luszcz, Statia H; Seager, Sara; Deming, Drake; Menou, Kristen; Cho, James Y-K; Richardson, L Jeremy

2006-10-27

296

The Phase-Dependent Infrared Brightness of the Extrasolar Planet ? Andromedae b  

NASA Astrophysics Data System (ADS)

The star ? Andromedae is orbited by three known planets, the innermost of which has an orbital period of 4.617 days and a mass at least 0.69 that of Jupiter. This planet is close enough to its host star that the radiation it absorbs overwhelms its internal heat losses. Here, we present the 24-micrometer light curve of this system, obtained with the Spitzer Space Telescope. It shows a variation in phase with the orbital motion of the innermost planet, demonstrating that such planets possess distinct hot substellar (day) and cold antistellar (night) faces.

Harrington, Joseph; Hansen, Brad M.; Luszcz, Statia H.; Seager, Sara; Deming, Drake; Menou, Kristen; Cho, James Y.-K.; Richardson, L. Jeremy

2006-10-01

297

New Planets Detected with the Hobby-Eberly Telescope  

Microsoft Academic Search

The High Resolution Spectrograph on the Hobby-Eberly Telescope is now routinely producing stellar radial velocities with a precision of 2-3 meters\\/second. This velocity precision, coupled with queue-mode observing, has allowed us to detect planetary companions to two stars: HD 37605 and rho 1 Cancri. The companion to HD 37605 has a minimum mass of 2.84 Jupiter masses. The planet is

W. D. Cochran; M. Endl; B. E. McArthur

2004-01-01

298

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

299

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

300

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

301

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 ...

Larsen, Mr.

2008-11-25

302

Jupiter - Observation of deuterated methane in the atmosphere.  

NASA Technical Reports Server (NTRS)

During May 1971 a number of whole-planet spectra of Jupiter were obtained. Strongly evident in the spectrum of Jupiter are several J-manifolds in the P-branch of a band of CH3D. It is believed that this is the first observation of deuterium in any astronomical source. The spectrum of Jupiter is shown together with the spectrum of the sun, and a representation of a ratio of the spectrum of Jupiter to that of the sun.

Beer, R.; Farmer, C. B.; Norton, R. H.; Martonchik, J. V.; Barnes, T. G.

1972-01-01

303

Voyager picture of Jupiter  

NASA Technical Reports Server (NTRS)

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

1998-01-01

304

The phase-dependent Infrared brightness of the extrasolar planet upsilon Andromedae b  

Microsoft Academic Search

The star upsilon Andromeda is orbited by three known planets, the innermost\\u000aof which has an orbital period of 4.617 days and a mass at least 0.69 that of\\u000aJupiter. This planet is close enough to its host star that the radiation it\\u000aabsorbs overwhelms its internal heat losses. Here we present the 24 micron\\u000alight curve of this system,

J. Harrington; B. Hansen; S. Luszcz; S. Seager; D. Deming; K. Menou; J. Cho; L. J. Richardson

2006-01-01

305

The Phase-Dependent Infrared Brightness of the Extrasolar Planet upsilo Andromedae b  

Microsoft Academic Search

The star upsilo Andromedae is orbited by three known planets, the innermost of which has an orbital period of 4.617 days and a mass at least 0.69 that of Jupiter. This planet is close enough to its host star that the radiation it absorbs overwhelms its internal heat losses. Here, we present the 24-micrometer light curve of this system, obtained

Joseph Harrington; Brad M. Hansen; Statia H. Luszcz; Sara Seager; Drake Deming; Kristen Menou; James Y.-K. Cho; L. Jeremy Richardson

2006-01-01

306

A 5 Micron of beta Pictoris B at a Sub-Jupiter Projected Separation: Evidence for a Misalignment Between the Planet and the Inner, Warped Disk  

NASA Technical Reports Server (NTRS)

We present and analyze a new M' detection of the young exoplanet Beta Pictoris b from 2008 VLT/NaCo data at a separation of approx. = 4 AU and a high signal-to-noise rereduction of L' data taken in December 2Q09. Based on our orbital analysis, the planet's orbit is viewed almost perfectly edge-on (i approx. 89 degrees) and has a Saturn-like semimajor axis of 9.50AU(+3.93 AU)/-(1.7AU) . Intriguingly, the planet's orbit is aligned with the major axis of the outer disk (Omega approx.31 degrees) but probably misaligned with the warp/inclined disk at 80 AU often cited as a signpost for the planet's existence. Our results motivate new studies to clarify how Beta Pic b sculpts debris disk structures and whether a second planet is required to explain the warp/inclined disk

Currie, Thayne; Thalmann, Christian; Matsumura, Soko; Madhusudhan, Nikku; Burrows, Adam; Kuchner, Marc

2011-01-01

307

Gravity Assist from Jupiter'S Moons for Jupiter-Orbiting Space Missions.  

National Technical Information Service (NTIS)

The report describes results of an investigation of the propellant economies of using the gravitational attraction of Jupiter's four large moons to effect the transfer of a spacecraft into orbit around that planet. Use of a simplified model to approximate...

R. W. Longman

1968-01-01

308

The origin of retrograde hot Jupiters  

NASA Astrophysics Data System (ADS)

Many hot Jupiters are observed to be misaligned with respect to the rotation axis of the star (as measured through the Rossiter-McLaughlin effect) and some (about ~ 25%) even appear to be in retrograde orbits. We show that the presence of an additional, moderately inclined and eccentric massive planet in the system can naturally explain close, inclined, eccentric, and even retrograde orbits. We have derived a complete and accurate treatment of the secular dynamics including both the key octupole-order effects and tidal friction. The flow of angular momentum from the inner orbit to the orbit of the perturber can lead to both high eccentricities and inclinations, and even flip the inner orbit. In our treatment the component of the inner orbit's angular momentum perpendicular to the stellar equatorial plane can change sign; a brief excursion to very high eccentricity during the chaotic evolution of the inner orbit can then lead to rapid ``tidal capture,'' forming a retrograde hot Jupiter. Previous treatments of the secular dynamics focusing on stellar-mass perturbers would not allow for such an outcome, since in that limit the component of the inner orbit's angular momentum perpendicular to the stellar equatorial plane is strictly conserved. Thus, the inclination of the planet's orbit could not change from prograde to retrograde.

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

2011-11-01

309

MEASURE-Jupiter: Low Cost Missions to Explore Jupiter in the Post-Galileo Era  

NASA Technical Reports Server (NTRS)

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

Wallace, R.; Stetson, D.; West, R.; Stern, S.

1994-01-01

310

The Jupiter Ganymede Orbiter : An ESA Contribution to the Europa-Jupiter System Mission  

Microsoft Academic Search

In the framework of an outer planets mission, under study after the NASA-Juno mission, the Europa-Jupiter System Mission (EJSM) would combine a fleet of up to three satellites in order to investigate in depth many questions related to the Jupiter System. These investigations are essential for our understanding of the emergence and evolution of habitable worlds, not only within the

Pierre Drossart; M. Blanc; J. P. Lebreton; R. T. Pappalardo; R. Greeley; M. Fujimoto

2008-01-01

311

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

312

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

313

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

314

Prospects for the detection of planets around very low-mass primaries  

NASA Astrophysics Data System (ADS)

Progress in the understanding of very low-mass stars and brown dwarfs has developed at a fast pace in the last decade. Several pieces of evidence indicate that these very low-mass objects form in a manner similar to stars, and hence it appears natural to that they could host planetary systems. We are carrying out studies of the binary properties of very low-mass primaries, some new results will be presented. We have also embarked on a project to design, build and exploit a high-precision near-infrared echelle spectrograph for planet dection around very low-mass primaries. This instrument, called NAHUAL, is being designed for installation at the 10.4 m Gran Telescopio Canarias in La Palma, Canary Islands. The current status of the project will be discussed, as well as opportunities for the latino-american scientific community to participate.

Martín, E.; Urania Cabral, C. V.

2009-05-01

315

Planet Formation  

NASA Astrophysics Data System (ADS)

1. Historical notes on planet formation Bodenheimer; 2. The formation and evolution of planetary systems Bouwman et al.; 3. Destruction of protoplanetary disks by photoevaporation Richling, Hollenbach and Yorke; 4. Turbulence in protoplanetary accretion disks Klahr, Rozyczka, Dziourkevitch, Wunsch and Johansen; 5. The origin of solids in the early solar system Trieloff and Palme; 6. Experiments on planetesimal formation Wurm and Blum; 7. Dust coagulation in protoplanetary disks Henning, Dullemond, Wolf and Dominik; 8. The accretion of giant planet cores Thommes and Duncan; 9. Planetary transits: direct vision of extrasolar planets Lecavelier des Etangs and Vidal-Madjar; 10. The core accretion - gas capture model Hubickyj; 11. Properties of exoplanets Marcy, Fischer, Butler and Vogt; 12. Giant planet formation: theories meet observations Boss; 13. From hot Jupiters to hot Neptures … and below Lovis, Mayor and Udry; 14. Disk-planet interaction and migration Masset and Kley; 15. The Brown Dwarf - planet relation Bate; 16. From astronomy to astrobiology Brandner; 17. Overview and prospective Lin.

Klahr, Hubert; Brandner, Wolfgang

2011-02-01

316

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

National Technical Information Service (NTIS)

The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact t...

B. Jackson J. H. Debes

2010-01-01

317

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

318

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

319

TWO 'b's IN THE BEEHIVE: THE DISCOVERY OF THE FIRST HOT JUPITERS IN AN OPEN CLUSTER  

SciTech Connect

We report the discovery of two giant planets orbiting stars in Praesepe (also known as the Beehive Cluster). These are the first known hot Jupiters in an open cluster and the only planets known to orbit Sun-like, main-sequence stars in a cluster. The planets are detected from Doppler-shifted radial velocities; line bisector spans and activity indices show no correlation with orbital phase, confirming the variations are caused by planetary companions. Pr0201b orbits a V = 10.52 late F dwarf with a period of 4.4264 {+-} 0.0070 days and has a minimum mass of 0.540 {+-} 0.039 M{sub Jup}, and Pr0211b orbits a V = 12.06 late G dwarf with a period of 2.1451 {+-} 0.0012 days and has a minimum mass of 1.844 {+-} 0.064 M{sub Jup}. The detection of two planets among 53 single members surveyed establishes a lower limit of 3.8{sup +5.0}{sub -2.4}% on the hot Jupiter frequency in this metal-rich open cluster. Given the precisely known age of the cluster, this discovery also demonstrates that, in at least two cases, giant planet migration occurred within 600 Myr after formation. As we endeavor to learn more about the frequency and formation history of planets, environments with well-determined properties-such as open clusters like Praesepe-may provide essential clues to this end.

Quinn, Samuel N.; White, Russel J.; Cantrell, Justin R. [Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302 (United States); Latham, David W.; Furesz, Gabor; Szentgyorgyi, Andrew H.; Geary, John C.; Torres, Guillermo; Bieryla, Allyson; Berlind, Perry; Calkins, Michael C.; Esquerdo, Gilbert A.; Stefanik, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Dahm, Scott E. [W. M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States)

2012-09-10

320

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

321

A Framework For Characterizing The Atmospheres Of GJ 1214b-type Low-mass Low-density Transiting Planets  

NASA Astrophysics Data System (ADS)

The atmosphere of the low-mass low-density transiting planet GJ 1214b has been extensively characterized via transmission spectroscopy. Observations include spectra and photometric points from blue to mid-infrared wavelengths. The transmission spectrum appears relatively featureless, indicating an atmosphere that does not show strong molecular absorption features. It has been suggested that this ``flat" spectrum could be due to an obscuring grey cloud/haze layer, or due to a high mean molecular weight (MMW) atmosphere. If the planet is similar to a scaled down version of Uranus or Neptune, as suggested by Nettelmann et al. (2011), both explanations could well be viable. To lift the degeneracy of these explanations, one can imagine characterizing a range of similar planets, which are now being found. Here we examine the structure and atmospheres of volatile-rich planets from 5-20 Earth masses and T_eq from 100 - 1500 K. Based on population synthesis models of core-accretion planet formation, we examine the expected Z_atmosphere and MMW these low mass planets. We examine how atmospheric escape of the outermost layers of such planets may expose deeper atmospheric layers with less hydrogen and a higher Z_atmosphere and MMW. We note that the hottest variants of these planets should feature atmospheres rich in CO, rather than CH4, potentially eliminating a pathway to photochemical haze formation. We provide a synthesis of these physical effects over a range of mass, temperature, and metallicity parameters. We highlight where in parameter space these GJ 1214b and Neptune-like planets are likely to have atmospheres that are most amenable to characterization from transmission spectroscopy.

Fortney, Jonathan J.; Nettelmann, N.; Kempton, E.; Mordasini, C.; Zahnle, K.; Lopez, E.; Morley, C. V.; Marley, M. S.

2012-10-01

322

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

323

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

324

An improved method for estimating the masses of stars with transiting planets  

NASA Astrophysics Data System (ADS)

Context. To determine the physical parameters of a transiting planet and its host star from photometric and spectroscopic analysis, it is essential to independently measure the stellar mass. This is often achieved by the use of evolutionary tracks and isochrones, but the mass result is only as reliable as the models used. Aims: The recent paper by Torres et al. (2010, A&ARv, 18, 67) showed that accurate values for stellar masses and radii could be obtained from a calibration using Teff, log g and [Fe/H]. We investigate whether a similarly good calibration can be obtained by substituting log ? - the fundamental parameter measured for the host star of a transiting planet - for log g, and apply this to star-exoplanet systems. Methods: We perform a polynomial fit to stellar binary data provided in Torres et al. (2010) to obtain the stellar mass and radius as functions of Teff, log ? and [Fe/H], with uncertainties on the fit produced from a Monte Carlo analysis. We apply the resulting equations to measurements for seventeen SuperWASP host stars, and also demonstrate the application of the calibration in a Markov Chain Monte Carlo analysis to obtain accurate system parameters where spectroscopic estimates of effective stellar temperature and metallicity are available. Results: We show that the calibration using log ? produces accurate values for the stellar masses and radii; we obtain masses and radii of the SuperWASP stars in good agreement with isochrone analysis results. We ascertain that the mass calibration is robust against uncertainties resulting from poor photometry, although a good estimate of stellar radius requires good-quality transit light curve to determine the duration of ingress and egress.

Enoch, B.; Collier Cameron, A.; Parley, N. R.; Hebb, L.

2010-06-01

325

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

326

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

327

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

328

Jupiter. [internal structure and atmosphere  

NASA Technical Reports Server (NTRS)

The physical structure of Jupiter is discussed on the basis of data obtained by Pioneers 10 and 11. It is argued that the elemental composition of Jupiter is similar to that of the sun, and it is shown that this argument is supported by measurements of the planet's density and H/He ratio. Jupiter's shape and gravitational field are described, and a model of the planet is proposed in which there are a small iron-silicate core at the center, a very thick liquid-hydrogen stratum divided into metallic (inner) and molecular (outer) layers, and a gaseous atmosphere. According to this model, the excess heat radiated by Jupiter is simply a remnant of the heat generated when the planet coalesced from the solar nebula. The appearance of the planetary disk is described together with the Jovian magnetic field, and the Great Red Spot is shown to be a cyclonic disturbance similar to a hurricane. Effects of the Galilean satellites on the magnetic field are considered.

Wolfe, J. H.

1975-01-01

329

5 Micron of beta Pictoris B at a Sub-Jupiter Projected Separation: Evidence for a Misalignment Between the Planet and the Inner, Warped Disk.  

National Technical Information Service (NTIS)

We present and analyze a new M' detection of the young exoplanet Beta Pictoris b from 2008 VLT/NaCo data at a separation of approx. = 4 AU and a high signal-to-noise rereduction of L' data taken in December 2Q09. Based on our orbital analysis, the planet'...

A. Burrows C. Thalmann M. Kuchner N. Madhusudhan S. Matsumura T. Currie

2011-01-01

330

Planets and Brown Dwarfs and Stars, Oh My! --- Companions Along the Road to the Nearest Stars  

NASA Astrophysics Data System (ADS)

RECONS (www.recons.org, REsearch Consortium On Nearby Stars) has been using astrometric techniques since 1999 to search for massive planets orbiting more than 130 nearby red and white dwarfs. Because of their proximity, nearby stars are natural locations to search for other solar systems --- the stars provide increased fluxes, larger astrometric perturbations, and higher probabilities for eventual resolution of planets than similar stars at larger distances. Unlike radial velocity searches, our astrometric effort is most sensitive to Jovian planets in Jovian orbits, i.e. those that span decades. We have discovered stellar companions with masses of a few hundred Jupiters, brown dwarf companions with masses of a few tens of Jupiters, and are now pushing into the realm of planets with masses of a few Jupiters around the nearest red dwarfs. Several previously unknown companions have been imaged via Gemini-AO observations, but we have also detected perturbations caused by enigmatic companions that elude direct detection. As we sweep through the mass regimes of stars to exoplanets for companions, we are now able to assess the various populations --- stars are common as companions, whereas brown dwarfs and massive planets are rare. We outline what we have discovered so far and place our exoplanet search results in context with an overview of the census of more than 60 stars with exoplanets known within 25 pc. This effort is supported by the NSF through grant AST-0908402 and via observations made possible by the SMARTS Consortium.

Henry, Todd J.; Davison, C. L.; Dieterich, S. B.; Ianna, P. A.; Jao, W. C.; Koerner, D. W.; Subasavage, J. P.; Tanner, A. M.; White, R. J.; RECONS

2012-01-01

331

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

332

Formation of Planets Around the Sun and Other Stars.  

ScienceCinema

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.

333

Small Inner Companions of Warm Jupiters: Lifetimes and Legacies  

NASA Astrophysics Data System (ADS)

Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

Van Laerhoven, Christa; Greenberg, Richard

2013-12-01

334

Warm dust in systems with transiting planets  

NASA Astrophysics Data System (ADS)

Debris disks are known to exist around many planethost stars, but no debris dust has been discovered so far in systems with planets detected by the transit method. We have found six systems, each with one transiting "hot Jupiter", that possess significant excess emission in themid-infrared. These are CoRoT-14, XO-5, HATP- 5, TrES-2, CoRoT-10, and CoRoT-8. Modeling suggests that the observed excesses stem from dust rings with radii between about 0.1 AU and 25 AU and dust masses in the range from about ˜ 10-7 to ˜ 10-3 Earth masses. In some systems dust may be produced by collisional cascade in asteroid belt analogs, while in some others a transient nature of dust appears more likely. The presence of debris dust may put important constraints onto scenarios of formation and migration of hot Jupiters.

Krivov, A. V.; Reidemeister, M.; Fiedler, S.; Löhne, T.

2011-10-01

335

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

336

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

337

ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search) Hunting for planets of Earth mass and below  

Microsoft Academic Search

Gravitational microlensing observations will lead to a census of planets that orbit stars of different populations. From 2008, ARTEMiS will provide an expert system that allows to adopt a three-step strategy of survey, follow-up and anomaly monitoring of gravitational microlensing events that is capable of detecting planets of Earth mass and below. The SIGNALMEN anomaly detector, an integral part, has

Martin Dominik; Keith Horne; Alasdair Allan; Nicholas J. Rattenbury; Yiannis Tsapras; Colin Snodgrass; Michael F. Bode; Martin J. Burgdorf; Stephen N. Fraser; Eamonn Kerins; Christopher J. Mottram; Iain A. Steele; Peter J. Wheatley; Lukasz Wyrzykowski

2008-01-01

338

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

339

Depiction of Hot Jupiter World  

NASA Video Gallery

Planets that are more than twice the diameter of Earth have about ten Earth masses and enough gravity to hold onto hydrogen, the most abundant element in the Universe. Such large planets turn into ...

340

Extrasolar Planets: New Clues for Planet Formation  

Microsoft Academic Search

Approximately 50 low-mass companions to solar type stars have been discovered using high precision radial velocity techniques. Recent discoveries include planets with minimum masses below that of Saturn, many systems with indications of multiple planets, and a jovian-mass companion to one of the nearest stars to the sun, epsilon Eridani. We review the present status of extrasolar planet candidates. The

W. D. Cochran

2000-01-01

341

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

342

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

343

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

Microsoft Academic Search

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

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

2010-01-01

344

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

345

Types of gaseous envelopes of "hot Jupiter" exoplanets  

NASA Astrophysics Data System (ADS)

As a rule, the orbital velocities of "hot Jupiters," i.e., exoplanets with masses comparable to the mass of Jupiter and orbital semi-major axes less than 0.1 AU, are supersonic relative to the stellar wind, resulting in the formation of a bow shock. Gas-dynamical modeling shows that the gaseous envelopes around hot Jupiters can belong to two classes, depending on the position of the collision point. if the collision point is inside the Roche lobe of the planet, the envelopes have the almost spherical shapes of classical atmospheres, slightly distorted by the influence of the star and interactions with the stellar-wind gas; if the collision point is located outside the Roche lobe, outflows from the vicinity of the Lagrangian points L1 and L2 arise, and the envelope becomes substantially asymmetrical. The latter class of objects can also be divided into two types. If the dynamical pressure of the stellar-wind gas is high enough to stop the most powerful outflow from the vicinity of the inner Lagrangian point L1, a closed quasi-spherical envelope with a complex shape forms in the system. If the wind is unable to stop the outflow from L1, an open aspherical envelope forms. The possible existence of atmospheres of these three types is confirmed by 3D numerical modeling. Using the typical hot Jupiter HD 209458b as an example, it is shown that all three types of atmospheres could exist within the range of estimated parameters of this planet. Since different types of envelopes have different observational manifestations, determining the type of envelope in HD 209458b could apply additional constrains on the parameters of this exoplanet.

Bisikalo, D. V.; Kaigorodov, P. V.; Ionov, D. E.; Shematovich, V. I.

2013-10-01

346

THE NASA-UC ETA-EARTH PROGRAM. II. A PLANET ORBITING HD 156668 WITH A MINIMUM MASS OF FOUR EARTH MASSES  

SciTech Connect

We report the discovery of HD 156668 b, an extrasolar planet with a minimum mass of M{sub P} sin i = 4.15 M{sub +}. This planet was discovered through Keplerian modeling of precise radial velocities from Keck-HIRES and is the second super-Earth to emerge from the NASA-UC Eta-Earth Survey. The best-fit orbit is consistent with circular and has a period of P = 4.6455 days. The Doppler semi-amplitude of this planet, K = 1.89 m s{sup -1}, is among the lowest ever detected, on par with the detection of GJ 581 e using HARPS. A longer period (P {approx} 2.3 years), low-amplitude signal of unknown origin was also detected in the radial velocities and was filtered out of the data while fitting the short-period planet. Additional data are required to determine if the long-period signal is due to a second planet, stellar activity, or another source. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 156668 (an old, quiet K3 dwarf) is photometrically constant over the radial velocity period to 0.1 mmag, supporting the existence of the planet. No transits were detected down to a photometric limit of {approx}3 mmag, ruling out transiting planets dominated by extremely bloated atmospheres, but not precluding a transiting solid/liquid planet with a modest atmosphere.

Howard, Andrew W.; Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Johnson, John Asher [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Wright, Jason T. [Center for Exoplanets and Habitable Worlds, Pennsylvania State University, University Park, PA 16802 (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); Valenti, Jeff A.; Anderson, Jay [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Piskunov, Nikolai E., E-mail: howard@astro.berkeley.edu [Department of Astronomy and Space Physics, Uppsala University, Box 515, 751 20 Uppsala (Sweden)

2011-01-10

347

Volatiles Inventory to the Inner Planets Due to Small Bodies Migration  

NASA Technical Reports Server (NTRS)

The concurrent processes of endogeneous and exogeneous origin are assumed to be responsible for the volatile reserves in the terrestrial planets. Volatiles inventory through collisions is rooted in orbital dynamics of small bodies including near-Earth objects (NEOs), short and long-period comets, and trans-Neptunian objects (TNOs), the latter probably supplying a large amount of Jupiter crossing objects (JCOs). Our model testifies that even a relatively small portion (approx. 0.001) of JCOs which transit to orbits with aphelia inside Jupiter's orbit (Q<4.7 AU) and reside such orbits during more than 1 Myr may contribute significantly in collisions with the terrestrial planets. The total mass of volatiles delivered to the Earth from the feeding zone of the giant planets could be greater than the mass of the Earth's oceans.

Marov, M. Y.; Ipatov, S. I.

2003-01-01

348

A planet around the evolved intermediate-mass star HD 110014  

NASA Astrophysics Data System (ADS)

Context: We found evidence for a sub-stellar companion around the K giant star HD 110014. This cool evolved star, with a spectral type K2III and an estimated mass between 1.9 and 2.4 M?, is slightly metal rich with [Fe/H] = 0.19 and a rotational velocity V sin i = 2.0 km s-1. Aims: To search for extrasolar planets around intermediate-mass stars and to improve our knowledge of the nature of radial velocity variations shown by G and K giant stars. Methods: Based on radial velocity analysis, we found evidence for a substellar companion with a planetary mass and long orbital period. The Radial velocity variation of HD 110014 has been monitored from 2000 until 2007 with FEROS at 1.5 m ESO and at the 2.2 m MPG/ESO, HARPS at the 3.6 m ESO and Coralie at 1.2 m Leonard Euler swiss telescopes in La Silla observatory. The radial velocities were computed by using a cross-correlation technique. Line bisector, Hipparcos photometry and chromospheric lines were analyzed to exclude other root-causes for the radial velocity variability. Results: We report the presence of an extrasolar planet around the giant star HD 110014, with an orbital period of 835.48 ± 6.04 days. A Keplerian orbit, with an eccentricity e = 0.462± 0.069, yields a minimum mass M sin i = 11.09 MJup. The analysis of the residuals shows evidence for a second RV variability with a period of 130 days and an amplitude of ±100 ms-1 . Its nature is not completely clear, but a second planet is a possible explanation. Based on observations collected at the 1.52-m ESO telescope (1999 to 2002), at the 2.2-m MPG/ESO telescope (2003 to 2007), at the 3.60 ESO telescope and at the Euler swiss telescope, at the La Silla Observatory, Chile. Radial velocity measurements are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/504/617

de Medeiros, J. R.; Setiawan, J.; Hatzes, A. P.; Pasquini, L.; Girardi, L.; Udry, S.; Döllinger, M. P.; da Silva, L.

2009-09-01

349

OUTWARD MIGRATION OF JUPITER AND SATURN IN EVOLVED GASEOUS DISKS  

SciTech Connect

The outward migration of a pair of resonant-orbit planets, driven by tidal interactions with a gas-dominated disk, is studied in the context of evolved solar nebula models. The planets' masses, M{sub 1} and M{sub 2}, correspond to those of Jupiter and Saturn. Hydrodynamical calculations in two and three dimensions are used to quantify the migration rates and analyze the conditions under which the outward migration mechanism may operate. The planets are taken to be fully formed after 10{sup 6} and before 3 Multiplication-Sign 10{sup 6} years. The orbital evolution of the planets in an evolving disk is then calculated until the disk's gas is completely dissipated. Orbital locking in the 3:2 mean motion resonance may lead to outward migration under appropriate conditions of disk viscosity and temperature. However, resonance locking does not necessarily result in outward migration. This is the case, for example, if convergent migration leads to locking in the 2:1 mean motion resonance, as post-formation disk conditions seem to suggest. Accretion of gas on the planets may deactivate the outward migration mechanism by raising the mass ratio M{sub 2}/M{sub 1} and/or by reducing the accretion rate toward the star, and hence depleting the inner disk. For migrating planets locked in the 3:2 mean motion resonance, there are stalling radii that depend on disk viscosity and on stellar irradiation, when it determines the disk's thermal balance. Planets locked in the 3:2 orbital resonance that start moving outward from within 1-2 AU may reach beyond Almost-Equal-To 5 AU only under favorable conditions. However, within the explored space of disk parameters, only a small fraction-less than a few percent-of the models predict that the interior planet reaches beyond Almost-Equal-To 4 AU.

D'Angelo, Gennaro [NASA Ames Research Center, MS 245-3, Moffett Field, CA 94035 (United States); Marzari, Francesco, E-mail: gennaro.dangelo@nasa.gov, E-mail: francesco.marzari@pd.infn.it [Department of Physics, University of Padova, Via Marzolo 8, Padova I-35131 (Italy)

2012-09-20

350

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

351

Jupiter, Tether, and Lenz's Law  

NASA Technical Reports Server (NTRS)

Jupiter has a large, complex, and intense magnetic field that is thought to arise from electrical currents in the rapidly spinning metallic hydrogen interior. The strong magnetic field can induce currents when the conductive tether is directed toward or away from Jupiter. The currents can be stored and used for both propulsion and power generation. Therefore, our spacecraft might be able to visit several Jovian moons or maintain in the orbit around Jupiter. In our future space traveling, we also can use this technical skill to travel to other planets without any fuel. First-year physics textbooks describe Lenz's Law in which current is induced in a conductor moving through a stationary magnetic field. A demonstration of induced current in a stationary conductor and moving magnetic field is described, which may have space-tether application.

Lee, Russell

1999-01-01

352

Arsine in Saturn and Jupiter  

SciTech Connect

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. 19 references.

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

1989-03-01

353

Voyager-Jupiter radio science data papers  

NASA Technical Reports Server (NTRS)

The reduction and interpretation of the radio science data from the Voyager 1 and 2 encounters of the planet Jupiter and its satellites resulted in the preparation of several papers for publication in the special Voyager-Jupiter issue of the Journal of Geophysical Research. The radio science and tracking systems of the Deep Space Network provide the data which makes this research possible. This article lists submitted papers by title, with their authors and with abstracts of their contents.

Levy, G. S.; Wood, G. E.

1980-01-01

354

Significant Science at Jupiter Using Solar Power  

NASA Technical Reports Server (NTRS)

Missions to the Outer Planets are challenging for a number of reasons, primary of which is the low output of solar arrays at large heliocentric distances. The INSIDE Jupiter mission is a Discovery concept for a science investigation at Jupiter that is capable of producing major studies of the Jovian internal structure and ionospheric-magnetospheric coupling. Additional information is contained in the original extended abstract.

Reitsema, H. J.; Smith, E. J.; Spilker, T.; Reinert, R.

2001-01-01

355

Toward Eclipse Mapping of Hot Jupiters  

Microsoft Academic Search

Recent Spitzer infrared measurements of hot-Jupiter eclipses suggest that eclipse-mapping techniques could be used to spatially resolve the dayside photospheric emission of these planets using partial occultations. As a first step in this direction, we simulate ingress\\/egress light curves for three bright eclipsing hot Jupiters and evaluate the degree to which parameterized photospheric emission models can be distinguished from each

Emily Rauscher; Kristen Menou; Sara Seager; Drake Deming; James Y.-K. Cho; Bradley M. S. Hansen

2007-01-01

356

Expected Detection and False Alarm Rates for Transiting Jovian Planets  

Microsoft Academic Search

Ground-based searches for transiting Jupiter-sized planets have so far\\u000aproduced few detections of planets, but many of stellar systems with eclipse\\u000adepths, durations, and orbital periods that resemble those expected from\\u000aplanets. I show that these detection rates are consistent with our present\\u000aknowledge of binary and multiple-star systems, and of Jovian-mass extrasolar\\u000aplanets. Upcoming space-based searches for transiting Earth-sized

Timothy M. Brown

2003-01-01

357

THE EVOLUTION OF THE SOLAR NEBULA I. EVOLUTION OF THE GLOBAL PROPERTIES AND PLANET MASSES  

SciTech Connect

We investigate the formation, structure, and evolution of the solar nebula by including nonuniform viscosity and the mass influx from the gravitational collapse of the molecular cloud core. The calculations are done by using currently accepted viscosity, which is nonuniform, and probable mass influx from star formation theory. In the calculation of the viscosity, we include the effect of magnetorotational instability. The radial distributions of the surface density and other physical quantities of the nebula are significantly different from nebula models with constant alpha viscosity and the models which do not include the mass influx. We find that the nebula starts to form from the inner boundary because of the inside-out collapse and then expands due to viscosity. The surface density is not a monotonic function of the radius like the case of uniform viscosity. There are minimums near 1.5 AU due to nonuniform viscosity. The general shape of the surface density is sustained before the mass influx stops because the mass supply offsets mass loss accreted onto the protosun and provides the mass needed for the nebula expansion. We show that not all protoplanetary disks experience gravitational instability during some periods of their lifetime. We find that the nebula becomes gravitationally unstable in some durations when the angular momentum of the cloud core is high. Our numerical calculations confirm Jin's early suggestion that nonuniform viscosity explains the differences in mass and gas content among Jovian planets. Our calculations of nebular evolution show that the nebula temperature is less than 1200 K. Even in the inner portion of the nebula, refractory material from the molecular cloud may survive and refractory condensates may form.

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

2010-02-20

358

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

359

Time-dependent modelling of mass-loading, transport, chemistry and magnetic fields in Jupiter's magnetosphere  

NASA Astrophysics Data System (ADS)

Radial profiles of plasma flux tube content are often modelled using diffusive plasma transport using an assumed source rate and diffusion coefficient. Such diffusive transport modelling can be combined with neutral-cloud theory to provide time-dependent chemistry in the plasma torus. Independently, and not necessarily self-consistently, the radial profile of the plasma azimuthal velocity can be calculated using the Hill-Pontius equation, for the mathematically separable case where the source and transport regions are spatially distinct. These steady state profiles can be imposed into a magnetospheric model to understand the resulting fields and currents. In a non-steady state where the plasma source rate is varying, and/or the outflowing plasma is not in equilibrium, these solutions do not apply. Hence, important questions concerning time-dependent variability in the jovian and saturnian magnetospheres cannot be adequately addressed using such models. In this paper we present a new approach where we solve the time-dependent equations for diffusive radial transport of both mass and angular momentum coupled with a neutral-plasma chemistry model, thus allowing for time-dependent plasma sources and the motion of radial structures produced by such time-dependence. These time-dependent solutions are coupled to an Euler potential magnetospheric model to calculate time-dependent magnetospheric configurations. We present our modelling methodology and the first results from this coupled model.

Arridge, C. S.

2013-12-01

360

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

361

Planet Impact: What's Your Angle  

NSDL National Science Digital Library

In this interactive module, students can vary the comet's angle of approach to see the effect of gravity on its trajectory towards Jupiter. The speed and masses of the two bodies are held constant. The goal is for the students to understand the relationship between the distance from the planet and the force of gravity. Students may work independently or in small groups to complete this activity. It may also be done as a teacher-directed activity in the classroom. After completing this module, students will learn about how changing the angle of approach affects the force of gravity on a comet. This module is a part of the online exploration "Planet Impact!" An explanation of the science behind the animations can be found in "Science Scoop." More information on the crash of Shoemaker-Levy 9 on Jupiter can be obtained from "Gravity Gallery" and "Comet News." Detailed teacher pages, identified as Teaching Tips on the title pages of the activity, provide science background information, lesson plan ideas, related resources, and alignment with national education standards.

362

Diversity of planetary systems in low-mass disks. Terrestrial-type planet formation and water delivery  

NASA Astrophysics Data System (ADS)

Context. Several studies, observational and theoretical, suggest that planetary systems with only rocky planets are the most common in the Universe. Aims: We study the diversity of planetary systems that might form around Sun-like stars in low-mass disks without gas-giant planets. We focus especially on the formation process of terrestrial planets in the habitable zone (HZ) and analyze their water contents with the goal to determine systems of astrobiological interest. In addition, we study the formation of planets on wide orbits because they can be detected with the microlensing technique. Methods: N-body simulations of high resolution were developed for a wide range of surface density profiles. A bimodal distribution of planetesimals and planetary embryos with different physical and orbital configurations was used to simulate the planetary accretion process. The surface density profile combines a power law for the inside of the disk of the form r-?, with an exponential decay to the outside. We performed simulations adopting a disk of 0.03 M? and values of ? = 0.5, 1 and 1.5. Results: All our simulations form planets in the HZ with different masses and final water contents depending on the three different profiles. For ? = 0.5, our simulations produce three planets in the HZ with masses ranging from 0.03 M? to 0.1 M? and water contents between 0.2 and 16 Earth oceans (1 Earth ocean =2.8 × 10-4 M?). For ? = 1, three planets form in the HZ with masses between 0.18 M? and 0.52 M? and water contents from 34 to 167 Earth oceans. Finally, for ? = 1.5, we find four planets in the HZ with masses ranging from 0.66 M? to 2.21 M? and water contents between 192 and 2326 Earth oceans. This profile shows distinctive results because it is the only one of those studied here that leads to the formation of water worlds. Conclusions: Since planetary systems with ? = 1 and 1.5 present planets in the HZ with suitable masses to retain a long-lived atmosphere and to maintain plate tectonics, they seem to be the most promising candidates to be potentially habitable. Particularly, these systems form Earths and Super-Earths of at least 3 M? around the snow line, which can be discovered by the microlensing technique.

Ronco, M. P.; de Elía, G. C.

2014-07-01

363

HIDING IN THE SHADOWS: SEARCHING FOR PLANETS IN PRE-TRANSITIONAL AND TRANSITIONAL DISKS  

SciTech Connect

Transitional and pre-transitional disks can be explained by a number of mechanisms. This work aims to find a single observationally detectable marker that would imply a planetary origin for the gap and, therefore, indirectly indicate the presence of a young planet. N-body simulations were conducted to investigate the effect of an embedded planet of one Jupiter mass on the production of instantaneous collisional dust derived from a background planetesimal disk. Our new model allows us to predict the dust distribution and resulting observable markers with greater accuracy than previous works. Dynamical influences from a planet on a circular orbit are shown to enhance dust production in the disk interior and exterior to the planet orbit, while removing planetesimals from the orbit itself, creating a clearly defined gap. In the case of an eccentric planet, the gap opened by the planet is not as clear as the circular case, but there is a detectable asymmetry in the dust disk.

Dobinson, Jack; Leinhardt, Zoë M. [School of Physics, H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL (United Kingdom)] [School of Physics, H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL (United Kingdom); Dodson-Robinson, Sarah E. [Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States)] [Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States); Teanby, Nick A. [School of Earth Sciences, Wills Memorial Building, University of Bristol, Bristol, BS8 1RJ (United Kingdom)] [School of Earth Sciences, Wills Memorial Building, University of Bristol, Bristol, BS8 1RJ (United Kingdom)

2013-11-10

364

On the Horseshoe Drag of a Low-Mass Planet. II. Migration in Adiabatic Disks  

NASA Astrophysics Data System (ADS)

We evaluate the horseshoe drag exerted on a low-mass planet embedded in a gaseous disk, assuming the disk's flow in the co-orbital region to be adiabatic. We restrict this analysis to the case of a planet on a circular orbit, and we assume a steady flow in the corotating frame. We also assume that the corotational flow upstream of the U-turns is unperturbed, so that we discard saturation effects. In addition to the classical expression for the horseshoe drag in barotropic disks, which features the vortensity gradient across corotation, we find an additional term which scales with the entropy gradient, and whose amplitude depends on the perturbed pressure at the stagnation point of the horseshoe separatrices. This additional torque is exerted by evanescent waves launched at the horseshoe separatrices, as a consequence of an asymmetry of the horseshoe region. It has a steep dependence on the potential's softening length, suggesting that the effect can be extremely strong in the three-dimensional case. We describe the main properties of the co-orbital region (the production of vortensity during the U-turns, the appearance of vorticity sheets at the downstream separatrices, and the pressure response), and we give torque expressions suitable to this regime of migration. Side results include a weak, negative feedback on migration, due to the dependence of the location of the stagnation point on the migration rate, and a mild enhancement of the vortensity-related torque at a large entropy gradient.

Masset, F. S.; Casoli, J.

2009-09-01

365

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

366

Jovian Planet Finder optical system  

NASA Astrophysics Data System (ADS)

The Jovian Planet Finder (JPF) is a proposed NASA MIDEX mission to place a highly optimized coronagraphic telescope on the International Space Station (ISS) to image Jupiter-like planets around nearby stars. The optical system is an off-axis, unobscured telescope with a 1.5 m primary mirror. A classical Lyot coronagraph with apodized occulting spots is used to reduce diffracted light from the central star. In order to provide the necessary contrast for detection of a planet, scattered light from mid-spatial-frequency errors is reduced by using super-smooth optics. Recent advances in polishing optics for extreme-ultraviolet lithography have shown that a factor of >30 reduction in midfrequency errors relative to those in the Hubble Space Telescope is possible (corresponding to a reduction in scattered light of nearly 1000x). The low level of scattered and diffracted light, together with a novel utilization of field rotation introduced by the alt-azimuth ISS telescope mounting, will provide a relatively low-cost facility for not only imaging extrasolar planets, but also circumstellar disks, host galaxies of quasars, and low-mass substellar companions such as brown dwarfs.

Krist, John E.; Clampin, Mark; Petro, Larry; Woodruff, Robert A.; Ford, Holland C.; Illingworth, Garth D.; Ftaclas, Christ

2003-02-01

367

Images of a fourth planet orbiting HR 8799.  

PubMed

High-contrast near-infrared imaging of the nearby star HR 8799 has shown three giant planets. Such images were possible because of the wide orbits (>25?astronomical units, where 1?au is the Earth-Sun distance) and youth (<100?Myr) of the imaged planets, which are still hot and bright as they radiate away gravitational energy acquired during their formation. An important area of contention in the exoplanet community is whether outer planets (>10?au) more massive than Jupiter form by way of one-step gravitational instabilities or, rather, through a two-step process involving accretion of a core followed by accumulation of a massive outer envelope composed primarily of hydrogen and helium. Here we report the presence of a fourth planet, interior to and of about the same mass as the other three. The system, with this additional planet, represents a challenge for current planet formation models as none of them can explain the in situ formation of all four planets. With its four young giant planets and known cold/warm debris belts, the HR 8799 planetary system is a unique laboratory in which to study the formation and evolution of giant planets at wide (>10?au) separations. PMID:21150902

Marois, Christian; Zuckerman, B; Konopacky, Quinn M; Macintosh, Bruce; Barman, Travis

2010-12-23

368

Formation of Planets Around the Sun and Other Stars  

ScienceCinema

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.

369

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

370

Galileo: Challenges enroute to Jupiter  

NASA Technical Reports Server (NTRS)

The Galileo spacecraft is now on its three-year direct Earth-to-Jupiter transfer trajectory. Jupiter arrived (Probe entry) is scheduled for 2:05 pm PST, December 7, 1995. The Galileo Probe will be the first human-made object to enter the atmosphere of an outer planet, while the Orbiter will be the first artificial satellite of an outer planet. A two-year Jupiter orbital mission is planned. Following launch on October 18, 1989, Galileo spent just over three years executing its Venus-Earth-Earth Gravity Assist (VEEGA) mission phase to achieve the heliocentric energy necessary to reach Jupiter. Midway through its Earth-to-Earth leg, on October 29, 1991, Galileo became the first spacecraft to encounter an asteroid. Six months earlier in April 1991, the spacecraft's high-gain antenna (HGA) failed to deploy properly. The special guidance, navigation, and control (GN&C) problems associated with a 20-month campaign of maneuvers to free the stuck antenna and successfully perform the asteroid encounter without it are described. The overall mission and spacecraft status are also reported.

O'Neil, William J.

1993-01-01

371

The Nine Planets: Mars  

NSDL National Science Digital Library

This Nine Planets page contains details about the planet Mars. Information includes planet diameter, mass, distance from the Sun, orbit, and mythology. Also covered are planet composition, surface features, atmosphere and magnetic field data, temperature on the planet, and results from exploration spacecraft. Phobos and Deimos (Mars satellites) are also covered in depth. The site provides links to more images, movies, and facts about Mars and its moons, and discusses unanswered questions about the planet.

Arnett, Bill

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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 (