The Distant Satellites of Uranus and the Other Giant Planets

2006 ◽  
pp. 187-192 ◽  
Author(s):  
Brian G. Marsden ◽  
Gareth V. Williams ◽  
Kaare Aksnes
Keyword(s):  
Giant Planets ◽  
The Other

scholarly journals Jupiter and the other Giants: A Comparative Study

2010 ◽  
Vol 6 (S269) ◽  
pp. 155-164
Author(s):  
Thérèse Encrenaz
Keyword(s):  
Comparative Study ◽  
Ring System ◽  
Atmospheric Dynamics ◽  
Giant Planets ◽  
The Other ◽  
The Sun ◽  
Origin And Evolution ◽  
Open Questions ◽  
Internal Structures ◽  
Pioneer 10

AbstractThe four giant planets - Jupiter, Saturn, Uranus and Neptune - have common properties which make them very different from the terrestrial planets: located at large distances from the Sun, they have big sizes and masses but low densities; they all have a ring system and a large number of satellites. These common properties can be understood in the light of their formation scenario, based upon the accretion of protosolar gas on an initial icy core. Giant planets have been explored by space missions (Pioneer 10 and 11, Voyager 1 and 2, Galileo and Cassini) but also by Earth-orbiting satellites and ground-based telescopes. There are still open questions related to the origin and evolution of the giant planets, in particular their moderate migration, the origin of the cold planetesimals which formed Jupiter, the origin of the atmospheric dynamics in Jupiter and Saturn, and the differences in the internal structures of Uranus and Neptune.

scholarly journals Probing the impact of stellar duplicity on the frequency of giant planets: Final results of our VLT/NACO survey

2010 ◽  
Vol 6 (S276) ◽  
pp. 409-410 ◽  
Author(s):  
Anne Eggenberger ◽  
Stéphane Udry ◽  
Gaël Chauvin ◽  
Thierry Forveille ◽  
Jean-Luc Beuzit ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Proper Motion ◽  
Binary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
The Other ◽  
Physical Association ◽  
Short Period ◽  
Solar Type ◽  
The Impact

AbstractIf it is commonly agreed that the presence of a (moderately) close stellar companion affects the formation and the dynamical evolution of giant planets, the frequency of giant planets residing in binary systems separated by less than 100 AU is unknown. To address this issue, we have conducted with VLT/NACO a systematic adaptive optics search for moderately close stellar companions to 130 nearby solar-type stars. According to the data from Doppler surveys, half of our targets host at least one planetary companion, while the other half show no evidence for short-period giant planets. We present here the final results of our survey, which include a new series of second-epoch measurements to test for common proper motion. The new observations confirm the physical association of two companion candidates and prove the unbound status of many others. These results strengthen our former conclusion that circumstellar giant planets are slightly less frequent in binaries with mean semimajor axes between 35 and 100 AU than in wider systems or around single stars.

scholarly journals Jovian seismology

1994 ◽  
Vol 147 ◽  
pp. 481-511
Author(s):  
Benoît Mosser
Keyword(s):  
High Pressure ◽  
Internal Structure ◽  
Low Temperatures ◽  
High Pressures ◽  
Giant Planets ◽  
The Other ◽  
Interior Structure ◽  
Theoretical Approaches ◽  
Thermodynamical Laws ◽  
The Relationship

AbstractThis paper reviews a new astrophysical subject: seismology of the giant planets. Seismology is dedicated to the sounding of the interior structure of any object; on the other hand, the interiors of the Jovian planets need to be constrained, in order to improve our knowledge of their structure and of their evolution, as well as the thermodynamical laws involved at high pressures and low temperatures. The relationship between Jovian seismology and, first, Jovian internal structure, and second, high pressure physics, is examined, in order to determine the task of “dioseismology”† in the next years. We present then the seismological theoretical approaches developped since the pionnering work of Vorontsov et al. (1976), who calculated the frequencies of the Jovian eigenmodes. We report the first observational attempts for the detection of the oscillations of Jupiter. We discuss the observational results and examine what can be done in the future.

scholarly journals Geophysical evidence that Saturn’s Moon Phoebe originated from a C-type asteroid reservoir

2019 ◽  
Vol 486 (1) ◽  
pp. 538-543 ◽  
Author(s):  
Julie Castillo-Rogez ◽  
Pierre Vernazza ◽  
Kevin Walsh
Keyword(s):  
Thermal Evolution ◽  
Kuiper Belt ◽  
Size Class ◽  
Giant Planets ◽  
The Other ◽  
The Sun ◽  
Dynamical Models ◽  
Trojan Asteroids ◽  
Bulk Porosity ◽  
Internal Evolution

ABSTRACT Saturn’s Moon Phoebe has been suggested to originate from the Kuiper Belt. However, its density is twice that of Kuiper Belt objects (KBOs) in the same size class, which challenges that relationship. Since the internal evolution of mid-sized planetesimals (100–300 km in diameter) is primarily driven by the amount of accreted short-lived radioisotopes, it is possible to constrain the relative times of formation of these bodies based on their bulk porosity content, hence their densities. From modelling the thermal evolution of KBOs, we infer a difference in formation timing between these bodies and Phoebe. This confirms prior suggestions for a delayed accretion timeframe with increasing distance from the Sun. This geophysical finding combined with spectral observations suggests Phoebe formed in the same region as C-type asteroids and support recent dynamical models for a C-type body reservoir between the orbits of the giant planets. On the other hand, the similarly low densities of mid-sized D-type asteroids, Trojan asteroids, and KBOs add to the growing evidence that these objects shared a common reservoir near or beyond the orbit of Neptune and were heat starved overall.

scholarly journals Mass-Metallicity Trends in Transiting Exoplanets from Atmospheric Abundances of H2O, Na, and K

2020 ◽  
Author(s):  
Luis Welbanks ◽  
Nikku Madhusudhan ◽  
Nicole F. Allard ◽  
Ivan Hubeny ◽  
Fernand Spiegelman ◽  
...  
Keyword(s):  
Solar System ◽  
Free Parameter ◽  
Giant Planets ◽  
The Other ◽  
Formation Mechanisms ◽  
Transmission Spectra ◽  
Low Oxygen ◽  
Hot Jupiters ◽  
Hot Gas ◽  
And Migration

<p>Atmospheric compositions can provide powerful diagnostics of formation and migration histories of planetary systems. In this talk, I will present the results of our latest survey of atmospheric compositions focused on atmospheric abundances of H<sub>2</sub>O, Na, and K. We employ a sample of 19 exoplanets spanning from cool mini-Neptunes to hot Jupiters, with equilibrium temperatures between ~300 and 2700 K. We employ the latest transmission spectra, new H<sub>2</sub> broadened opacities of Na and K, and homogeneous Bayesian retrievals. We confirm detections of H<sub>2</sub>O in 14 planets and detections of Na and K in 6 planets each. Among our sample, we find a mass-metallicity trend of increasing H<sub>2</sub>O abundances with decreasing mass, spanning generally substellar values for gas giants and stellar/superstellar for Neptunes and mini-Neptunes. However, the overall trend in H<sub>2</sub>O abundances, is significantly lower than the mass-metallicity relation for carbon in the solar system giant planets and similar predictions for exoplanets. On the other hand, the Na and K abundances for the gas giants are stellar or superstellar, consistent with each other, and generally consistent with the solar system metallicity trend. The H<sub>2</sub>O abundances in hot gas giants are likely due to low oxygen abundances relative to other elements rather than low overall metallicities, and provide new constraints on their formation mechanisms. Our results show that the differing trends in the abundances of species argue against the use of chemical equilibrium models with metallicity as one free parameter in atmospheric retrievals, as different elements can be differently enhanced.</p>

4. The moons of giant planets

2015 ◽  
pp. 60-84
Author(s):  
David A. Rothery
Keyword(s):  
Space Missions ◽  
Giant Planets ◽  
The Other ◽  
Irregular Satellites ◽  
Orbital Resonance ◽  
Different Types ◽  
Tidal Heating

The giant planets Jupiter, Saturn, Uranus, and Neptune each have an extensive entourage of moons: small inner moonlets, closest to the planets, mostly less than a few tens of kilometres in radius and irregular in shape; next are large regular satellites exceeding about 200 km in radius; and then there are the irregular satellites mostly less than a few tens of kilometres in radius. ‘The moons of giant planets’ describes these different types of moons, the space missions to find them, their orbital resonance and tidal heating, as well as the spectacular and complex rings and shepherd moons of Saturn and the other giant planets.

scholarly journals Li and Be Depletion in Stars with Exoplanets?

2011 ◽  
Vol 7 (S282) ◽  
pp. 466-467
Author(s):  
E. Delgado Mena ◽  
G. Israelian ◽  
J. I. González Hernández ◽  
R. Rebolo ◽  
N. C. Santos ◽  
...  
Keyword(s):  
Planetary Systems ◽  
Giant Planets ◽  
The Other ◽  
Light Elements ◽  
Other Hand ◽  
Wide Range ◽  
Solar Type ◽  
Effective Temperatures ◽  
Host Stars

AbstractIt is well known that stars with orbiting giant planets have a higher metallic content than stars without detected planets. In addition, we have found that solar-type stars with planets present an extra Li depletion when compared with field stars. On the other hand, Be needs a greater temperature to be destroyed, so we may find such a relation in cooler stars, whose convective envelopes are deep enough to carry material to layers where Be can be burned. We present Li and Be abundances for an extensive sample of stars with and without detected planets, covering a wide range of effective temperatures (4700-6500 K) with the aim of studying possible differences between the abundances of both groups. The processes that take place in the formation of planetary systems may affect the mixing of material inside their host stars and hence the abundances of light elements.

scholarly journals Pebbles versus planetesimals

2020 ◽  
Vol 640 ◽  
pp. A21 ◽  
Author(s):  
N. Brügger ◽  
R. Burn ◽  
G. A. L. Coleman ◽  
Y. Alibert ◽  
W. Benz
Keyword(s):  
Planet Formation ◽  
Initial Conditions ◽  
Giant Planet ◽  
Mass Range ◽  
Giant Planets ◽  
The Other ◽  
Type I ◽  
Core Mass ◽  
Accretion Model ◽  
The Impact

Context. In the core accretion scenario of giant planet formation, a massive core forms first and then accretes a gaseous envelope. In the discussion of how this core forms, some divergences appear. The first scenarios of planet formation predict the accretion of kilometre-sized bodies called planetesimals, while more recent works suggest growth by the accretion of pebbles, which are centimetre-sized objects. Aims. These two accretion models are often discussed separately and our aim here is to compare the outcomes of the two models with identical initial conditions. Methods. The comparison is done using two distinct codes, one that computes the planetesimal accretion and the other the pebble accretion. All the other components of the simulated planet growth are computed identically in the two models: the disc, the accretion of gas, and the migration. Using a population synthesis approach, we compare planet simulations and study the impact of the two solid accretion models, focusing on the formation of single planets. Results. We find that the outcomes of the populations are strongly influenced by the accretion model. The planetesimal model predicts the formation of more giant planets, while the pebble accretion model forms more super-Earth-mass planets. This is due to the pebble isolation mass (Miso) concept, which prevents planets formed by pebble accretion to accrete gas efficiently before reaching Miso. This translates into a population of planets that are not heavy enough to accrete a consequent envelope, but that are in a mass range where type I migration is very efficient. We also find higher gas mass fractions for a given core mass for the pebble model compared to the planetesimal model, caused by luminosity differences. This also implies planets with lower densities, which could be confirmed observationally. Conclusions. We conclude that the two models produce different outputs. Focusing on giant planets, the sensitivity of their formation differs: for the pebble accretion model, the time at which the embryos are formed and the period over which solids are accreted strongly impact the results, while the population of giant planets formed by planetesimal accretion depends on the planetesimal size and on the splitting in the amount of solids available to form planetesimals.

scholarly journals The properties of super-Earth atmospheres

2010 ◽  
Vol 6 (S276) ◽  
pp. 212-217 ◽  
Author(s):  
Eliza M. R. Kempton
Keyword(s):  
Solar System ◽  
Bulk Composition ◽  
Theoretical Work ◽  
Giant Planets ◽  
The Other ◽  
Terrestrial Planets ◽  
Earth Atmosphere ◽  
Intermediate Mass ◽  
Rocky Planets

AbstractExtrasolar super-Earths likely have a far greater diversity in their atmospheric properties than giant planets. Super-Earths (planets with masses between 1 and 10 M⊕) lie in an intermediate mass regime between gas/ice giants like Neptune and rocky terrestrial planets like Earth and Venus. While some super-Earths (especially the more massive ones) may retain large amounts of hydrogen either from accretion processes or subsequent surface outgassing, other super-Earths should have atmospheres composed of predominantly heavier molecules, similar to the atmospheres of the rocky planets and moons of our Solar System. Others still may be entirely stripped of their atmospheres and remain as bare rocky cores. Of the two currently known transiting super-Earths one (GJ 1214b) likely falls into the former category with a thick atmosphere, while the other (CoRoT-7b) falls into the latter category with a very thin or nonexistent atmosphere. I review some of the theoretical work on super-Earth atmospheres, and I present methods for determining the bulk composition of a super-Earth atmosphere.

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