scholarly journals Chemical fingerprints of hot Jupiter planet formation

2018 ◽  
Vol 612 ◽  
pp. A93 ◽  
Author(s):  
J. Maldonado ◽  
E. Villaver ◽  
C. Eiroa
Keyword(s):  
Planet Formation ◽  
Statistical Tests ◽  
Giant Planets ◽  
Volatile Elements ◽  
Hot Jupiters ◽  
Chemical Fingerprints ◽  
Gas Giant ◽  
Orbital Periods ◽  
And Migration

Context. The current paradigm to explain the presence of Jupiter-like planets with small orbital periods (P < 10 days; hot Jupiters), which involves their formation beyond the snow line following inward migration, has been challenged by recent works that explore the possibility of in situ formation. Aims. We aim to test whether stars harbouring hot Jupiters and stars with more distant gas-giant planets show any chemical peculiarity that could be related to different formation processes. Methods. Our methodology is based on the analysis of high-resolution échelle spectra. Stellar parameters and abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn for a sample of 88 planet hosts are derived. The sample is divided into stars hosting hot (a < 0.1 au) and cool (a > 0.1 au) Jupiter-like planets. The metallicity and abundance trends of the two sub-samples are compared and set in the context of current models of planet formation and migration. Results. Our results show that stars with hot Jupiters have higher metallicities than stars with cool distant gas-giant planets in the metallicity range +0.00/+0.20 dex. The data also shows a tendency of stars with cool Jupiters to show larger abundances of α elements. No abundance differences between stars with cool and hot Jupiters are found when considering iron peak, volatile elements or the C/O, and Mg/Si ratios. The corresponding p-values from the statistical tests comparing the cumulative distributions of cool and hot planet hosts are 0.20, <0.01, 0.81, and 0.16 for metallicity, α, iron-peak, and volatile elements, respectively. We confirm previous works suggesting that more distant planets show higher planetary masses as well as larger eccentricities. We note differences in age and spectral type between the hot and cool planet host samples that might affect the abundance comparison. Conclusions. The differences in the distribution of planetary mass, period, eccentricity, and stellar host metallicity suggest a different formation mechanism for hot and cool Jupiters. The slightly larger α abundances found in stars harbouring cool Jupiters might compensate their lower metallicities allowing the formation of gas-giant planets.

scholarly journals Investigating the planet–metallicity correlation for hot Jupiters

2019 ◽  
Vol 491 (3) ◽  
pp. 4481-4487
Author(s):  
Ares Osborn ◽  
Daniel Bayliss
Keyword(s):  
Radial Velocity ◽  
Giant Planet ◽  
Giant Planets ◽  
Similar Process ◽  
Wide Field ◽  
Hot Jupiters ◽  
Galaxy Model ◽  
Gas Giant ◽  
Correlation Consistent

ABSTRACT We investigate the giant planet–metallicity correlation for a homogeneous, unbiased set of 217 hot Jupiters taken from nearly 15 yr of wide-field ground-based surveys. We compare the host star metallicity to that of field stars using the Besançon Galaxy model, allowing for a metallicity measurement offset between the two sets. We find that hot Jupiters preferentially orbit metal-rich stars. However, we find the correlation consistent, though marginally weaker, for hot Jupiters ($\beta =0.71^{+0.56}_{-0.34}$) than it is for other longer period gas giant planets from radial velocity surveys. This suggests that the population of hot Jupiters probably formed in a similar process to other gas giant planets, and differ only in their migration histories.

scholarly journals FRIENDS OF HOT JUPITERS. I. A RADIAL VELOCITY SEARCH FOR MASSIVE, LONG-PERIOD COMPANIONS TO CLOSE-IN GAS GIANT PLANETS

2014 ◽  
Vol 785 (2) ◽  
pp. 126 ◽  
Author(s):  
Heather A. Knutson ◽  
Benjamin J. Fulton ◽  
Benjamin T. Montet ◽  
Melodie Kao ◽  
Henry Ngo ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Giant Planets ◽  
Hot Jupiters ◽  
Long Period ◽  
Gas Giant

scholarly journals Constraining Planetary Migration Mechanisms in Systems of Giant Planets

2013 ◽  
Vol 8 (S299) ◽  
pp. 386-390
Author(s):  
Rebekah I. Dawson ◽  
Ruth A. Murray-Clay ◽  
John Asher Johnson
Keyword(s):  
Giant Planet ◽  
Giant Planets ◽  
Tidal Dissipation ◽  
Hot Jupiters ◽  
Short Period ◽  
Pile Up ◽  
Planetary Migration ◽  
Multi Body ◽  
Host Stars

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

scholarly journals The Rossiter-McLaughlin effect for exoplanets

2010 ◽  
Vol 6 (S276) ◽  
pp. 230-237
Author(s):  
Joshua N. Winn
Keyword(s):  
Measurement Technique ◽  
Planet Formation ◽  
Hot Jupiters ◽  
Transiting Planets ◽  
History Of ◽  
And Migration

AbstractThere are now more than 35 stars with transiting planets for which the stellar obliquity—or more precisely its sky projection—has been measured, via the eponymous effect of Rossiter and McLaughlin. The history of these measurements is intriguing. For 8 years a case was gradually building that the orbits of hot Jupiters are always well-aligned with the rotation of their parent stars. Then in a sudden reversal, many misaligned systems were found, and it now seems that even retrograde systems are not uncommon. I review the measurement technique underlying these discoveries, the patterns that have emerged from the data, and the implications for theories of planet formation and migration.

scholarly journals Planetary system formation in thermally evolving viscous protoplanetary discs

2014 ◽  
Vol 372 (2014) ◽  
pp. 20130074 ◽  
Author(s):  
Richard P. Nelson ◽  
Phil Hellary ◽  
Stephen M. Fendyke ◽  
Gavin Coleman
Keyword(s):  
Extrasolar Planets ◽  
Planetary System ◽  
Model Development ◽  
Central Star ◽  
Giant Planets ◽  
Formation Processes ◽  
Intermediate Mass ◽  
Simulation Results ◽  
Orbital Periods ◽  
And Migration

Observations of extrasolar planets are providing new opportunities for furthering our understanding of planetary formation processes. In this paper, we review planet formation and migration scenarios and describe some recent simulations that combine planetary accretion and gas-disc-driven migration. While the simulations are successful at forming populations of low- and intermediate-mass planets with short orbital periods, similar to those that are being observed by ground- and space-based surveys, our models fail to form any gas giant planets that survive migration into the central star. The simulation results are contrasted with observations, and areas of future model development are discussed.

scholarly journals Observational tests of planet formation models

2007 ◽  
Vol 3 (S249) ◽  
pp. 261-262
Author(s):  
A. Sozzetti ◽  
D. W. Latham ◽  
G. Torres ◽  
B. W. Carney ◽  
J. B. Laird ◽  
...  
Keyword(s):  
Planet Formation ◽  
Giant Planets ◽  
Evolutionary Models ◽  
Gas Giant

AbstractWe summarize the results of two experiments to address important issues related to the correlation between planet frequencies and properties and the metallicity of the hosts. Our results can usefully inform formation, structural, and evolutionary models of gas giant planets.

scholarly journals Spectral Analysis of Stars on Planet-Search Surveys

2004 ◽  
Vol 219 ◽  
pp. 29-40 ◽  
Author(s):  
Debra Fischer ◽  
Jeff A. Valenti ◽  
Geoff Marcy
Keyword(s):  
Main Sequence ◽  
Spectroscopic Analysis ◽  
Underlying Mechanism ◽  
Convective Zone ◽  
Giant Planets ◽  
Occurrence Rate ◽  
Initial Condition ◽  
Solar Metallicity ◽  
Gas Giant ◽  
Orbital Periods

We present spectroscopic analysis of ∼1000 stars on the Lick, Keck and AAT planet search projects. This analysis provides a quantitative, and unbiased correlation between metallicity and the rate of occurrence of detected gas giant planets with orbital periods shorter than three years. As stellar metallicity increases, the occurrence of planets increases. Stars with [Fe/H] that is one third of solar only have gas giants detected ∼ 3% of the time. Stars with solar metallicity have a planet occurrence rate of 5 − 10%. The occurrence of gas giant planets rises to 20% in stars with a metallicity that is three times solar.At issue is whether the quantitative dependence of planet occurrence on metallicity is primarily an initial condition, or a by-product of accretion of gas-depleted material onto the convective zone of the star. Accretion could be distinguished as the underlying mechanism for enhanced metallicity if: 1) planet-bearing F-type stars with thinner convective envelopes show a higher mean metallicity than planet-bearing G- or K-type stars, or 2) planet-bearing sub-giants with diluted convective zones showed statistically lower metallicity than their main sequence counterparts.

scholarly journals Formation of hot Jupiters through secular chaos and dynamical tides

2019 ◽  
Vol 486 (2) ◽  
pp. 2265-2280 ◽  
Author(s):  
Jean Teyssandier ◽  
Dong Lai ◽  
Michelle Vick
Keyword(s):  
Semimajor Axis ◽  
Giant Planet ◽  
Giant Planets ◽  
Orbital Energy ◽  
High Eccentricity ◽  
Hot Jupiters ◽  
Orbital Decay ◽  
Short Period ◽  
Orbital Periods ◽  
Hot Jupiter

Abstract The population of giant planets on short-period orbits can potentially be explained by some flavours of high-eccentricity migration. In this paper, we investigate one such mechanism involving ‘secular chaos’, in which secular interactions between at least three giant planets push the inner planet to a highly eccentric orbit, followed by tidal circularization and orbital decay. In addition to the equilibrium tidal friction, we incorporate dissipation due to dynamical tides that are excited inside the giant planet. Using the method of Gaussian rings to account for planet–planet interactions, we explore the conditions for extreme eccentricity excitation via secular chaos and the properties of hot Jupiters formed in this migration channel. Our calculations show that once the inner planet reaches a sufficiently large eccentricity, dynamical tides quickly dissipate the orbital energy, producing an eccentric warm Jupiter, which then decays in semimajor axis through equilibrium tides to become a hot Jupiter. Dynamical tides help the planet avoid tidal disruption, increasing the chance of forming a hot Jupiter, although not all planets survive the process. We find that the final orbital periods generally lie in the range of 2–3 d, somewhat shorter than those of the observed hot Jupiter population. We couple the planet migration to the stellar spin evolution to predict the final spin-orbit misalignments. The distribution of the misalignment angles we obtain shows a lack of retrograde orbits compared to observations. Our results suggest that high-eccentricity migration via secular chaos can only account for a fraction of the observed hot Jupiter population.

scholarly journals THE IN SITU FORMATION OF GIANT PLANETS AT SHORT ORBITAL PERIODS

2016 ◽  
Vol 817 (2) ◽  
pp. L17 ◽  
Author(s):  
A. C. Boley ◽  
A. P. Granados Contreras ◽  
B. Gladman
Keyword(s):  
Giant Planets ◽  
In Situ Formation ◽  
Orbital Periods
Sign in / Sign up

Export Citation Format

Share Document