scholarly journals Full exploration of the giant planet population around β Pictoris

2018 ◽  
Vol 612 ◽  
pp. A108 ◽  
Author(s):  
A.-M. Lagrange ◽  
M. Keppler ◽  
N. Meunier ◽  
J. Lannier ◽  
H. Beust ◽  
...  
Keyword(s):  
Extrasolar Planets ◽  
Giant Planet ◽  
Young Stars ◽  
Giant Planets ◽  
Close Orbit ◽  
Wide Range ◽  
Detection Probabilities ◽  
Solar Type ◽  
Formation And Evolution ◽  
The One

Context. The search for extrasolar planets has been limited so far to close orbit (typ. ≤5 au) planets around mature solar-type stars on the one hand, and to planets on wide orbits (≥10 au) around young stars on the other hand. To get a better view of the full giant planet population, we have started a survey to search for giant planets around a sample of carefully selected young stars. Aims. This paper aims at exploring the giant planet population around one of our targets, β Pictoris, over a wide range of separations. With a disk and a planet already known, the β Pictoris system is indeed a very precious system for studies of planetary formation and evolution, as well as of planet–disk interactions. Methods. We analyse more than 2000 HARPS high-resolution spectra taken over 13 years as well as NaCo images recorded between 2003 and 2016. We combine these data to compute the detection probabilities of planets throughout the disk, from a fraction of au to a few dozen au. Results. We exclude the presence of planets more massive than 3 MJup closer than 1 au and further than 10 au, with a 90% probability. 15+ MJup companions are excluded throughout the disk except between 3 and 5 au with a 90% probability. In this region, we exclude companions with masses larger than 18 (resp. 30) MJup with probabilities of 60 (resp. 90) %.

scholarly journals Direct imaging of exoplanets

2014 ◽  
Vol 372 (2014) ◽  
pp. 20130090 ◽  
Author(s):  
Anne-Marie Lagrange
Keyword(s):  
Radial Velocity ◽  
Second Generation ◽  
Giant Planet ◽  
Temporal Variations ◽  
Young Stars ◽  
Giant Planets ◽  
Direct Imaging ◽  
Formation And Evolution ◽  
Near Future ◽  
Central Stars

Most of the exoplanets known today have been discovered by indirect techniques, based on the study of the host star radial velocity or photometric temporal variations. These detections allowed the study of the planet populations in the first 5–8 AU from the central stars and have provided precious information on the way planets form and evolve at such separations. Direct imaging on 8–10 m class telescopes allows the detection of giant planets at larger separations (currently typically more than 5–10 AU) complementing the indirect techniques. So far, only a few planets have been imaged around young stars, but each of them provides an opportunity for unique dedicated studies of their orbital, physical and atmospheric properties and sometimes also on the interaction with the ‘second-generation’, debris discs. These few detections already challenge formation theories. In this paper, I present the results of direct imaging surveys obtained so far, and what they already tell us about giant planet (GP) formation and evolution. Individual and emblematic cases are detailed; they illustrate what future instruments will routinely deliver for a much larger number of stars. I also point out the limitations of this approach, as well as the needs for further work in terms of planet formation modelling. I finally present the progress expected in direct imaging in the near future, thanks in particular to forthcoming planet imagers on 8–10 m class telescopes.

scholarly journals The likelihood of detecting young giant planets with high-contrast imaging and interferometry

2019 ◽  
Vol 490 (1) ◽  
pp. 502-512 ◽  
Author(s):  
A L Wallace ◽  
M J Ireland
Keyword(s):  
Radial Velocity ◽  
Near Infrared ◽  
Giant Planet ◽  
Giant Planets ◽  
Contrast Imaging ◽  
Distribution Models ◽  
High Contrast Imaging ◽  
Solar Type ◽  
Infrared Wavelengths ◽  
Core Accretion

ABSTRACT Giant planets are expected to form at orbital radii that are relatively large compared to transit and radial velocity detections (>1 au). As a result, giant planet formation is best observed through direct imaging. By simulating the formation of giant (0.3–5MJ) planets by core accretion, we predict planet magnitude in the near-infrared (2–4 μm) and demonstrate that, once a planet reaches the runaway accretion phase, it is self-luminous and is bright enough to be detected in near-infrared wavelengths. Using planet distribution models consistent with existing radial velocity and imaging constraints, we simulate a large sample of systems with the same stellar and disc properties to determine how many planets can be detected. We find that current large (8–10 m) telescopes have at most a 0.2 per cent chance of detecting a core-accretion giant planet in the L’ band and 2 per cent in the K band for a typical solar-type star. Future instruments such as METIS and VIKiNG have higher sensitivity and are expected to detect exoplanets at a maximum rate of 2 and 8 per cent, respectively.

scholarly journals Strategic Exploration of Exoplanets and Disks with Subaru: SEEDS

2010 ◽  
Vol 6 (S276) ◽  
pp. 436-437
Author(s):  
Nobuhiko Kusakabe ◽  
Motohide Tamura ◽  
Ryo Kandori ◽  
Tomoyuki Kudo ◽  
Jun Hashimoto ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Young Stars ◽  
Giant Planets ◽  
Current Status ◽  
High Contrast ◽  
Direct Imaging ◽  
Instrument Performance ◽  
Early Results ◽  
Solar Type ◽  
Adaptive Optics System

AbstractThe purpose of the SEEDS project (PI: M. Tamura) is to conduct a direct imaging survey, searching for giant planets as well as protoplanetary/debris disks at a few to a few tens of AU regions around 500 nearby solar-type or more massive young stars with the combination of the Subaru 8.2m telescope, the new high-contrast instrument HiCIAO, and the adaptive optics system AO188. After instrument performance verification, the SEEDS survey successfully started in October 2009. We have already detected many companion candidates to be followed-up, and clear and much better detections of disks or details of known disks structures. In this contribution, we will outline our goal, current status, early results, and future instrumentation plans.

scholarly journals Enhanced Lidov–Kozai migration and the formation of the transiting giant planet WD 1856+534 b

2020 ◽  
Vol 501 (1) ◽  
pp. 507-514 ◽  
Author(s):  
Christopher E O’Connor ◽  
Bin Liu ◽  
Dong Lai
Keyword(s):  
Main Sequence ◽  
Semimajor Axis ◽  
Giant Planet ◽  
Giant Planets ◽  
Occurrence Rate ◽  
M Dwarfs ◽  
High Eccentricity ◽  
Absolute Limit ◽  
Short Period ◽  
Wide Range

ABSTRACT We investigate the possible origin of the transiting giant planet WD 1856+534 b, the first strong exoplanet candidate orbiting a white dwarf, through high-eccentricity migration (HEM) driven by the Lidov–Kozai (LK) effect. The host system’s overall architecture is a hierarchical quadruple in the ‘2 + 2’ configuration, owing to the presence of a tertiary companion system of two M-dwarfs. We show that a secular inclination resonance in 2 + 2 systems can significantly broaden the LK window for extreme eccentricity excitation (e ≳ 0.999), allowing the giant planet to migrate for a wide range of initial orbital inclinations. Octupole effects can also contribute to the broadening of this ‘extreme’ LK window. By requiring that perturbations from the companion stars be able to overcome short-range forces and excite the planet’s eccentricity to e ≃ 1, we obtain an absolute limit of $a_{1} \gtrsim 8 \, \mathrm{au}\, (a_{3} / 1500 \, \mathrm{au})^{6/7}$ for the planet’s semimajor axis just before migration (where a3 is the semimajor axis of the ‘outer’ orbit). We suggest that, to achieve a wide LK window through the 2 + 2 resonance, WD 1856 b likely migrated from $30 \, \mathrm{au}\lesssim a_{1} \lesssim 60 \, \mathrm{au}$, corresponding to ∼10–$20 \, \mathrm{au}$ during the host’s main-sequence phase. We discuss possible difficulties of all flavours of HEM affecting the occurrence rate of short-period giant planets around white dwarfs.

scholarly journals Eccentricity Dependence on Iron Abundance

2013 ◽  
Vol 8 (S299) ◽  
pp. 397-398
Author(s):  
Stuart F. Taylor
Keyword(s):  
Giant Planet ◽  
Major Product ◽  
Giant Planets ◽  
Disk Accretion ◽  
Period Range ◽  
Architectural Features ◽  
Initial Iron ◽  
Iron Abundance ◽  
Formation And Evolution ◽  
Planet Accretion

AbstractThe occurrence and eccentricity distribution of planets as a function of period is significantly different for iron-rich and iron-poor planet systems. We find that iron-poor stars with planets having periods between 525 and 600 days have higher eccentricity than such systems outside this range. If whole planet pollution causes the correlation of giant planet eccentricity with stellar iron abundance, then this cluster could be due to a paucity of pollution in this period range. Newly reported patterns of planet occurrence must result from planet system architectural features such as the snow line, followed by subsequent migration. Different results favor pollution or higher initial iron abundance causing the higher occurrence fraction of giant planets hosted by iron-rich stars, but the two explanations could be complementary. Relations between planet and stellar parameters are a major product of planet-finding, which promise further insights into star-planet system formation and evolution. Collaborators are sought to study these patterns. We expect a spirited debate over the relative contributions of initial abundances, disk accretion, and whole planet accretion.

New models of Jupiter in the context of Juno and Galileo: signature of a decoupling between the atmosphere and the interior

2020 ◽  
Author(s):  
Florian Debras ◽  
Gilles Chabrier
Keyword(s):  
Extrasolar Planets ◽  
Convective Zone ◽  
Giant Planets ◽  
Atmospheric Composition ◽  
Observational Constraints ◽  
Physical Processes ◽  
Hot Jupiters ◽  
Formation And Evolution ◽  
Gas Accretion

<p><span lang="en-US">Juno's observations of Jupiter's gravity field have revealed extremely low values for the gravitational moments that are difficult to reconcile with the high abundance of metals observed in the atmosphere by Galileo. Recent studies chose to arbitrarily get rid of one of these two constraints in order to build models of Jupiter.</span></p> <p><span lang="en-US">In this presentation, I will detail our new Jupiter structure models reconciling Juno and Galileo observational constraints. These models confirm the need to separate Jupiter into at least 4 layers: an outer convective shell, a non-convective zone of compositional change, an inner convective shell and a diluted core representing about 60 percent of the planet in radius. Compared to other studies, these models propose a new idea with important consequences: a decrease in the quantity of metals between the outer and inner convective shells. This would imply that the atmospheric composition is not representative of the internal composition of the planet, contrary to what is regularly admitted, and would strongly impact the Jupiter formation scenarios (localization, migration, accretion).</span></p> <p><span lang="en-US">In particular, the presence of an internal non-convective zone prevents mixing between the two convective envelopes. I will detail the physical processes of this semi-convective zone (layered convection or H-He immiscibility) and explain how they may persist during the evolution of the planet.</span></p> <p><span lang="en-US">These models also impose a limit mass on the compact core, which cannot be heavier than 5 Earth masses. Such a mass, lower than the runaway gas accretion minimum mass, needs to be explained in the light of our understanding of the formation and evolution of giant planets.</span></p> <p><span lang="en-US">Using these models of Jupiter, I will finally detail the application of our new understanding of the interior of this planet to giant exoplanets. At a time of direct imaging of extrasolar planets and atmospheric characterization of hot Jupiters, a good understanding of the internal processes of planets in the solar system is paramount to make the best use of all the observations.</span></p>

scholarly journals Scenarios of giant planet formation and evolution and their impact on the formation of habitable terrestrial planets

2014 ◽  
Vol 372 (2014) ◽  
pp. 20130072 ◽  
Author(s):  
Alessandro Morbidelli
Keyword(s):  
Solar System ◽  
Giant Planet ◽  
Giant Planets ◽  
Terrestrial Planets ◽  
Evolutionary Patterns ◽  
Eccentric Orbits ◽  
Earth Like Planets ◽  
Large Eccentricity ◽  
Formation And Evolution ◽  
Orbital Instability

In our Solar System, there is a clear divide between the terrestrial and giant planets. These two categories of planets formed and evolved separately, almost in isolation from each other. This was possible because Jupiter avoided migrating into the inner Solar System, most probably due to the presence of Saturn, and never acquired a large-eccentricity orbit, even during the phase of orbital instability that the giant planets most likely experienced. Thus, the Earth formed on a time scale of several tens of millions of years, by collision of Moon- to Mars-mass planetary embryos, in a gas-free and volatile-depleted environment. We do not expect, however, that this clear cleavage between the giant and terrestrial planets is generic. In many extrasolar planetary systems discovered to date, the giant planets migrated into the vicinity of the parent star and/or acquired eccentric orbits. In this way, the evolution and destiny of the giant and terrestrial planets become intimately linked. This paper discusses several evolutionary patterns for the giant planets, with an emphasis on the consequences for the formation and survival of habitable terrestrial planets. The conclusion is that we should not expect Earth-like planets to be typical in terms of physical and orbital properties and accretion history. Most habitable worlds are probably different, exotic worlds.

scholarly journals SEEDS: Strategic Explorations of Exoplanets and Disks with Subaru

2013 ◽  
Vol 8 (S299) ◽  
pp. 12-16
Author(s):  
Motohide Tamura ◽  
Keyword(s):  
Massive Star ◽  
Protoplanetary Disks ◽  
Young Stars ◽  
Giant Planets ◽  
Debris Disks ◽  
High Contrast ◽  
Direct Imaging ◽  
Solar Type ◽  
Strategic Program

AbstractSEEDS is the first Subaru Strategic Program, whose aim is to conduct a direct imaging survey for giant planets as well as protoplanetary/debris disks at a few to a few tens of AU region around 500 nearby solar-type or more massive young stars devoting 120 Subaru nights for 5 years. The targets are composed of five categories spanning the ages of ~1 Myr to ~1 Gyr. Some RV-planet targets with older ages are also observed. The survey employs the new high-contrast instrument HiCIAO, a successor of the previous NIR coronagraph camera CIAO for the Subaru Telescope. We describe the outline of this survey and present its first three years of results. The survey has published ~20 refereed papers by now. The main results are as follows: (1) detection and characterization of the most unequivocal and lowest-mass planet via direct imaging. (2) detection of a super-Jupiter around the most massive star ever imaged, (3) detection of companions around a retrograde exoplanet system, which supports the Kozai mechanism for the origin of retrograde orbit (not in this proceedings, but see Narita et al. 2010, 2012). We also report (4) the discovery of unprecedentedly detailed structures of more than a dozen of protoplanetary disks and some debris disks. The detected structures such as wide gaps and spirals arms of a Solar-system scale could be signpost of planet.

scholarly journals VINCI/VLTI Observations of Main Sequence Stars

2004 ◽  
Vol 219 ◽  
pp. 80-84
Author(s):  
Pierre Kervella ◽  
Frédéric Thévenin ◽  
Pierre Morel ◽  
Janine Provost ◽  
Gabrielle Berthomieu ◽  
...  
Keyword(s):  
Main Sequence ◽  
Extrasolar Planets ◽  
Physical Processes ◽  
Main Sequence Stars ◽  
M Dwarfs ◽  
The Past ◽  
Wide Range ◽  
Solar Type ◽  
The Universe ◽  
Angular Diameters

Main Sequence (MS) stars are by far the most numerous class in the Universe. They are often somewhat neglected as they are relatively quiet objects (but exceptions exist), though they bear testimony of the past and future of our Sun. An important characteristic of the MS stars, particularly the solar-type ones, is that they host the large majority of the known extrasolar planets. Moreover, at the bottom of the MS, the red M dwarfs pave the way to understanding the physics of brown dwarfs and giant planets. We have measured very precise angular diameters from recent VINCI/VLTI interferometric observations of a number of MS stars in the K band, with spectral types between A1V and M5.5V. They already cover a wide range of effective temperatures and radii. Combined with precise Hipparcos parallaxes, photometry, spectroscopy as well as the asteroseismic information available for some of these stars, the angular diameters put strong constraints on the detailed models of these stars, and therefore on the physical processes at play.

scholarly journals The Obliquity of HIP 67522 b: A 17 Myr Old Transiting Hot, Jupiter-sized Planet

2021 ◽  
Vol 922 (1) ◽  
pp. L1
Author(s):  
Alexis Heitzmann ◽  
George Zhou ◽  
Samuel N. Quinn ◽  
Stephen C. Marsden ◽  
Duncan Wright ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Planet Formation ◽  
Giant Planet ◽  
Young Stars ◽  
Global Model ◽  
High Eccentricity ◽  
A Value ◽  
Special Place ◽  
Migration History ◽  
Formation And Evolution

Abstract HIP 67522 b is a 17 Myr old, close-in (P orb = 6.96 days), Jupiter-sized (R = 10 R ⊕) transiting planet orbiting a Sun-like star in the Sco–Cen OB association. We present our measurement of the system’s projected orbital obliquity via two spectroscopic transit observations using the CHIRON spectroscopic facility. We present a global model that accounts for large surface brightness features typical of such young stars during spectroscopic transit observations. With a value of ∣ λ ∣ = 5.8 − 5.7 + 2.8 ° it is unlikely that this well-aligned system is the result of a high-eccentricity-driven migration history. By being the youngest planet with a known obliquity, HIP 67522 b holds a special place in contributing to our understanding of giant planet formation and evolution. Our analysis shows the feasibility of such measurements for young and very active stars.

Sign in / Sign up

Export Citation Format

Share Document