Why Do Hydrogen and Helium Migrate from Some Planets and Smaller
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Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
An Upper Boundary in the Mass-Metallicity Plane of Exo-Neptunes
MNRAS 000, 1{8 (2016) Preprint 8 November 2018 Compiled using MNRAS LATEX style file v3.0 An upper boundary in the mass-metallicity plane of exo-Neptunes Bastien Courcol,1? Fran¸cois Bouchy,1 and Magali Deleuil1 1Aix Marseille University, CNRS, Laboratoire d'Astrophysique de Marseille UMR 7326, 13388 Marseille cedex 13, France Accepted XXX. Received YYY; in original form ZZZ ABSTRACT With the progress of detection techniques, the number of low-mass and small-size exo- planets is increasing rapidly. However their characteristics and formation mechanisms are not yet fully understood. The metallicity of the host star is a critical parameter in such processes and can impact the occurence rate or physical properties of these plan- ets. While a frequency-metallicity correlation has been found for giant planets, this is still an ongoing debate for their smaller counterparts. Using the published parameters of a sample of 157 exoplanets lighter than 40 M⊕, we explore the mass-metallicity space of Neptunes and Super-Earths. We show the existence of a maximal mass that increases with metallicity, that also depends on the period of these planets. This seems to favor in situ formation or alternatively a metallicity-driven migration mechanism. It also suggests that the frequency of Neptunes (between 10 and 40 M⊕) is, like giant planets, correlated with the host star metallicity, whereas no correlation is found for Super-Earths (<10 M⊕). Key words: Planetary Systems, planets and satellites: terrestrial planets { Plan- etary Systems, methods: statistical { Astronomical instrumentation, methods, and techniques 1 INTRODUCTION lation was not observed (.e.g. -
Arxiv:1607.06007V1
Accepted in ApJ A Preprint typeset using L TEX style emulateapj v. 11/12/01 THERMAL INFRARED IMAGING AND ATMOSPHERIC MODELING OF VHS J125601.92-125723.9 b: EVIDENCE FOR MODERATELY THICK CLOUDS AND EQUILIBRIUM CARBON CHEMISTRY IN A HIERARCHICAL TRIPLE SYSTEM Evan A. Rich1, Thayne Currie2, John P. Wisniewski1, Jun Hashimoto3, Timothy D. Brandt4,5, Joseph C. Carson6, Masayuki Kuzuhara7, Taichi Uyama8 Accepted in ApJ ABSTRACT We present and analyze Subaru/IRCS L′and M ′ images of the nearby M dwarf VHS J125601.92- 125723.9 (VHS 1256), which was recently claimed to have a ∼11 MJ companion (VHS 1256 b) at ∼102 au separation. Our adaptive optics images partially resolve the central star into a binary, whose components are nearly equal in brightness and separated by 0′′. 106 ± 0′′. 001. VHS 1256 b occupies nearly the same near-infrared color-magnitude diagram position as HR 8799 bcde and has a comparable L′ brightness. However, it has a substantially redder H - M ′ color, implying a relatively brighter M ′ flux density than for the HR 8799 planets and suggesting that non-equilibrium carbon chemistry may be less significant in VHS 1256 b. We successfully match the entire SED (optical through thermal infrared) for VHS 1256 b to atmospheric models assuming chemical equilibrium, models which failed to reproduce HR 8799 b at 5 µm. Our modeling favors slightly thick clouds in the companion’s atmosphere, although perhaps not quite as thick as those favored recently for HR 8799 bcde. Combined with the non-detection of lithium in the primary, we estimate that the system is at least older than 200 Myr and the masses of the stars comprising the central binary are at least 58 MJ each. -
Constraints on the Spin Evolution of Young Planetary-Mass Companions Marta L
Constraints on the Spin Evolution of Young Planetary-Mass Companions Marta L. Bryan1, Björn Benneke2, Heather A. Knutson2, Konstantin Batygin2, Brendan P. Bowler3 1Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA. 2Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. 3McDonald Observatory and Department of Astronomy, University of Texas at Austin, Austin, TX 78712, USA. Surveys of young star-forming regions have discovered a growing population of planetary- 1 mass (<13 MJup) companions around young stars . There is an ongoing debate as to whether these companions formed like planets (that is, from the circumstellar disk)2, or if they represent the low-mass tail of the star formation process3. In this study we utilize high-resolution spectroscopy to measure rotation rates of three young (2-300 Myr) planetary-mass companions and combine these measurements with published rotation rates for two additional companions4,5 to provide a look at the spin distribution of these objects. We compare this distribution to complementary rotation rate measurements for six brown dwarfs with masses <20 MJup, and show that these distributions are indistinguishable. This suggests that either that these two populations formed via the same mechanism, or that processes regulating rotation rates are independent of formation mechanism. We find that rotation rates for both populations are well below their break-up velocities and do not evolve significantly during the first few hundred million years after the end of accretion. This suggests that rotation rates are set during late stages of accretion, possibly by interactions with a circumplanetary disk. -
Direct Imaging and Spectroscopy of a Candidate Companion Below/Near
Draft version June 13, 2018 Preprint typeset using LATEX style emulateapj v. 5/2/11 DIRECT IMAGING AND SPECTROSCOPY OF A CANDIDATE COMPANION BELOW/NEAR THE DEUTERIUM-BURNING LIMIT IN THE YOUNG BINARY STAR SYSTEM, ROXS 42B Thayne Currie1, Sebastian Daemgen1, John Debes2, David Lafreniere3, Yoichi Itoh4, Ray Jayawardhana1, Thorsten Ratzka5, Serge Correia6 Draft version June 13, 2018 ABSTRACT We present near-infrared high-contrast imaging photometry and integral field spectroscopy of ROXs 42B, a binary M0 member of the 1–3 Myr-old ρ Ophiuchus star-forming region, from data collected ′′ over 7 years. Each data set reveals a faint companion – ROXs 42Bb – located ∼ 1.16 (rproj ≈ 150 AU) from the primaries at a position angle consistent with a point source identified earlier by Ratzka et al. (2005). ROXs 42Bb’s astrometry is inconsistent with a background star but consistent with a bound companion, possibly one with detected orbital motion. The most recent data set reveals a second candidate companion at ∼ 0′′. 5 of roughly equal brightness, though preliminary analysis indicates it is a background object. ROXs 42Bb’s H and Ks band photometry is similar to dusty/cloudy young, low-mass late M/early L dwarfs. K-band VLT/SINFONI spectroscopy shows ROXs 42Bb to be a cool substellar object (M8–L0; Teff ≈ 1800–2600 K), not a background dwarf star, with a spectral shape indicative of young, low surface gravity planet-mass companions. We estimate ROXs 42Bb’s mass to be 6–15 MJ , either below the deuterium burning limit and thus planet mass or straddling the deuterium-burning limit nominally separating planet-mass companions from other substellar objects. -
The State of Anthro–Earth
The Rosette Gazette Volume 22,, IssueIssue 7 Newsletter of the Rose City Astronomers July, 2010 RCA JULY 19 GENERAL MEETING The State Of Anthro–Earth THE STATE OF ANTHRO-EARTH: A Visitor From Far, Far Away Reviews the Status of Our Planet In This Issue: A Talk (in Earth-English) By Richard Brenne 1….General Meeting Enrico Fermi famously wondered why we hadn't heard from any other planetary 2….Club Officers civilizations, and Richard Brenne, who we'd always suspected was probably from another planet, thinks he might know the answer. Carl Sagan thought it was likely …...Magazines because those on other planets blew themselves up with nuclear weapons, but Richard …...RCA Library thinks its more likely that burning fossil fuels changed the climates and collapsed the 3….Local Happenings civilizations of those we might otherwise have heard from. Only someone from another planet could discuss this most serious topic with Richard's trademark humor 4…. Telescope (in a previous life he was an award-winning screenwriter - on which planet we're not Transformation sure) and bemused detachment. 5….Special Interest Groups Richard Brenne teaches a NASA-sponsored Global Climate Change class, serves on 6….Star Party Scene the American Meteorological Society's Committee to Communicate Climate Change, has written and produced documentaries about climate change since 1992, and has 7.…Observers Corner produced and moderated 50 hours of panel discussions about climate change with 18...RCA Board Minutes many of the world's top climate change scientists. Richard writes for the blog "Climate Progress" and his forthcoming book is titled "Anthro-Earth", his new name 20...Calendars for his adopted planet. -
Arxiv:2105.11583V2 [Astro-Ph.EP] 2 Jul 2021 Keck-HIRES, APF-Levy, and Lick-Hamilton Spectrographs
Draft version July 6, 2021 Typeset using LATEX twocolumn style in AASTeX63 The California Legacy Survey I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades Lee J. Rosenthal,1 Benjamin J. Fulton,1, 2 Lea A. Hirsch,3 Howard T. Isaacson,4 Andrew W. Howard,1 Cayla M. Dedrick,5, 6 Ilya A. Sherstyuk,1 Sarah C. Blunt,1, 7 Erik A. Petigura,8 Heather A. Knutson,9 Aida Behmard,9, 7 Ashley Chontos,10, 7 Justin R. Crepp,11 Ian J. M. Crossfield,12 Paul A. Dalba,13, 14 Debra A. Fischer,15 Gregory W. Henry,16 Stephen R. Kane,13 Molly Kosiarek,17, 7 Geoffrey W. Marcy,1, 7 Ryan A. Rubenzahl,1, 7 Lauren M. Weiss,10 and Jason T. Wright18, 19, 20 1Cahill Center for Astronomy & Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA 2IPAC-NASA Exoplanet Science Institute, Pasadena, CA 91125, USA 3Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA 4Department of Astronomy, University of California Berkeley, Berkeley, CA 94720, USA 5Cahill Center for Astronomy & Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA 6Department of Astronomy & Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA 7NSF Graduate Research Fellow 8Department of Physics & Astronomy, University of California Los Angeles, Los Angeles, CA 90095, USA 9Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA 10Institute for Astronomy, University of Hawai`i, -
Arxiv:0808.3207V1 [Astro-Ph] 23 Aug 2008 Nfgr .Nwonsaswr Rtdrcl Icvrdi C in Discovered Directly H first Were and Surroun Stars Variability Area Newborn the of 4
Handbook of Star Forming Regions Vol. II Astronomical Society of the Pacific, 2008 Bo Reipurth, ed. Chamaeleon Kevin L. Luhman Department of Astronomy and Astrophysics The Pennsylvania State University University Park, PA 16802, USA Abstract. The dark clouds in the constellation of Chamaeleon have distances of 160-180pc from the Sun and a total mass of ∼5000 M⊙. The three main clouds, Cha I, II, and III, have angular sizes of a few square degrees and maximum extinctions of AV ∼ 5-10. Most of the star formation in these clouds is occurring in Cha I, with the remainder in Cha II. The current census of Cha I contains 237 known members, 33 of which have spectral types indicative of brown dwarfs (>M6). Approximately 50 members of Cha II have been identified, including a few brown dwarfs. When interpreted with the evolutionary models of Chabrier and Baraffe, the H-R diagram for Cha I exhibits a median age of ∼2 Myr, making it coeval with IC 348 and slightly older than Taurus (∼1 Myr). TheIMF ofChaI reachesa maximumat a massof0.1-0.15 M⊙, and thus closely resembles the IMFs in IC 348 and the Orion Nebula Cluster. The disk fraction in Cha I is roughly constant at ∼ 50% from 0.01 to 0.3 M⊙ and increases to ∼ 65% at higher masses. In comparison, IC 348 has a similar disk fraction at low masses but a much lower disk fraction at M ∼> 1 M⊙, indicating that solar-type stars have longer disk lifetimes in Cha I. 1. Introduction The southern constellation of Chamaeleon contains one of the nearest groups of dark clouds to the Sun (d ∼ 160-180 pc). -
Correlations Between the Stellar, Planetary, and Debris Components of Exoplanet Systems Observed by Herschel⋆
A&A 565, A15 (2014) Astronomy DOI: 10.1051/0004-6361/201323058 & c ESO 2014 Astrophysics Correlations between the stellar, planetary, and debris components of exoplanet systems observed by Herschel J. P. Marshall1,2, A. Moro-Martín3,4, C. Eiroa1, G. Kennedy5,A.Mora6, B. Sibthorpe7, J.-F. Lestrade8, J. Maldonado1,9, J. Sanz-Forcada10,M.C.Wyatt5,B.Matthews11,12,J.Horner2,13,14, B. Montesinos10,G.Bryden15, C. del Burgo16,J.S.Greaves17,R.J.Ivison18,19, G. Meeus1, G. Olofsson20, G. L. Pilbratt21, and G. J. White22,23 (Affiliations can be found after the references) Received 15 November 2013 / Accepted 6 March 2014 ABSTRACT Context. Stars form surrounded by gas- and dust-rich protoplanetary discs. Generally, these discs dissipate over a few (3–10) Myr, leaving a faint tenuous debris disc composed of second-generation dust produced by the attrition of larger bodies formed in the protoplanetary disc. Giant planets detected in radial velocity and transit surveys of main-sequence stars also form within the protoplanetary disc, whilst super-Earths now detectable may form once the gas has dissipated. Our own solar system, with its eight planets and two debris belts, is a prime example of an end state of this process. Aims. The Herschel DEBRIS, DUNES, and GT programmes observed 37 exoplanet host stars within 25 pc at 70, 100, and 160 μm with the sensitiv- ity to detect far-infrared excess emission at flux density levels only an order of magnitude greater than that of the solar system’s Edgeworth-Kuiper belt. Here we present an analysis of that sample, using it to more accurately determine the (possible) level of dust emission from these exoplanet host stars and thereafter determine the links between the various components of these exoplanetary systems through statistical analysis. -