The Ca Ii Infrared Triplet's Performance As an Activity Indicator Compared To
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Université De Montréal Relevé Polarimétrique D'étoiles Candidates
Université de Montréal Relevé polarimétrique d’étoiles candidates pour des disques de débris par Amélie Simon Département de physique Faculté des arts et des sciences Mémoire présenté à la Faculté des études supérieures en vue de l’obtention du grade de Maître ès sciences (M.Sc.) en physique Août, 2010 c Amélie Simon, 2010 Université de Montréal Faculté des études supérieures Ce mémoire intitulé: Relevé polarimétrique d’étoiles candidates pour des disques de débris présenté par: Amélie Simon a été évalué par un jury composé des personnes suivantes: Serge Demers, président-rapporteur Pierre Bastien, directeur de recherche Gilles Fontaine, membre du jury Mémoire accepté le: Sommaire Le relevé DEBRIS est effectué par le télescope spatial Herschel. Il permet d’échantillonner les disques de débris autour d’étoiles de l’environnement solaire. Dans la première partie de ce mémoire, un relevé polarimétrique de 108 étoiles des candidates de DEBRIS est présenté. Utilisant le polarimètre de l’Observatoire du Mont-Mégantic, des observations ont été effec- tuées afin de détecter la polarisation due à la présence de disques de débris. En raison d’un faible taux de détection d’étoiles polarisées, une analyse statistique a été réalisée dans le but de comparer la polarisation d’étoiles possédant un excès dans l’infrarouge et la polarisation de celles n’en possédant pas. Utilisant la théorie de diffusion de Mie, un modèle a été construit afin de prédire la polarisation due à un disque de débris. Les résultats du modèle sont cohérents avec les observations. La deuxième partie de ce mémoire présente des tests optiques du polarimètre POL-2, construit à l’Université de Montréal. -
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. -
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:0705.4290V2 [Astro-Ph] 23 Aug 2007
DRAFT VERSION NOVEMBER 11, 2018 Preprint typeset using LATEX style emulateapj v. 08/13/06 THE GEMINI DEEP PLANET SURVEY – GDPS∗ DAVID LAFRENIÈREA,RENÉ DOYONA , CHRISTIAN MAROISB ,DANIEL NADEAUA, BEN R. OPPENHEIMERC,PATRICK F. ROCHED , FRANÇOIS RIGAUTE, JAMES R. GRAHAMF ,RAY JAYAWARDHANAG,DOUG JOHNSTONEH,PAUL G. KALASF ,BRUCE MACINTOSHB, RENÉ RACINEA Draft version November 11, 2018 ABSTRACT We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope and angular differential imaging was used to suppress the speckle noise of the central star. Detection limits for the 85 stars observed are presented, along with a list of all faint point sources detected around them. Typically, the observations are sensitive to angular separations beyond 0.5′′ with 5σ contrast sensitivities in magnitude difference at 1.6 µm of 9.5 at 0.5′′, 12.9 at 1′′, 15.0 at 2′′, and 16.5 at 5′′. For the typical target of the survey, a 100 Myr old K0 star located 22 pc from the Sun, the observations are sensitive enough to detect planets more massive than 2 MJup with a projected separation in the range 40–200 AU. Depending on the age, spectral type, and distance of the target stars, the detection limit can be as low as 1 MJup. Second epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are∼ unrelated background stars. A detailed statistical analysis of the survey results, yielding upper limits on the fractions of stars with giant planet or low mass brown dwarf companions, is presented. -
Frequency of Debris Disks Around Solar-Type Stars: First Results from a Spitzer Mips Survey G
The Astrophysical Journal, 636:1098–1113, 2006 January 10 A # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. FREQUENCY OF DEBRIS DISKS AROUND SOLAR-TYPE STARS: FIRST RESULTS FROM A SPITZER MIPS SURVEY G. Bryden,1 C. A. Beichman,2 D. E. Trilling,3 G. H. Rieke,3 E. K. Holmes,1,4 S. M. Lawler,1 K. R. Stapelfeldt,1 M. W. Werner,1 T. N. Gautier,1 M. Blaylock,3 K. D. Gordon,3 J. A. Stansberry,3 and K. Y. L. Su3 Received 2005 August 1; accepted 2005 September 12 ABSTRACT We have searched for infrared excesses around a well-defined sample of 69 FGK main-sequence field stars. These stars were selected without regard to their age, metallicity, or any previous detection of IR excess; they have a median age of 4 Gyr. We have detected 70 m excesses around seven stars at the 3 confidence level. This extra emission is produced by cool material (<100 K) located beyond 10 AU, well outside the ‘‘habitable zones’’ of these systems and consistent with the presence of Kuiper Belt analogs with 100 times more emitting surface area than in our own planetary system. Only one star, HD 69830, shows excess emission at 24 m, corresponding to dust with temper- À3 atures k300 K located inside of 1 AU. While debris disks with Ldust /L? 10 are rare around old FGK stars, we find À4 À5 that the disk frequency increases from 2% Æ 2% for Ldust /L? 10 to 12% Æ 5% for Ldust /L? 10 . -
Asymptotic and Measured Large Frequency Separations
Astronomy & Astrophysics manuscript no. mesure11 c ESO 2018 September 11, 2018 Asymptotic and measured large frequency separations B. Mosser1, E. Michel1, K. Belkacem1, M.J. Goupil1, A. Baglin1, C. Barban1, J. Provost2, R. Samadi1, M. Auvergne1, and C. Catala1 1 LESIA, CNRS, Universit´ePierre et Marie Curie, Universit´e Denis Diderot, Observatoire de Paris, 92195 Meudon cedex, France; e-mail: [email protected] 2 Universit´ede Nice-Sophia Antipolis, CNRS UMR 7293, Observatoire de la Cˆote d’Azur, Laboratoire J.L. Lagrange, BP 4229, 06304 Nice Cedex 04, France Preprint online version: September 11, 2018 ABSTRACT Context. With the space-borne missions CoRoT and Kepler, a large amount of asteroseismic data is now available and has led to a variety of work. So-called global oscillation parameters are inferred to characterize the large sets of stars, perform ensemble asteroseismology, and derive scaling relations. The mean large separation is such a key parameter, easily deduced from the radial-frequency differences in the observed oscillation spectrum and closely related to the mean stellar density. It is therefore crucial to measure it with the highest accuracy in order to obtain the most precise asteroseismic indices. Aims. As the conditions of measurement of the large separation do not coincide with its theoretical definition, we revisit the asymptotic expressions used for analyzing the observed oscillation spectra. Then, we examine the consequence of the difference between the observed and asymptotic values of the mean large separation. Methods. The analysis is focused on radial modes. We use series of radial-mode frequencies in published analyses of stars with solar-like oscillations to compare the asymptotic and observational values of the large separation. -
K2-295 B and K2-237 B: Two Transiting Hot Jupiters A.M.S
doi: 10.32023/0001-5237/69.2.3 ACTA ASTRONOMICA Vol. 69 (2019) pp. 135–158 K2-295 b and K2-237 b: Two Transiting Hot Jupiters A.M.S. Smith1 , Sz.Csizmadia1 ,D. Gandolfi2 , S.Albrecht3 , R.Alonso4,5 , O.Barragán2 , J.Cabrera1 , W.D.Cochran6 , F. Dai7 , H. Deeg4,5 , Ph.Eigmüller1,8 , M.Endl6 , A.Erikson1 , M. Fridlund9,10,4 , A.Fukui11,4 , S.Grziwa12 , E.W. Guenther13 , A.P. Hatzes13 , D.Hidalgo4,5 , T.Hirano14 , J.Korth12 , M.Kuzuhara15,16 , J.Livingston17 , N.Narita17,15,16,4 , D.Nespral4,5 , P. Niraula18 , G.Nowak4,5 , E.Palle4,5 , M.Pätzold12 , C.M. Persson10 , J.Prieto-Arranz4,5 , H.Rauer1,8,19 , S. Redfield18 , I.Ribas20,21 and V. Van Eylen9 1 Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489 Berlin, Germany e-mail:[email protected] 2 Dipartimento di Fisica, Universitá di Torino, Via P. Giuria 1, I-10125, Torino, Italy 3 Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark 4 Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Tenerife, Spain 5 Departamento de Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain 6 Department of Astronomy and McDonald Observatory, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712, USA 7 Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139,USA 8 Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany 9 Leiden Observatory, -
The Top Ten Solar Analogs in the ELODIE Library
A&A 418, 1089–1100 (2004) Astronomy DOI: 10.1051/0004-6361:20035708 & c ESO 2004 Astrophysics The Top Ten solar analogs in the ELODIE library C. Soubiran1 and A. Triaud1,2 1 Observatoire Aquitain des Sciences de l’Univers, UMR 5804, 2 rue de l’Observatoire, 33270 Floirac, France 2 University of St-Andrews, School of Physics and Astronomy, North Haugh, St Andrews, Fife KY16 9SS, Scotland Received 18 November 2003 / Accepted 22 January 2004 Abstract. Several solar analogs have been identified in the library of high resolution stellar spectra taken with the echelle spec- trograph ELODIE. A purely differential method has been used, based on the χ2 comparison of a large number of G dwarf spectra to 8 spectra of the Sun, taken on the Moon and Ceres. HD 146233 keeps its status of closest ever solar twin (Porto de Mello & da Silva 1997). Some other spectroscopic analogs have never been studied before, while the two planet-host stars HD 095128 and HD 186427 are also part of the selection. The fundamental parameters found in the literature for these stars show a surpris- ing dispersion, partly due to the uncertainties which affect them. We discuss the advantages and drawbacks of photometric and spectroscopic methods to search for solar analogs and conclude that they have to be used jointly to find real solar twins. Key words. stars: fundamental parameters – Sun: fundamental parameters 1. Introduction Sun. With the advance of techniques in high resolution spec- troscopy and solid state detectors, and with the progress in The Sun is the best-known star: its fundamental parameters modelling stellar atmospheres, measurements of (T ff,logg, ff e (radius, mass, age, luminosity, e ective temperature, chemi- [Fe/H]) became of higher precision allowing the search for so- cal composition) are known with a good accuracy, as well as lar analogs by comparing their atmospheric parameters to those its internal structure, activity, velocity field and magnetic field. -
The Effects of Stellar Winds on the Magnetospheres and Potential Habitability of Exoplanets
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by St Andrews Research Repository A&A 570, A99 (2014) Astronomy DOI: 10.1051/0004-6361/201424323 & c ESO 2014 Astrophysics The effects of stellar winds on the magnetospheres and potential habitability of exoplanets V. S ee 1, M. Jardine1,A.A.Vidotto1,2,P.Petit3,4, S. C. Marsden5,S.V.Jeffers6, and J. D. do Nascimento Jr.7,8 1 SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, KY16 9SS, St Andrews, UK e-mail: [email protected] 2 Observatoire de Genève, Université de Genève, Chemin des Maillettes 51, 1290 Sauverny, Switzerland 3 Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysique et Planétologie, 31400 Toulouse, France 4 CNRS, Institut de Recherche en Astrophysique et Planétologie, 14 Avenue Édouard Belin, 31400 Toulouse, France 5 Computational Engineering and Science Research Centre, University of Southern Queensland, 4350 Toowoomba, Australia 6 Universität Göttingen, Institut für Astrophysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany 7 Departmento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, CEP:59072-970 Natal, RN, Brazil 8 Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA Received 2 June 2014 / Accepted 6 August 2014 ABSTRACT Context. The principle definition of habitability for exoplanets is whether they can sustain liquid water on their surfaces, i.e. that they orbit within the habitable zone. However, the planet’s magnetosphere should also be considered, since without it, an exoplanet’s atmosphere may be eroded away by stellar winds. -
Université De Montréal Relevé De Planètes Géantes Autour D'étoiles
Université de Montréal Relevé de planètes géantes autour d’étoiles proches par imagerie directe et optimisation d’une technique d’imagerie multibande par David Lafrenière Département de physique Faculté des arts et des sciences Thèse présentée à la Faculté des études supérieures en vue de l’obtention du grade de Philosophiœ Doctor (Ph.D.) en physique Avril, 2007 © David Lafrenière, 2007. o o Université (III de Montréal Direction des bib1othèques AVIS L’auteur a autorisé l’Université de Montréal à reproduire et diffuser, en totalité ou en partie, par quelque moyen que ce soit et sur quelque support que ce soit, et exclusivement à des fins non lucratives d’enseignement et de recherche, des copies de ce mémoire ou de cette thèse. L’auteur et les coauteurs le cas échéant conservent la propriété du droit d’auteur et des droits moraux qui protègent ce document. Ni la thèse ou le mémoire, ni des extraits substantiels de ce document, ne doivent être imprimés ou autrement reproduits sans l’autorisation de l’auteur. Afin de se conformer à la Loi canadienne sur la protection des renseignements personnels, quelques formulaires secondaires, coordonnées ou signatures intégrées au texte ont pu être enlevés de ce document. Bien que cela ait pu affecter la pagination, il n’y a aucun contenu manquant. NOTICE The author of this thesis or dissertation has granted a nonexciusive license allowing Université de Montréal to reproduce and publish the document, in part or in whole, and in any format, solely for noncommercial educationaT and research purposes. The author and co-authors if applicable retain copyright ownership and morel rights in this document. -
The Effects of Stellar Winds on the Magnetospheres and Potential Habitability of Exoplanets
A&A 570, A99 (2014) Astronomy DOI: 10.1051/0004-6361/201424323 & c ESO 2014 Astrophysics The effects of stellar winds on the magnetospheres and potential habitability of exoplanets V. S ee 1, M. Jardine1,A.A.Vidotto1,2,P.Petit3,4, S. C. Marsden5,S.V.Jeffers6, and J. D. do Nascimento Jr.7,8 1 SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, KY16 9SS, St Andrews, UK e-mail: [email protected] 2 Observatoire de Genève, Université de Genève, Chemin des Maillettes 51, 1290 Sauverny, Switzerland 3 Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysique et Planétologie, 31400 Toulouse, France 4 CNRS, Institut de Recherche en Astrophysique et Planétologie, 14 Avenue Édouard Belin, 31400 Toulouse, France 5 Computational Engineering and Science Research Centre, University of Southern Queensland, 4350 Toowoomba, Australia 6 Universität Göttingen, Institut für Astrophysik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany 7 Departmento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, CEP:59072-970 Natal, RN, Brazil 8 Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA Received 2 June 2014 / Accepted 6 August 2014 ABSTRACT Context. The principle definition of habitability for exoplanets is whether they can sustain liquid water on their surfaces, i.e. that they orbit within the habitable zone. However, the planet’s magnetosphere should also be considered, since without it, an exoplanet’s atmosphere may be eroded away by stellar winds. Aims. The aim of this paper is to investigate magnetospheric protection of a planet from the effects of stellar winds from solar-mass stars. -
Arxiv:1207.6212V2 [Astro-Ph.GA] 1 Aug 2012
Draft: Submitted to ApJ Supp. A Preprint typeset using LTEX style emulateapj v. 5/2/11 PRECISE RADIAL VELOCITIES OF 2046 NEARBY FGKM STARS AND 131 STANDARDS1 Carly Chubak2, Geoffrey W. Marcy2, Debra A. Fischer5, Andrew W. Howard2,3, Howard Isaacson2, John Asher Johnson4, Jason T. Wright6,7 (Received; Accepted) Draft: Submitted to ApJ Supp. ABSTRACT We present radial velocities with an accuracy of 0.1 km s−1 for 2046 stars of spectral type F,G,K, and M, based on ∼29000 spectra taken with the Keck I telescope. We also present 131 FGKM standard stars, all of which exhibit constant radial velocity for at least 10 years, with an RMS less than 0.03 km s−1. All velocities are measured relative to the solar system barycenter. Spectra of the Sun and of asteroids pin the zero-point of our velocities, yielding a velocity accuracy of 0.01 km s−1for G2V stars. This velocity zero-point agrees within 0.01 km s−1 with the zero-points carefully determined by Nidever et al. (2002) and Latham et al. (2002). For reference we compute the differences in velocity zero-points between our velocities and standard stars of the IAU, the Harvard-Smithsonian Center for Astrophysics, and l’Observatoire de Geneve, finding agreement with all of them at the level of 0.1 km s−1. But our radial velocities (and those of all other groups) contain no corrections for convective blueshift or gravitational redshifts (except for G2V stars), leaving them vulnerable to systematic errors of ∼0.2 km s−1 for K dwarfs and ∼0.3 km s−1 for M dwarfs due to subphotospheric convection, for which we offer velocity corrections.