Detecting and Characterizing Stellar Companions To
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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. -
Herschel Observations of Debris Discs Orbiting Planet-Hosting Subgiants
Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 14 November 2013 (MN LATEX style file v2.2) Herschel Observations of Debris Discs Orbiting Planet-hosting Subgiants Amy Bonsor1,2⋆, Grant M. Kennedy3, Mark C. Wyatt3, John A. Johnson4 and Bruce Sibthorpe5 1UJF-Grenoble 1 / CNRS-INSU, Institut de Plantologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041, France 2School of Physics, H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK 3Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 OHA, UK 4Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 5SRON Netherlands Institute for Space Research, Zernike Building, P.O. Box 800, 9700 AV Groningen, The Netherlands 14 November 2013 ABSTRACT Debris discs are commonly detected orbiting main-sequence stars, yet little is known regarding their fate as the star evolves to become a giant. Recent observations of radial velocity detected planets orbiting giant stars highlight this population and its im- portance for probing, for example, the population of planetary systems orbiting intermediate mass stars. Our Herschel ∗ survey observed a subset of the Johnson et al program subgiants, find- ing that 4/36 exhibit excess emission thought to indicate debris, of which 3/19 are planet-hosting stars and 1/17 are stars with no current planet detections. Given the small numbers involved, there is no evidence that the disc detection rate around stars with plan- ets is different to that around stars without planets. Our detections provide a clear indication that large quantities of dusty material can survive the stars’ main-sequence lifetime and be detected on the subgiant branch, with important implications for the evolution of planetary systems and observations of polluted or dusty white dwarfs. -
The Evening Sky Map a DECEMBER 2018 N
I N E D R I A C A S T N E O D I T A C L E O R N I G D S T S H A E P H M O O R C I . Z N O n i f d o P t o ) l a h O N r g i u s , o Z l t P h I C e r o N R ( I o r R r O e t p h C H p i L S t D E E a g r i . H ( B T F e O h T NORTH D R t h N e M e E s A G X O U e A H m M C T i . I n P i N d S L E E m P Z “ e E A N Dipper t e H O NORTHERN HEMISPHERE o M T R r T The Big The N Y s H h . E r o ” E K Alcor & e w ) t W S . s e . T u r T Mizar l E U p W C B e R e a N l W D k b E s T u T MAJOR W H o o The Evening Sky Map A DECEMBER 2018 n E C D O t FREE* EACH MONTH FOR YOU TO EXPLORE, LEARN & ENJOY THE NIGHT SKY URSA S e L h K h e t Y E m R d M A n o A a r Thuban S SKY MAP SHOWS HOW P Get Sky Calendar on Twitter n T 1 i n C A 3 E g R M J http://twitter.com/skymaps O Sky Calendar – December 2018 o d B THE NIGHT SKY LOOKS U M13 f n O N i D “ f L D e T DRACO A o c NE O I t I e T EARLY DEC PM T 8 m P t S i 3 Moon near Spica (morning sky) at 9h UT. -
Explore the Universe Observing Certificate Second Edition
RASC Observing Committee Explore the Universe Observing Certificate Second Edition Explore the Universe Observing Certificate Welcome to the Explore the Universe Observing Certificate Program. This program is designed to provide the observer with a well-rounded introduction to the night sky visible from North America. Using this observing program is an excellent way to gain knowledge and experience in astronomy. Experienced observers find that a planned observing session results in a more satisfying and interesting experience. This program will help introduce you to amateur astronomy and prepare you for other more challenging certificate programs such as the Messier and Finest NGC. The program covers the full range of astronomical objects. Here is a summary: Observing Objective Requirement Available Constellations and Bright Stars 12 24 The Moon 16 32 Solar System 5 10 Deep Sky Objects 12 24 Double Stars 10 20 Total 55 110 In each category a choice of objects is provided so that you can begin the certificate at any time of the year. In order to receive your certificate you need to observe a total of 55 of the 110 objects available. Here is a summary of some of the abbreviations used in this program Instrument V – Visual (unaided eye) B – Binocular T – Telescope V/B - Visual/Binocular B/T - Binocular/Telescope Season Season when the object can be best seen in the evening sky between dusk. and midnight. Objects may also be seen in other seasons. Description Brief description of the target object, its common name and other details. Cons Constellation where object can be found (if applicable) BOG Ref Refers to corresponding references in the RASC’s The Beginner’s Observing Guide highlighting this object. -
Homogeneous Spectroscopic Parameters for Bright Planet Host Stars from the Northern Hemisphere the Impact on Stellar and Planetary Mass (Research Note)
A&A 576, A94 (2015) Astronomy DOI: 10.1051/0004-6361/201425227 & c ESO 2015 Astrophysics Homogeneous spectroscopic parameters for bright planet host stars from the northern hemisphere The impact on stellar and planetary mass (Research Note) S. G. Sousa1,2,N.C.Santos1,2, A. Mortier1,3,M.Tsantaki1,2, V. Adibekyan1, E. Delgado Mena1,G.Israelian4,5, B. Rojas-Ayala1,andV.Neves6 1 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal 3 SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK 4 Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain 5 Departamento de Astrofísica, Universidade de La Laguna, 38205 La Laguna, Tenerife, Spain 6 Departamento de Física, Universidade Federal do Rio Grande do Norte, Brazil Received 27 October 2014 / Accepted 19 February 2015 ABSTRACT Aims. In this work we derive new precise and homogeneous parameters for 37 stars with planets. For this purpose, we analyze high resolution spectra obtained by the NARVAL spectrograph for a sample composed of bright planet host stars in the northern hemisphere. The new parameters are included in the SWEET-Cat online catalogue. Methods. To ensure that the catalogue is homogeneous, we use our standard spectroscopic analysis procedure, ARES+MOOG, to derive effective temperatures, surface gravities, and metallicities. These spectroscopic stellar parameters are then used as input to compute the stellar mass and radius, which are fundamental for the derivation of the planetary mass and radius. -