Connecting Substellar and Stellar Formation. the Role of the Host Star's
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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. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
Stars IV Stellar Evolution Attendance Quiz
Stars IV Stellar Evolution Attendance Quiz Are you here today? Here! (a) yes (b) no (c) my views are evolving on the subject Today’s Topics Stellar Evolution • An alien visits Earth for a day • A star’s mass controls its fate • Low-mass stellar evolution (M < 2 M) • Intermediate and high-mass stellar evolution (2 M < M < 8 M; M > 8 M) • Novae, Type I Supernovae, Type II Supernovae An Alien Visits for a Day • Suppose an alien visited the Earth for a day • What would it make of humans? • It might think that there were 4 separate species • A small creature that makes a lot of noise and leaks liquids • A somewhat larger, very energetic creature • A large, slow-witted creature • A smaller, wrinkled creature • Or, it might decide that there is one species and that these different creatures form an evolutionary sequence (baby, child, adult, old person) Stellar Evolution • Astronomers study stars in much the same way • Stars come in many varieties, and change over times much longer than a human lifetime (with some spectacular exceptions!) • How do we know they evolve? • We study stellar properties, and use our knowledge of physics to construct models and draw conclusions about stars that lead to an evolutionary sequence • As with stellar structure, the mass of a star determines its evolution and eventual fate A Star’s Mass Determines its Fate • How does mass control a star’s evolution and fate? • A main sequence star with higher mass has • Higher central pressure • Higher fusion rate • Higher luminosity • Shorter main sequence lifetime • Larger -
Leilão 28 Julho 16
LEILÃO DE PRODUTOS DA GERAÇÃO 2014 & ANIMAIS EM TREINAMENTO PRODUTOS DA GERAÇÃO 2014 STUD TNT HARAS CAMPESTRE HARAS CENTRO SERRA HARAS LOUVEIRA HARAS OLD FRIENDS HARAS SAN FRANCESCO HARAS SANTA CAMILA STUD ETERNAMENTE RIO STUD V DE VILLELA T R E I N A M E N T O HARAS ANDERSON HARAS CAMPESTRE HARAS CLARK LEITE STUD BLUE MOUNTAIN STUD ETERNAMENTE RIO HARAS FIGUEIRA DO LAGO COUDELARIA JESSICA FAZENDA MONDESIR STUD PERFORMANCE HARAS REGINA 28 JULHO 2016 - 5ª FEIRA - 20:00 HS. TATTERSALL DO JOCKEY CLUB BRSILEIRO TRANSMISSÃO AO VIVO PELA INTERNET www.appsvirtual.com.br LEILÃO DE PRODUTOS DA GERAÇÃO 2014 E ANIMAIS EM TREINAMENTO COMPRE POR TELEFONE: (21) 2274-5252 (21) 3534-9282 (21) 3534-9283 (21) 2511-6324 RAMAL LEILÃO (11) 98918.1477 (11) 99352.1144 (11) 99461.6829 ATRAVÉS DESTES NÚMEROS VOCÊ PODERÁ CONTACTAR SEU AGENTE OU REPRESENTANTE TRANSMISSÃO AO VIVO PELA INTERNET INTERNET www.appsvirtual.com.br ALOJAMENTOS DOS PRODUTOS DA GERAÇÃO 2014 OS ANIMAIS FICARÃO ALOJADOS NO HIPÓDROMO DA GÁVEA STUD TNT Vila Hipíca - Grupo 2 STUD ETERNAMENTE RIO Vila Hípica - Grupo 36 STUD V DE VILLELA Vila Hípica - Grupo 2 HARAS CAMPESTRE Vila Tattersall - Grupo 9-A HARAS CENTRO SERRA Vila Hípica - Grupo 2 HARAS LOUVEIRA Vila Hípica - Grupo 2 HARAS OLD FRIENDS Vila Hípica - Grupo 2 HARAS NIJÚ Vila Hípica - Grupo 4 HARAS SAN FRANCESCO Vila Hípica - Grupo 2 HARAS SANTA CAMILA Vila - Hípica - Grupo 2 COPA LEILÕES JCB Produtos da Geração 2014 A ARRECADAÇÃO SERÁ DISTRIBUIDA COPATRAVÉSA LEILÕES DE 4 PROVAS JCB Potros de 2 anos 1.400m ABRIL 2017 Potrancas de 2 anos 1.400m Potros de 3 anos 1.600m SETEMBRO 2017 Potrancas de 3 anos 1.600m CONSULTE O REGULAMENTO DA COPA LEILÕES JCB NORMAS ESPECÍFICAS I - CONDIÇÕES GERAIS ART. -
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A&A 562, A92 (2014) Astronomy DOI: 10.1051/0004-6361/201321493 & c ESO 2014 Astrophysics Li depletion in solar analogues with exoplanets Extending the sample, E. Delgado Mena1,G.Israelian2,3, J. I. González Hernández2,3,S.G.Sousa1,2,4, A. Mortier1,4,N.C.Santos1,4, V. Zh. Adibekyan1, J. Fernandes5, R. Rebolo2,3,6,S.Udry7, and M. Mayor7 1 Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Instituto de Astrofísica de Canarias, C/ Via Lactea s/n, 38200 La Laguna, Tenerife, Spain 3 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain 4 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal 5 CGUC, Department of Mathematics and Astronomical Observatory, University of Coimbra, 3049 Coimbra, Portugal 6 Consejo Superior de Investigaciones Científicas, CSIC, Spain 7 Observatoire de Genève, Université de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland Received 18 March 2013 / Accepted 25 November 2013 ABSTRACT Aims. We want to study the effects of the formation of planets and planetary systems on the atmospheric Li abundance of planet host stars. Methods. In this work we present new determinations of lithium abundances for 326 main sequence stars with and without planets in the Teff range 5600–5900 K. The 277 stars come from the HARPS sample, the remaining targets were observed with a variety of high-resolution spectrographs. Results. We confirm significant differences in the Li distribution of solar twins (Teff = T ± 80 K, log g = log g ± 0.2and[Fe/H] = [Fe/H] ±0.2): the full sample of planet host stars (22) shows Li average values lower than “single” stars with no detected planets (60). -
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, -
Chapter 16 the Sun and Stars
Chapter 16 The Sun and Stars Stargazing is an awe-inspiring way to enjoy the night sky, but humans can learn only so much about stars from our position on Earth. The Hubble Space Telescope is a school-bus-size telescope that orbits Earth every 97 minutes at an altitude of 353 miles and a speed of about 17,500 miles per hour. The Hubble Space Telescope (HST) transmits images and data from space to computers on Earth. In fact, HST sends enough data back to Earth each week to fill 3,600 feet of books on a shelf. Scientists store the data on special disks. In January 2006, HST captured images of the Orion Nebula, a huge area where stars are being formed. HST’s detailed images revealed over 3,000 stars that were never seen before. Information from the Hubble will help scientists understand more about how stars form. In this chapter, you will learn all about the star of our solar system, the sun, and about the characteristics of other stars. 1. Why do stars shine? 2. What kinds of stars are there? 3. How are stars formed, and do any other stars have planets? 16.1 The Sun and the Stars What are stars? Where did they come from? How long do they last? During most of the star - an enormous hot ball of gas day, we see only one star, the sun, which is 150 million kilometers away. On a clear held together by gravity which night, about 6,000 stars can be seen without a telescope. -
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. -
Exoplanet.Eu Catalog Page 1 # Name Mass Star Name
exoplanet.eu_catalog # name mass star_name star_distance star_mass OGLE-2016-BLG-1469L b 13.6 OGLE-2016-BLG-1469L 4500.0 0.048 11 Com b 19.4 11 Com 110.6 2.7 11 Oph b 21 11 Oph 145.0 0.0162 11 UMi b 10.5 11 UMi 119.5 1.8 14 And b 5.33 14 And 76.4 2.2 14 Her b 4.64 14 Her 18.1 0.9 16 Cyg B b 1.68 16 Cyg B 21.4 1.01 18 Del b 10.3 18 Del 73.1 2.3 1RXS 1609 b 14 1RXS1609 145.0 0.73 1SWASP J1407 b 20 1SWASP J1407 133.0 0.9 24 Sex b 1.99 24 Sex 74.8 1.54 24 Sex c 0.86 24 Sex 74.8 1.54 2M 0103-55 (AB) b 13 2M 0103-55 (AB) 47.2 0.4 2M 0122-24 b 20 2M 0122-24 36.0 0.4 2M 0219-39 b 13.9 2M 0219-39 39.4 0.11 2M 0441+23 b 7.5 2M 0441+23 140.0 0.02 2M 0746+20 b 30 2M 0746+20 12.2 0.12 2M 1207-39 24 2M 1207-39 52.4 0.025 2M 1207-39 b 4 2M 1207-39 52.4 0.025 2M 1938+46 b 1.9 2M 1938+46 0.6 2M 2140+16 b 20 2M 2140+16 25.0 0.08 2M 2206-20 b 30 2M 2206-20 26.7 0.13 2M 2236+4751 b 12.5 2M 2236+4751 63.0 0.6 2M J2126-81 b 13.3 TYC 9486-927-1 24.8 0.4 2MASS J11193254 AB 3.7 2MASS J11193254 AB 2MASS J1450-7841 A 40 2MASS J1450-7841 A 75.0 0.04 2MASS J1450-7841 B 40 2MASS J1450-7841 B 75.0 0.04 2MASS J2250+2325 b 30 2MASS J2250+2325 41.5 30 Ari B b 9.88 30 Ari B 39.4 1.22 38 Vir b 4.51 38 Vir 1.18 4 Uma b 7.1 4 Uma 78.5 1.234 42 Dra b 3.88 42 Dra 97.3 0.98 47 Uma b 2.53 47 Uma 14.0 1.03 47 Uma c 0.54 47 Uma 14.0 1.03 47 Uma d 1.64 47 Uma 14.0 1.03 51 Eri b 9.1 51 Eri 29.4 1.75 51 Peg b 0.47 51 Peg 14.7 1.11 55 Cnc b 0.84 55 Cnc 12.3 0.905 55 Cnc c 0.1784 55 Cnc 12.3 0.905 55 Cnc d 3.86 55 Cnc 12.3 0.905 55 Cnc e 0.02547 55 Cnc 12.3 0.905 55 Cnc f 0.1479 55 -
HST/ACS Coronagraphic Images of a Debris Disk Around HD 92945
HST/ACS Coronagraphic Images of a Debris Disk around HD 92945 J. Krist (JPL), K. Stapelfeldt (JPL), D. Golimowski (Johns Hopkins), D. Ardila (Spitzer Science Center), M. Clampin (NASA/GSFC), C. Chen (NOAO), M. Werner (JPL), H. Ford (Johns Hopkins), G. Illingworth (U. California Santa Cruz), G. Schneider (Steward Obs.), M. Silverstone (Steward Obs.), D. Hines (Space Science Inst.), & the ACS Science Team Introduction Disk Characteristics HD 92945 is a nearby (22 pc) K1V star with an age of ~100 Myr (Song, Zuckerman, & The HD 92945 disk seen in the PSF-subtracted images appears inclined by about Bessell 2004). It was classified as a significant IR excess source by the Spitzer/MIPS 25° from edge-on with the projected major axis aligned along PA=100°. Within ~3” Science Team, confirming the Silverstone (2000) identification based on IRAS of the star the subtraction residuals caused by PSF mismatches prevent reliable measurements. As part of a collaborative effort between the MIPS and HST/ACS measurement of the disk, which is seen extending out to ~6.5” (146 AU). The disk Science Teams, the star was observed with the ACS coronagraph to search for the has a mean surface brightness of V=22.8 mag/arcsec2. Because the forward edge scattered light counterpart to the IR emission. We present preliminary results along the line of sight is hidden under the residuals, it is not possible to estimate here. the amount of foward scattering by the dust grains. The disk appears generally featureless. -6 The surface brightness profiles along the apparent major axis shows the “broken Figure 1. -
Transition from Spot to Faculae Domination--An Alternate
Astronomy & Astrophysics manuscript no. AC2_arxiv c ESO 2018 October 30, 2018 Transition from spot to faculae domination An alternate explanation for the dearth of intermediate Kepler rotation periods Timo Reinhold1; 2, Keaton J. Bell1; 2, James Kuszlewicz1; 2, Saskia Hekker1; 2, Alexander I. Shapiro1 1 Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany 2 Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, 120 Ny Munkegade, Building 1520, DK- 8000 Aarhus C, Denmark Received day month year / Accepted day month year ABSTRACT Context. The study of stellar activity cycles is crucial to understand the underlying dynamo and how it causes magnetic activity signatures such as dark spots and bright faculae. Having knowledge about the dominant source of surface activity might allow us to draw conclusions about the star’s age and magnetic field topology, and to put the solar cycle in context. Aims. We investigate the underlying process that causes magnetic activity by studying the appearance of activity signatures in con- temporaneous photometric and chromospheric time series. Methods. Lomb-Scargle periodograms are used to search for cycle periods present in the photometric and chromospheric time series. To emphasize the signature of the activity cycle we account for rotation-induced scatter in both data sets by fitting a quasi-periodic Gaussian process model to each observing season. After subtracting the rotational variability, cycle amplitudes and the phase differ- ence between the two time series are obtained by fitting both time series simultaneously using the same cycle period. Results. We find cycle periods in 27 of the 30 stars in our sample. -
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 .