DOCSLIB.ORG

Kein Folientitel

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Kein Folientitel The Doppler Method, or the Radial Velocity Detection of Planets: II. Results Telescope Instrument Wavelength Reference 1-m MJUO Hercules Th-Ar / Iodine cell 1.2-m Euler Telescope CORALIE Th-Ar 1.8-m BOAO BOES Iodine Cell 1.88-m Okayama Obs, HIDES Iodine Cell 1.88-m OHP SOPHIE Th-Ar 2-m TLS Coude Echelle Iodine Cell 2.2m ESO/MPI La Silla FEROS Th-Ar 2.7m McDonald Obs. 2dcoude Iodine cell 3-m Lick Observatory Hamilton Echelle Iodine cell 3.8-m TNG SARG Iodine Cell 3.9-m AAT UCLES Iodine cell 3.6-m ESO La Silla HARPS Th-Ar 8.2-m Subaru Telescope HDS Iodine Cell 8.2-m VLT UVES Iodine cell 9-m Hobby-Eberly HRS Iodine cell 10-m Keck HiRes Iodine cell Campbell & Walker: The Pioneers of RV Planet Searches 1988: 1980-1992 searched for planets around 26 solar-type stars. Even though they found evidence for planets, they were not 100% convinced. If they had looked at 100 stars they certainly would have found convincing evidence for exoplanets. Campbell, Walker, & Yang 1988 „Probable third body variation of 25 m s–1, 2.7 year period, superposed on a large velocity gradient“ The first (?) extrasolar planet around a normal star: HD 114762 with M sin i = 11 MJ discovered by Latham et al. (1989) Filled circles are data taken at McDonald Observatory using the telluric lines at 6300 Ang. The mass was uncomfortably high (remember sin i effect) to regard it unambiguously as an extrasolar planet The Search For Extrasolar Planets At McDonald Observatory Bill Cochran & Artie Hatzes Hobby-Eberly 9 m Telescope Harlan J. Smith Phillip MacQueen, Paul Robertson, 2001 - present 2.7 m Telescope Erik Brugamyer, Diane Paulson, Robert 1988 - present Robert Wittenmyer, Stuart Barnes Michael Endl 51 Pegasi b: the 1st extrasolar planet: P = 4.3 days!!! a = 0.05 AU !!! M sin i = 0.45 M Jupiter Michel Mayor & Didier Queloz 1995 A HOT JUPITER 1997: The first 2.7 m Survey Planet: P = 2.2 yrs a = 1.67 AU M ~ 1.7 M Jupiter More Planets / Brown Dwarfs (co-)discovered with the 2.7 m Telescope: Eps Eri b: Gam Cep: HD 137510 b: HD 13189 b: Beta Gem b: HD 91699 b: And then the discoveries started rolling in: “New Planet Seen Outside Solar System” New York Times April 19, 1996 “10 More Planets Discovered” Washington Post August 6, 2000 “First new solar system discovered” USA TODAY April 16, 1999 Global Properties of Exoplanets: Mass Distribution The Brown Dwarf Desert Planet: M < 13 MJup → no nuclear burning Brown Dwarf: 13 MJup < M < ~80 MJup → only deuterium burning Star: M > ~80 MJup → Hydrogen burning Up-to-date Histograms with all ~ 500 exoplanets: One argument: Because of unknown sin i these are just low mass stars seen with i near 0 i decreasing probability decreasing Semi-Major Axis Distribution Number Semi-major Axis (AU) The lack of long period planets is a selection effect since these take a long time to detect The short period planets are also a selection effect: they are the easiest to find and now transiting surveys are geared to finding these. Updated: Eccentricity distribution Fall off at high eccentricity may be partially due to an observing bias… e=0.4 e=0.6 e=0.8 ω=0 ω=90 ω=180 …high eccentricity orbits are hard to detect! For very eccentric orbits the value of the eccentricity is is often defined by one data point. If you miss the peak you can get the wrong mass! At opposition with Earth would be 1/5 diameter of full moon, 12x brighter than Venus ε Eri 2 ´´ Comparison of some eccentric orbit planets to our solar system Mass versusEccentricities Orbital Distance There is a relative lack of massive close-in planets Classes of planets: 51 Peg Planets: Jupiter mass planets in short period orbits Discovered by Mayor & Queloz 1995 Classes of planets: 51 Peg Planets • ~35% of known extrasolar planets are 51 Peg planets (selection effect) • 0.5–1% of solar type stars have giant planets in short period orbits • 5–10% of solar type stars have a giant planet (longer periods) Somehow these giant planets ended up very close to the star! => orbital migration Classes of planets: Hot Neptunes Santos et al. 2004 Butler et al. 2004 M sin i = 14-20 MEarth If there are „hot Jupiters“ and „hot Neptunes“ it makes sense that there are „hot Superearths“ CoRoT-7b Mass = 7.4 ME P = 0.85 d Classes: The Massive Eccentrics • Masses between 7–20 MJupiter • Eccentricities, e > 0.3 • Prototype: HD 114762 discovered in 1989! m sini = 11 MJup Classes: The Massive Eccentrics There are no massive planets in circular orbits Planet-Planet Interactions Initially you have two giant planets in circular orbits These interact gravitationally. One is ejected and the remaining planet is in an eccentric orbit Lin & Ida, 1997, Astrophysical Journal, 477, 781L Red: Planets with masses < 4 MJup Blue: Planets with masses > 4 MJup Planets in Binary Systems Why should we care about binary stars? • Most stars are found in binary systems • Does binary star formation prevent planet formation? • Do planets in binaries have different characteristics? • For what range of binary periods are planets found? • What conditions make it conducive to form planets? (Nurture versus Nature?) • Are there circumbinary planets? Some Planets in known Binary Systems: Star a (AU) 16 Cyg B 800 55 CnC 540 HD 46375 300 τ Boo 155 υ And 1540 HD 222582 4740 HD 195019 3300 There are very few planets in close binaries. One exception is the γ Cep system. The first extra-solar Planet may have been found by Walker et al. in 1992 in a binary system: Ca II is a measure of stellar activity (spots) γ Cephei Binary Period 56.8 ± 5 Years Msini ~ 0,4 ± 0,1 MSun e 0,42 ± 0,04 a 18.5 AU K 1,98 ± 0,08 km/s Planet Period 2,47 Years Msini 1,76 MJupiter e 0,2 a 2,13 AU K 26,2 m/s γ Cephei Primary star (A) Secondary Star (B) Planet (b) The planet around γ Cep is difficult to form and on the borderline of being impossible. Standard planet formation theory: Giant planets form beyond the snowline where the solid core can form. Once the core is formed the protoplanet accretes gas. It then migrates inwards. In binary systems the companion truncates the disk. In the case of γ Cep this disk is truncated just at the ice line. No ice line, no solid core, no giant planet to migrate inward. γ Cep can just be formed, a giant planet in a shorter period orbit would be problems for planet formation theory. The interesting Case of 16 Cyg B These stars are identical and are „solar twins“. 16 Cyg B has a giant planet with 1.7 MJup in a 800 d period, but star A shows no evidence for any planet. Why? Planetary Systems: ~50 Multiple Systems Extrasolar Planetary Systems (18 shown) Star P (d) MJsini a (AU) e HD 82943 221 0.9 0.7 0.54 Star P (d) MJsini a (AU) e 444 1.6 1.2 0.41 HD 74156 51.6 1.5 0.3 0.65 GL 876 30 0.6 0.1 0.27 2300 7.5 3.5 0.40 61 2.0 0.2 0.10 HD 169830 229 2.9 0.8 0.31 47 UMa 1095 2.4 2.1 0.06 2102 4.0 3.6 0.33 2594 0.8 3.7 0.00 HD 160691 9.5 0.04 0.09 0 HD 37124 153 0.9 0.5 0.20 637 1.7 1.5 0.31 550 1.0 2.5 0.40 2986 3.1 0.09 0.80 55 CnC 2.8 0.04 0.04 0.17 HD 12661 263 2.3 0.8 0.35 14.6 0.8 0.1 0.0 1444 1.6 2.6 0.20 44.3 0.2 0.2 0.34 HD 168443 58 7.6 0.3 0.53 260 0.14 0.78 0.2 5300 4.3 6.0 0.16 1770 17.0 2.9 0.20 HD 38529 14.31 0.8 0.1 0.28 Ups And 4.6 0.7 0.06 0.01 2207 12.8 3.7 0.33 241.2 2.1 0.8 0.28 1266 4.6 2.5 0.27 HD 190360 17.1 0.06 0.13 0.01 2891 1.5 3.92 0.36 HD 108874 395.4 1.36 1.05 0.07 HD 202206 255.9 17.4 0.83 0.44 1605.8 1.02 2.68 0.25 1383.4 2.4 2.55 0.27 HD 128311 448.6 2.18 1.1 0.25 HD 11964 37.8 0.11 0.23 0.15 919 3.21 1.76 0.17 1940 0.7 3.17 0.3 HD 217107 7.1 1.37 0.07 0.13 3150 2.1 4.3 0.55 The 5-planet System around 55 CnC 0.17MJ 5.77 M J • 0.82M J 0.03M •0.11 MJ • J Red lines: solar system plane orbits The Planetary System around GJ 581 (M dwarf!) 16 ME 7.2 ME 5.5 ME Inner planet M sin i = 1.9 MEarth Resonant Systems Systems Star P (d) MJsini a (AU) e HD 82943 221 0.9 0.7 0.54 → 2:1 444 1.6 1.2 0.41 GL 876 30 0.6 0.1 0.27 → 2:1 61 2.0 0.2 0.10 55 Cnc 14.6 0.8 0.1 0.0 → 3:1 44.3 0.2 0.2 0.34 HD 108874 395.4 1.36 1.05 0.07 → 4:1 1605.8 1.02 2.68 0.25 HD 128311 448.6 2.18 1.1 0.25 → 2:1 919 3.21 1.76 0.17 2:1 → Inner planet makes two orbits for every one of the outer planet Eccentricities • Period (days) Red points: Systems Blue points: single planets Mass versus Orbital Distance Eccentricities Red points: Systems Blue points: single planets On average, giant planets in planetary sytems tend to be lighter than single planets.
Load more

Recommended publications
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Annual Report 2005
    Max Planck Institute t für Astron itu o st m n ie -I k H c e n id la e l P b - e x r a g M M g for Astronomy a r x e b P l la e n id The Max Planck Society c e k H In y s m titu no Heidelberg-Königstuhl te for Astro The Max Planck Society for the Promotion of Sciences was founded in 1948. It operates at present 88 Institutes and other facilities dedicated to basic and applied research. With an annual budget of around 1.4 billion € in the year 2005, the Max Planck Society has about 12 400 employees, of which 4300 are scientists. In addition, annually about 11000 junior and visiting scientists are working at the Institutes of the Max Planck Society. The goal of the Max Planck Society is to promote centers of excellence at the fore- front of the international scientific research. To this end, the Institutes of the Society are equipped with adequate tools and put into the hands of outstanding scientists, who Annual Report have a high degree of autonomy in their scientific work. 2005 Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. 2005 Public Relations Office Hofgartenstr. 8 80539 München Tel.: 089/2108-1275 or -1277 Annual Report Fax: 089/2108-1207 Internet: www.mpg.de Max Planck Institute for Astronomie K 4242 K 4243 Dossenheim B 3 D o s s E 35 e n h e N i eckar A5 m e r L a n d L 531 s t r M a a ß nn e he im B e e r r S t tr a a - K 9700 ß B e e n z - S t r a ß e Ziegelhausen Wieblingen Handschuhsheim K 9702 St eu b A656 e n s t B 37 r a E 35 ß e B e In de A5 r r N l kar ec i c M Ne k K 9702 n e a Ruprecht-Karls- ß lierb rh
    [Show full text]
  • Jjmonl 1603.Pmd
    alactic Observer GJohn J. McCarthy Observatory Volume 9, No. 3 March 2016 GRAIL - On the Trail of the Moon's Missing Mass GRAIL (Gravity Recovery and Interior Laboratory) was a NASA scientific mission in 2011/12 to map the surface of the moon and collect data on gravitational anomalies. The image here is an artist's impres- sion of the twin satellites (Ebb and Flow) orbiting in tandem above a gravitational image of the moon. See inside, page 4 for information on gravitational anomalies (mascons) or visit http://solarsystem. nasa.gov/grail. The John J. McCarthy Observatory Galactic Observer New Milford High School Editorial Committee 388 Danbury Road Managing Editor New Milford, CT 06776 Bill Cloutier Phone/Voice: (860) 210-4117 Production & Design Phone/Fax: (860) 354-1595 www.mccarthyobservatory.org Allan Ostergren Website Development JJMO Staff Marc Polansky It is through their efforts that the McCarthy Observatory Technical Support has established itself as a significant educational and Bob Lambert recreational resource within the western Connecticut Dr. Parker Moreland community. Steve Barone Jim Johnstone Colin Campbell Carly KleinStern Dennis Cartolano Bob Lambert Mike Chiarella Roger Moore Route Jeff Chodak Parker Moreland, PhD Bill Cloutier Allan Ostergren Cecilia Dietrich Marc Polansky Dirk Feather Joe Privitera Randy Fender Monty Robson Randy Finden Don Ross John Gebauer Gene Schilling Elaine Green Katie Shusdock Tina Hartzell Paul Woodell Tom Heydenburg Amy Ziffer In This Issue "OUT THE WINDOW ON YOUR LEFT" ............................... 4 SUNRISE AND SUNSET ...................................................... 13 MARE HUMBOLDTIANIUM AND THE NORTHEAST LIMB ......... 5 JUPITER AND ITS MOONS ................................................. 13 ONE YEAR IN SPACE ....................................................... 6 TRANSIT OF JUPITER'S RED SPOT ....................................
    [Show full text]
  • 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,
    [Show full text]
  • Interstellarum 25 Schließen Wir Den Ersten Jahrgang Der Neuen Interstellarum-Hefte Ab
    Liebe Leserinnen, liebe Leser, Meade gegen Celestron, das ist das große Duell der beiden Teleskopgiganten aus Amerika. Wir sind stolz darauf, als erste deutschsprachige Zeitschrift einen fairen Zweikampf der weltgröß- ten Fernrohrhersteller anbieten zu können; un- getrübt von wirtschaftlichen oder redaktionellen Vorbehalten. Dazu haben wir die neuen aufre- genden GPS-Teleskope von Meade und Celes- tron in einem Produktvergleich gegenüberge- stellt. Im ersten Teil in diesem Heft erfahren Sie mehr über Mechanik und Elektronik der beiden Computerteleskope (Seite 60); die Ergebnisse der Praxis unter den Sternen lesen Sie dann in einem kommenden Heft. Mit interstellarum 25 schließen wir den ersten Jahrgang der neuen interstellarum-Hefte ab. Ein Plus von 30% bei den Abonnentenzahlen spricht für unseren Weg, den wir konsequent fortsetzen Polarlichter in Deutschland (Foto: Thomas Jäger) werden. Dabei möchten wir verstärkt das Augen- merk auf hochqualitative Beiträge für praktisch tätige Amateurastronomen lenken. werden wir uns zusätzlich der Jupiterbeobach- tung und dem Merkurdurchgang vom 7.5.2003 2003 wird bei interstellarum zum Jahr der widmen. Schließlich stehen 2003 mit zwei Planetenbeobachtung ernannt. Auftakt ist der Mondfinsternissen und einer partiellen Sonnen- Beitrag zur Beobachtung der Saturnringe in die- finsternis drei weitere Großereignisse auf dem ser Ausgabe (Seite 34). Mit dem nächsten Heft Programm. beginnen wir zusätzlich eine intensive Vorberei- tung auf die große Mars-Opposition in diesem Was wir noch 2003 geplant haben, ist auf Sommer mit Beiträgen zu verschiedenen prakti- www.interstellarum.de nachzulesen. Ihren eige- schen Themenkreisen in jedem Heft. Verstärkt nen Bericht nehmen wir gerne entgegen. Mit interstellarum 25 endet die Comic-Serie Astromax (Seite 80), die Schöpfer Rainer Töpler aus Zeitgründen aufgeben muss – vielen Dank für die sechs kurzweiligen Geschichtchen.
    [Show full text]
  • A Search for Variability and Transit Signatures In
    A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA A thesis presented to the faculty of 3 ^ San Francisco State University Zo\% In partial fulfilment of W* The Requirements for The Degree Master of Science In Physics: Astronomy by Badrinath Thirumalachari San JVancisco, California December 2018 Copyright by Badrinath Thirumalachari 2018 CERTIFICATION OF APPROVAL I certify that I have read A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA by Badrinath Thirumalachari and that in my opinion this work meets the criteria for approving a thesis submitted in partial fulfillment of the requirements for the degree: Master of Science in Physics: Astronomy at San Francisco State University. fov- Dr. Stephen Kane, Ph.D. Astrophysics Associate Professor of Planetary Astrophysics Dr. Uo&eph Barranco, Ph.D. .%trtJphysics Chairfe Associate Professor of Physics K + A Q , L a . Dr. Ron Marzke, Ph.D. Astronomy Assoc. Dean of College of Science & Engineering A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA Badrinath Thirumalachari San Francisco State University 2018 The study and characterization of exoplanets has picked up pace rapidly over the past few decades with the invention of newer techniques and instruments. Detecting transits in stellar photometric data around stars already known to harbor exoplanets is crucial for exoplanet characterization. Due to these advancements we now have oceans of data and coming up with an automated way of performing exoplanet characterization is a challenge. In this thesis I describe one such method to search for transits in Hipparcos dataset containing photometric data for over 118000 stars. The radial velocity method has discovered a lot of planets around bright host stars and a follow up transit detection will give us the density of the exoplanet.
    [Show full text]
  • Other Planetary Systems
    ffiffi PIaffiffi*mffiW Syst€il?'es R.Paul Butler oDERNAsrRoNoMy nEvEALsto us, for the first time in his_ tory, scenesfrom one end ofthe cosmosto theother. 377 We havepicturesque views of planetarysurfaces in our own solarsystem - asthis book amply demonstrates I I - and panoramasof adolescentdeep-field galaxies swarming near the limit of the observableuniverse . Beyond pro- viding pretty pictures, asronomy pracesour worrd and our brief human livesin their true conrexrs:as vanishingly tiny subplotsin a truly enormous cosmicplay. The curtain op*, *iri, a Big Bang synthesisof the chemicalelembnts that evenruallylead to self- replicating, competitivestructures of moleculeswe call *life.,, While we humans play out our brief bit parts, we yearn ro grasp the overall plot. Naturally we wonder whether there are worrds beyond those of our solarsystem. Are they numerousor rare? How many of thcm haveconditions ripe for biologyf These are not new questions. _ In the fourth century BC, the Greek philosopher Epicurus spoke boldly of the infinite worlds that logrcally ,.aroms,, followed from the infinite number of thar he postulated. His contemporary,Aristotle, differed, seeing Earth asthe unique center ofa perfect crystallinesky. Aristotle,s Earth-centered cosmosdominated Westernthought for more than 1,500 years.The notion ofotherworlds took hold "gain on\ after Copernicusyanked Earth from its centralposition and placed it in orbit around rhe Sun with other planets. A computer simulates the birth of a Soon lupitcr-size planet around various thinkers another star. realizedthat the starsmight be diirant sunsand thercfore might haveplanets of their own. For centuries thereafter, detecting these extrasolar plenet! seemed beyond all possibility. Shining by reflected light, such objects should be roughly a billion times (perhap s 22 to 25 magnitudes) fainter than their host stars.
    [Show full text]
  • 2016 Publication Year 2021-04-23T14:32:39Z Acceptance in OA@INAF Age Consistency Between Exoplanet Hosts and Field Stars Title B
    Publication Year 2016 Acceptance in OA@INAF 2021-04-23T14:32:39Z Title Age consistency between exoplanet hosts and field stars Authors Bonfanti, A.; Ortolani, S.; NASCIMBENI, VALERIO DOI 10.1051/0004-6361/201527297 Handle http://hdl.handle.net/20.500.12386/30887 Journal ASTRONOMY & ASTROPHYSICS Number 585 A&A 585, A5 (2016) Astronomy DOI: 10.1051/0004-6361/201527297 & c ESO 2015 Astrophysics Age consistency between exoplanet hosts and field stars A. Bonfanti1;2, S. Ortolani1;2, and V. Nascimbeni2 1 Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy e-mail: [email protected] 2 Osservatorio Astronomico di Padova, INAF, Vicolo dell’Osservatorio 5, 35122 Padova, Italy Received 2 September 2015 / Accepted 3 November 2015 ABSTRACT Context. Transiting planets around stars are discovered mostly through photometric surveys. Unlike radial velocity surveys, photo- metric surveys do not tend to target slow rotators, inactive or metal-rich stars. Nevertheless, we suspect that observational biases could also impact transiting-planet hosts. Aims. This paper aims to evaluate how selection effects reflect on the evolutionary stage of both a limited sample of transiting-planet host stars (TPH) and a wider sample of planet-hosting stars detected through radial velocity analysis. Then, thanks to uniform deriva- tion of stellar ages, a homogeneous comparison between exoplanet hosts and field star age distributions is developed. Methods. Stellar parameters have been computed through our custom-developed isochrone placement algorithm, according to Padova evolutionary models. The notable aspects of our algorithm include the treatment of element diffusion, activity checks in terms of 0 log RHK and v sin i, and the evaluation of the stellar evolutionary speed in the Hertzsprung-Russel diagram in order to better constrain age.
    [Show full text]
  • SILICON and OXYGEN ABUNDANCES in PLANET-HOST STARS Erik Brugamyer, Sarah E
    The Astrophysical Journal, 738:97 (11pp), 2011 September 1 doi:10.1088/0004-637X/738/1/97 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. SILICON AND OXYGEN ABUNDANCES IN PLANET-HOST STARS Erik Brugamyer, Sarah E. Dodson-Robinson, William D. Cochran, and Christopher Sneden Department of Astronomy and McDonald Observatory, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712, USA; [email protected] Received 2011 February 4; accepted 2011 June 22; published 2011 August 16 ABSTRACT The positive correlation between planet detection rate and host star iron abundance lends strong support to the core accretion theory of planet formation. However, iron is not the most significant mass contributor to the cores of giant planets. Since giant planet cores are thought to grow from silicate grains with icy mantles, the likelihood of gas giant formation should depend heavily on the oxygen and silicon abundance of the planet formation environment. Here we compare the silicon and oxygen abundances of a set of 76 planet hosts and a control sample of 80 metal-rich stars without any known giant planets. Our new, independent analysis was conducted using high resolution, high signal-to-noise data obtained at McDonald Observatory. Because we do not wish to simply reproduce the known planet–metallicity correlation, we have devised a statistical method for matching the underlying [Fe/H] distributions of our two sets of stars. We find a 99% probability that planet detection rate depends on the silicon abundance of the host star, over and above the observed planet–metallicity correlation.
    [Show full text]
  • AMD-Stability and the Classification of Planetary Systems
    A&A 605, A72 (2017) DOI: 10.1051/0004-6361/201630022 Astronomy c ESO 2017 Astrophysics& AMD-stability and the classification of planetary systems? J. Laskar and A. C. Petit ASD/IMCCE, CNRS-UMR 8028, Observatoire de Paris, PSL, UPMC, 77 Avenue Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] Received 7 November 2016 / Accepted 23 January 2017 ABSTRACT We present here in full detail the evolution of the angular momentum deficit (AMD) during collisions as it was described in Laskar (2000, Phys. Rev. Lett., 84, 3240). Since then, the AMD has been revealed to be a key parameter for the understanding of the outcome of planetary formation models. We define here the AMD-stability criterion that can be easily verified on a newly discovered planetary system. We show how AMD-stability can be used to establish a classification of the multiplanet systems in order to exhibit the planetary systems that are long-term stable because they are AMD-stable, and those that are AMD-unstable which then require some additional dynamical studies to conclude on their stability. The AMD-stability classification is applied to the 131 multiplanet systems from The Extrasolar Planet Encyclopaedia database for which the orbital elements are sufficiently well known. Key words. chaos – celestial mechanics – planets and satellites: dynamical evolution and stability – planets and satellites: formation – planets and satellites: general 1. Introduction motion resonances (MMR, Wisdom 1980; Deck et al. 2013; Ramos et al. 2015) could justify the Hill-type criteria, but the The increasing number of planetary systems has made it nec- results on the overlap of the MMR island are valid only for close essary to search for a possible classification of these planetary orbits and for short-term stability.
    [Show full text]
  • Search for Brown-Dwarf Companions of Stars⋆⋆⋆
    A&A 525, A95 (2011) Astronomy DOI: 10.1051/0004-6361/201015427 & c ESO 2010 Astrophysics Search for brown-dwarf companions of stars, J. Sahlmann1,2, D. Ségransan1,D.Queloz1,S.Udry1,N.C.Santos3,4, M. Marmier1,M.Mayor1, D. Naef1,F.Pepe1, and S. Zucker5 1 Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland e-mail: [email protected] 2 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany 3 Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal 4 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Portugal 5 Department of Geophysics and Planetary Sciences, Tel Aviv University, Tel Aviv 69978, Israel Received 19 July 2010 / Accepted 23 September 2010 ABSTRACT Context. The frequency of brown-dwarf companions in close orbit around Sun-like stars is low compared to the frequency of plane- tary and stellar companions. There is presently no comprehensive explanation of this lack of brown-dwarf companions. Aims. By combining the orbital solutions obtained from stellar radial-velocity curves and Hipparcos astrometric measurements, we attempt to determine the orbit inclinations and therefore the masses of the orbiting companions. By determining the masses of poten- tial brown-dwarf companions, we improve our knowledge of the companion mass-function. Methods. The radial-velocity solutions revealing potential brown-dwarf companions are obtained for stars from the CORALIE and HARPS planet-search surveys or from the literature. The best Keplerian fit to our radial-velocity measurements is found using the Levenberg-Marquardt method.
    [Show full text]