DOCSLIB.ORG

THE DISTANCE to the YOUNG EXOPLANET 2M1207 B in the TW HYA ASSOCIATION. E. E. Mamajek, Harvard- Smithsonian Center for Astrophys

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
THE DISTANCE to the YOUNG EXOPLANET 2M1207 B in the TW HYA ASSOCIATION. E. E. Mamajek, Harvard- Smithsonian Center for Astrophys Protostars and Planets V 2005 8522.pdf THE DISTANCE TO THE YOUNG EXOPLANET 2M1207 B IN THE TW HYA ASSOCIATION. E. E. Mamajek, Harvard- Smithsonian Center for Astrophysics, 60 Garden St., MS-42, Cambridge MA 02138, USA, ([email protected]). Introduction: Results: Recently, a faint companion to the young brown dwarf ² The proper motion and radial velocity of 2M1207 are statisti- 2MASSW J1207334-393254 (2M1207) was imaged [1], and cally consistent with TWAmembership (quantitatively strength- found to have common proper motion with its primary [2]. ening claims by [1,4]). The brown dwarf and companion are purported to be members ² The moving cluster method predicts a distance of 53 § 6 pc of the »10 Myr-old TW Hya Association (TWA) [3,4]. As- to the 2M1207 system. suming a distance of 70 § 20 pc and age of 10 Myr, the brown ² The improved distance roughly halves the previously cal- dwarf and companion are consistent with masses of »25 MJup culated luminosities for 2M1207 A and B, and reduces their » » and »5 MJup [1]. There is currently little constraint on the inferred masses to 21 MJup and 3 MJup using modern distance to this astrophysically interesting system (with the evolutionary tracks [9]. The current projected separation be- secondary possibly being the first imaged extrasolar planet). tween A and B is 41 § 5 AU. Although a trigonometric parallax is not yet available, it is pos- ² Objects in the literature with the “TWA” acronym seem to sible to use the proper motion and putative cluster membership be segregated by distance into at least two groups, with TWA of the 2M1207 system to estimate the distance using the mov- 12, 17, 18, 19, 24 appearing to be more distant (d ' 100- ing cluster method. This technique was historically valuable 150 pc) members of the Lower Cen-Cru OB association. The for establishing the bottom rungs of the cosmic distance ladder remaining TWA objects have moving cluster distances of d = in the pre-Hipparcos era, through geometrically determining 49 § 12 pc (1). the distances to members of nearby clusters (e.g. Hyades). ² The proper motion data for TWA are consistent with an +0:3 ¡1 In this poster contribution, I (1) improve the kinematic internal 1D velocity dispersion of 0:8¡0:2 km s . model and membership for the TWA,(2) calculate an improved ² There is some evidence for expansion in the TWA. This proper motion for the 2M1207 system, (3) test 2M1207’s mem- analysis places a strong lower limit on the linear expansion bership to the TWA, (4) use the moving cluster method to age of the TWA(>10.4 Myr; 95% confidence). Higher qual- estimate the distance to the 2M1207 system and other TWA ity radial velocities and trigonometric parallaxes are needed to members, (5) investigate the relation between the TWA and further constrain if, and how fast, TWA is expanding. the Lower Centaurus-Crux OB association, and (6) estimate ² A previously published expansion age estimate for TWA by the expansion age of the TWA. The results from this poster [10] (8.3 Myr), can be statistically ruled out. will appear in upcoming ApJ paper [5]. ² A kinematic analysis of B- and A-type stars in the Hippar- cos catalog within a 15± radius of the TWA center identified Analysis only one new TWA candidate: HIP 54477 (A1V). Further Members of a moving group, whose motions reflect either observations (radial velocity measurements, search for Li-rich parallel motion, expansion, or contraction, will have proper companions) should be undertaken to confirm or reject its TWA motions which appear to converge to a point on the sky. The membership. Other than the famous debris disk star HR 4796 positions and proper motions of candidate members of a mov- (TWA 11; A0V), and possibly HIP 54477, there is no other ing group can be used, in conjunction with some combination evidence for other high mass B- or A-type members of TWA. of available parallax and/or radial velocity data, to determine the space velocity of the group, as well as test for expan- Acknowledgments: EM is supported by a Clay Postdoctoral sion/contraction. Using the most recent TWA membership Fellowship from the Smithsonian Astrophysical Observatory list [6], along with astrometric data from the literature, and (SAO). new proper motions calculated by the author, I estimated the TWA convergent point using a Â2 minimization grid technique References: (similar to that of [7,8]). With a convergent point solution, the [1] Chauvin, G., et al. 2004, A&A, 425, L29; [2] Chau- stellar proper motions can be used to estimate individual dis- vin, G., et al. 2005, A&A, 438, L25; [3] Webb, R. A., et al. tances to each TWA member. As a check, the moving cluster 1999, ApJ, 512, L63; [4] Gizis, J. E. 2002, ApJ, 575, 484; [5] distances can be compared to trigonometric parallax distances Mamajek, E. E. 2005, ApJ, in press (astro-ph/0507416); [6] (when available), and the predicted moving cluster radial ve- Zuckerman, B., & Song, I. 2004, ARA&A, 42, 685; [7] Jones, locities can be compared to measured values. D. H. P. 1971, MNRAS, 152, 231; [8] de Bruijne, J. H. J. 1999, MNRAS, 306, 381; [9] Baraffe, I., et al. 2003, A&A 402, 701; [10] Makarov, V. V., & Fabricius, C. 2001, A&A, 368, 866;.
Load more

Recommended publications
  • Arxiv:1910.11169V1 [Astro-Ph.EP] 24 Oct 2019 Metchev Et Al.(2004) Due to the Detection of a Strong Mid- Tinuum and at HCO+ and CO Gas Emission Lines
    Astronomy & Astrophysics manuscript no. PDS70_v2 c ESO 2019 October 25, 2019 VLT/SPHERE exploration of the young multiplanetary system PDS70? D. Mesa1, M. Keppler2, F. Cantalloube2, L. Rodet3, B. Charnay4, R. Gratton1, M. Langlois5; 6, A. Boccaletti4, M. Bonnefoy3, A. Vigan6, O. Flasseur7, J. Bae8, M. Benisty3; 9, G. Chauvin3; 9, J. de Boer10, S. Desidera1, T. Henning2, A.-M. Lagrange3, M. Meyer11, J. Milli12, A. Müller2, B. Pairet13, A. Zurlo14; 15; 6, S. Antoniucci16, J.-L. Baudino17, S. Brown Sevilla2, E. Cascone18, A. Cheetham19, R.U. Claudi1, P. Delorme3, V. D’Orazi1, M. Feldt2, J. Hagelberg19, M. Janson20, Q. Kral4, E. Lagadec21, C. Lazzoni1, R. Ligi22, A.-L. Maire2; 23, P. Martinez21, F. Menard3, N. Meunier3, C. Perrot4; 24; 25, S. Petrus3, C. Pinte26; 3, E.L. Rickman19, S. Rochat3, D. Rouan4, M. Samland2; 20, J.-F. Sauvage27; 6, T. Schmidt4; 28, S. Udry19, L. Weber19, F. Wildi19 (Affiliations can be found after the references) Received / accepted ABSTRACT Context. PDS 70 is a young (5.4 Myr), nearby (∼113 pc) star hosting a known transition disk with a large gap. Recent observations with SPHERE and NACO in the near-infrared (NIR) allowed us to detect a planetary mass companion, PDS 70 b, within the disk cavity. Moreover, observations in Hα with MagAO and MUSE revealed emission associated to PDS 70 b and to another new companion candidate, PDS 70 c, at a larger separation from the star. PDS 70 is the only multiple planetary system at its formation stage detected so far through direct imaging. Aims. Our aim is to confirm the discovery of the second planet PDS 70 c using SPHERE at VLT, to further characterize its physical properties, and search for additional point sources in this young planetary system.
    [Show full text]
  • 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]
  • The Nearest Stars: a Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific
    www.astrosociety.org/uitc No. 5 - Spring 1986 © 1986, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. The Nearest Stars: A Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific A tour through our stellar neighborhood As evening twilight fades during April and early May, a brilliant, blue-white star can be seen low in the sky toward the southwest. That star is called Sirius, and it is the brightest star in Earth's nighttime sky. Sirius looks so bright in part because it is a relatively powerful light producer; if our Sun were suddenly replaced by Sirius, our daylight on Earth would be more than 20 times as bright as it is now! But the other reason Sirius is so brilliant in our nighttime sky is that it is so close; Sirius is the nearest neighbor star to the Sun that can be seen with the unaided eye from the Northern Hemisphere. "Close'' in the interstellar realm, though, is a very relative term. If you were to model the Sun as a basketball, then our planet Earth would be about the size of an apple seed 30 yards away from it — and even the nearest other star (alpha Centauri, visible from the Southern Hemisphere) would be 6,000 miles away. Distances among the stars are so large that it is helpful to express them using the light-year — the distance light travels in one year — as a measuring unit. In this way of expressing distances, alpha Centauri is about four light-years away, and Sirius is about eight and a half light- years distant.
    [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]
  • The Radio Continuum View of Centaurus Acentaurus A
    TheThe radioradio continuumcontinuum viewview ofof CentaurusCentaurus AA Ron Ekers CSIRO The Many Faces of Centaurus A Sydney, 29 June 2009 Ilana's composite Morganti et al. 1999 9° 10' Burns et al. xx image courtesy Norbert Junkes (MPIfR) WhyWhy CentaurusCentaurus AA isis specialspecial ■ the first extragalactic radio source ■ the brightest source in the Southern Hemisphere ■ the second double lobed source discovered ± after Cygnus A ■ the closest Radio Galaxy ■ the closest AGN ■ the closest SMBH ± VLBI resolution 0.01pc, 100 Rs ■ A spectacular galaxy EvolutionEvolution ofof thethe ModelsModels ■ Radio sources ± Static magnetic field 1960 ± Evolutionary sequence 1970 ± Continuous injection ± Continuous reacceleration ■ Energy source ± Galaxy collisions 1950's ± Nuclear accretions 1960- ± Accretion triggered by collisions 1980- CentaurusCentaurus AA thethe closestclosest AGNAGN ■ Distance 3.4Mpc ■ Next closest comparable AGN M87 17Mpc ! ■ Average distance to a L=1024 W Hz-1 radio galaxies ± 10Mpc ± So we are lucky (or influenced!) ■ Much easier to study at all wavelengths ■ Subtends a large angular size ± Good linear resolution ± Background probes SomeSome RadioRadio GalaxiesGalaxies Name Size Log Log (kpc) Luminosity Energy (ergs sec-1) (ergs) Centaurus A 470 41.7 59.9 Cygnus A 200 45.2 60.6 M87 80 42.0 58.6 M82 1 39.5 55.2 PolarizationPolarization inin CentaurusCentaurus AA Bracewell 1962 ■ April 1962 ■ Parkes 64m just completed ■ Discovered by Bracewell ± Published Cooper and Price ± Visitors Log ± Not a National Facilities yet! ■ Connie
    [Show full text]
  • TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-Like Star HD 108236
    Swarthmore College Works Physics & Astronomy Faculty Works Physics & Astronomy 2-1-2021 TESS Discovery Of A Super-Earth And Three Sub-Neptunes Hosted By The Bright, Sun-Like Star HD 108236 T. Daylan K. Pinglé J. Wright M. N. Günther K. G. Stassun Follow this and additional works at: https://works.swarthmore.edu/fac-physics See P nextart of page the forAstr additionalophysics andauthors Astr onomy Commons Let us know how access to these works benefits ouy Recommended Citation T. Daylan, K. Pinglé, J. Wright, M. N. Günther, K. G. Stassun, S. R. Kane, A. Vanderburg, D. Jontof-Hutter, J. E. Rodriguez, A. Shporer, C. X. Huang, T. Mikal-Evans, M. Badenas-Agusti, K. A. Collins, B. V. Rackham, S. N. Quinn, R. Cloutier, K. I. Collins, P. Guerra, Eric L.N. Jensen, J. F. Kielkopf, B. Massey, R. P. Schwarz, D. Charbonneau, J. J. Lissauer, J. M. Irwin, Ö Baştürk, B. Fulton, A. Soubkiou, B. Zouhair, S. B. Howell, C. Ziegler, C. Briceño, N. Law, A. W. Mann, N. Scott, E. Furlan, D. R. Ciardi, R. Matson, C. Hellier, D. R. Anderson, R. P. Butler, J. D. Crane, J. K. Teske, S. A. Shectman, M. H. Kristiansen, I. A. Terentev, H. M. Schwengeler, G. R. Ricker, R. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, Z. K. Berta-Thompson, L. G. Bouma, W. Fong, G. Furesz, C. E. Henze, E. H. Morgan, E. Quintana, E. B. Ting, and J. D. Twicken. (2021). "TESS Discovery Of A Super-Earth And Three Sub-Neptunes Hosted By The Bright, Sun-Like Star HD 108236".
    [Show full text]
  • Gli Ammassi Di Galassie
    Universo in Fiore 2017 CORSO BASE I GIGANTI DEL COSMO: GLI AMMASSI DI GALASSIE Sabrina De Grandi [email protected] Organizzazione spaziale delle galassie Ammassi Gruppi Galassie 100 mila a.l. ~30 kpc 3 milioni a.l. ~ 103 kpc 20 milioni a.l. ~ 7x103 kpc I primi cataloghi di ammassi Fino agli anni ’80: ispezione visuale di lastre fotografiche alla ricerca di sovradensita` di galassie. Es. di lastre fotografiche: • PSS: National Geographic Society-Palomar Observatory Sky Survey (Telescopio 5m Hale, Mt. Wilson US) • UKST: Schmidt telescope IIIa-J plates (Telescopio 1.2m, UK-Australia),… I cataloghi di Abell (1958) e Zwicky (1961-1968) Il catalogo piu` usato: Abell (1958) Emisfero Nord (2712) e A.C.O. (1989) Emisfero Sud (1364). 1958: Abell ispeziono` di 104 deg2 di lastre PSS (Luna ~0.25 deg2) Criteri principali: • almeno 30 galassie • compatto (0.02<z<0.2) • piano galattico escluso Dagli anni ’90: • algoritmi automatici di identificazione al posto dell’occhio umano. • Non più lastre fotografiche, ma immagini digitali (CCD) • SDSS (Sloan Digital Sky Survey), iniziata nel 2000 e tutt’ora in atto (35% del cielo osservato, 500 milioni di oggetti, catalogo di ammassi • Accesso libero ai dati (nel Telescopio dedicato ad 2015: 13o Data Release) Apache Point 2.5m (US) Immagine SDSS dell’ammasso A2142 MACS J1206.2-0847 DIAMETRO tipico di un ammasso di galassie ~ 20 milioni anni luce ~ 7 Mpc SPICA (훼 costellazione della Vergine) MACS J1206.2-0847 DIAMETRO tipico di un ammasso di galassie ~ 20 milioni anni luce ~ 7 Mpc ma… DISTANZA di MACS J1206 ~ 4.5 miliardi di anni luce ~ 1500 Mpc Dove si trova la Via Lattea in questa struttura universale? ovvero Noi ci troviamo in un Ammasso di galassie? Il Gruppo Locale 100.000 a.l.
    [Show full text]
  • The Sky This Week
    The sky this week April 20 to April 26, 2020 By Joe Grida, Technical Informaon Officer, ASSA ([email protected]) elcome to the fourth edion of The Sky this Week. It is designed to keep you looking up during these rather uncertain mes. We can’t get together for Members’ Viewing Nights, so I thought I’d write this W to give you some ideas of observing targets that you can chase on any clear night this coming week. As I said in my recent Starwatch* column in The Adverser newspaper: “Even with the restricons in place, stargazing is something that you can do easily on your own. It helps to relieve stress and will keep your sense of perspecve. It’s prey hard to walk away from a night under the stars without a jusfiable sense of awe. And also without sensing a real, albeit tenuous, connecon with the cosmos at large”. * Published on the last Friday of each month Naked eye star walk Over in the eastern late evening sky, Scorpius, the Scorpion (one of the few constellaons in our sky that actually resembles what it is supposed to represent) is difficult to miss. He will keep us company over the coming chilly winter months. Its brightest star, Antares, is a huge star of gargantuan proporons. If we replaced our Sun with it, then all the planets from Mercury through to Jupiter would all find themselves engulfed within it! Just below the tail of Scorpius, you can find the star clusters designated M6 and M7. Take the trouble to observe these with binoculars.
    [Show full text]
  • A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
    geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3].
    [Show full text]
  • Observing Exoplanets
    Observing Exoplanets Olivier Guyon University of Arizona Astrobiology Center, National Institutes for Natural Sciences (NINS) Subaru Telescope, National Astronomical Observatory of Japan, National Institutes for Natural Sciences (NINS) Nov 29, 2017 My Background Astronomer / Optical scientist at University of Arizona and Subaru Telescope (National Astronomical Observatory of Japan, Telescope located in Hawaii) I develop instrumentation to find and study exoplanet, for ground-based telescopes and space missions My interest is focused on habitable planets and search for life outside our solar system At Subaru Telescope, I lead the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument. 2 ALL known Planets until 1989 Approximately 10% of stars have a potentially habitable planet 200 billion stars in our galaxy → approximately 20 billion habitable planets Imagine 200 explorers, each spending 20s on each habitable planet, 24hr a day, 7 days a week. It would take >60yr to explore all habitable planets in our galaxy alone. x 100,000,000,000 galaxies in the observable universe Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L. For constant stellar flux, distance to star scales as L1/2 Examples: Sun → habitable zone is at ~1 AU Rigel (B type star) Proxima Centauri (M type star) Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L.
    [Show full text]
  • Introduction to High Contrast Imaging
    Observing Exoplanets with High contrast imaging techniques nulling interferometry & coronagraphy High contrast imaging science and challenges Exoplanets – Exoplanet types: Giants, rocky planets – Contrast ratio, Angular separation: why is it difficult ? – Visible vs. Infrared – Complementarities between direct imaging and indirect techniques – Life finding Disks – Planetary formation – Debris disks Brief introduction to approaches to the high contrast imaging challenge – Why don't normal telescopes work for high contrast imaging ? – Coronagraphy – Nulling interferometry – Ground vs. space Exoplanet discoveries New but very active research topic Most planets are discovered with indirect techniques → limited ability to characterize them, and strong need for direct imaging to learn more about the planets and their environments Exoplanet discoveries Techniques to detect exoplanets around main sequence stars (many of them covered in this course): Radial velocity: measure small shift in star's spectra to compute its speed along line of sight. Astrometry: measure accurate position of star on sky to identify if a planet is pulling the star in a small periodic orbit around the center of mass Transit photometry: if planet passes in front of its star, the star apparent luminosity is reduced Microlensing: planet can bend light, and amplify background starlight through gravitational lensing Direct imaging (with telescope or interferometer): capture high contrast image of the immediate surrounding of a star Habitable planets Potentially habitable planet : – Planet mass sufficiently large to retain atmosphere, but sufficiently low to avoid becoming gaseous giant – Planet distance to star allows surface temperature suitable for liquid water (habitable zone) Habitable zone = zone within which Earth-like planet could harbor life Location of habitable zone is function of star luminosity L.
    [Show full text]
  • Florian Rodler (ESO) Introduction
    Exoplanets Florian Rodler (ESO) Introduction The first exoplanet was discovered in 1995. Florian Rodler - ESO La Silla Observing School Introduction The first exoplanet was discovered in 1995. WRONG ✗ Florian Rodler - ESO La Silla Observing School Early beginnings First alleged exoplanets were reported in the 1940s ... (Strand, 1944, AJ, 51, 12) ✗ Florian Rodler - ESO La Silla Observing School Early beginnings The observational concepts were laid out that ~40 years later led to exoplanet discoveries ... (Struwe, 1952, Obs, 72, 199) Florian Rodler - ESO La Silla Observing School Early beginnings Early claims of exoplanet discoveries (with astrometry): (van de Kamp, 1982, Vistas in Ast., 26, 141) ✗ Florian Rodler - ESO La Silla Observing School Exoplanets found, but not claimed 1988: γ Cep b Campbell, Walker &Yang (ApJ 331, 902) Radial velocities ⇒ no firm discovery claim “Probable third-body variation of 25 m s-1 amplitude, 2.7 yr period” ⇒ in 2003 confirmed by Hatzes et al. (ApJ 599, 1383) ✓ 1989: HD114762b Latham et al. (Nature 339, 38) Radial velocities ⇒ no firm discovery claim “The unseen companion of HD114762 - A probable brown dwarf” ... P = 84 d, m ≥ 11 MJupiter ✓ Florian Rodler - ESO La Silla Observing School Planets around Pulsars 1991: PSR 1829-10 Lyne (Nature 352, 537) Pulsar Timing: Radio pulses arrive earlier and later at Earth time Problem: P = ½ yr ⇒ Error in the correction of the eccentricity of the Earth’s movement. ✗ Florian Rodler - ESO La Silla Observing School Planets around Pulsars 1992: PSR 1257+12 Wolszczan & Frail (Nature
    [Show full text]