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Spectroscopic Survey of Solar Twins

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The planet – stellar chemical composition connection Jorge Meléndez Departamento de Astronomia IAG - Univ. São Paulo Ivan Ramirez (Austin), J. Bean (Chicago), P. Baumann, M. Bergemann, K. Lind (MPA), B. Gustafsson (Uppsala), D. Yong, A. Karakas, M. Asplund, A. Alves Brito (Stromlo), T. Monroe, M. Tucci Maia (IAG/USP), M. Castro, J.D. do Nascimento (UFRN) Outline • Metallicity – giant planet connection • Lithium: is there a link to planets ? • Signatures of terrestrial planets • Signatures of giant planets • Solar twin planet survey with HARPS at ESO Sunset in Paracas, Peru (c) www.flickr.com/photos/rodrigocampos/ Metallicity – giant planet connection Metallicity – giant planet connection Stars with Comparison giant planets sample Metallicity – giant planet connection 1040 FGK-type stars metallicity Lithium: is there a planet connection? Orgueil meteorite CI carbonaceous chondrite • Li is severely depleted in the Sun • The Sun is a planet host ... • Is the solar Li abundance typical of other Suns ? 0 1 2 3 4 5 Meléndez et al. 2010 Ap&SS 328, 193 Lithium: is there a planet connection? Is the Sun peculiar in Li? Sun vs. Stars with Planets (SWP) and without Planets ʘ Gonzalez et al (2010): Sun has a Li abundance 0.7 dex lower than 50 comparison stars Lithium: is there a planet connection? Open cluster with solar age (~ 4 Gyr) and slightly higher [Fe/H] = +0.03 Solar twins in M67 (Pasquini et al. 2008) Randich et al. 2006, Pace et al. 2008) Sun seems normal in Li with respect to solar twins in M67. Using solar twins to learn more on the solar Li abundance and Li-depletion High resolution (R=65,000) high S/N (200-450) spectra McDonald 2.7m Magellan 6.5m - Meléndez et al. 2010, Ap&SS, 328, 193 - Baumann, Ramirez, Melendez, Asplund & Lind 2010, A&A, 519, A87 Lithium in solar twins (Meléndez et al. 2010 Ap&SS 328, 193) The solar Li is “normal” for a 1-solar- mass of solar metallicity at 4.6 Gyr Yonsei-Yale isochrones Solar twins in Coma Benerices open Hyades NGC762 cluster and field stars M67 The solar Li is normal for a 1-solar-mass star at 4.6 Gyr (Meléndez et al. 2010 Ap&SS 328, 193) Non- standard solar models roughly fit data Montalban & Schatzmann: mixing by internal waves Xiong & Deng: Convective overshooting + gravitational settling Do Nascimento et al: Difussion + grav settling + rotation-induced mixing (Meléndez et al. 2010 Ap&SS 328, 193) Conclusion: the Sun has a normal Li abundance (for a solar-metallicity solar- age one-solar-mass star) What about lithium in stars with giant planets ? Planet hosts Comparison Planet-host stars around solar Teff seem depleted in Li You cannot compare apples and oranges ... comparer des pommes avec des oranges comparer des pommes et des poires comparar peras con manzanas You cannot add pears and apples … No puedes sumar peras con manzanas Comparing Luminosity apples & apples Li depletion is not enhanced in planet hosts ! Comparing apples & apples (only stars with similar stellar parameters within 2-sigma) Planet hosts Comparison Baumann, Ramírez, Meléndez, & Asplund 2010, A&A, 519, A87 Li depletion is not enhanced in planet hosts ! Apples & oranges Israelian et al. 2009, Nature Planet hosts Comparison Apples & apples Baumann, Ramírez, Meléndez, & Asplund 2010, A&A, 519, A87 Conclusion on lithium: there is no difference in Li abundance between stars with and without planets Li-7 : no planet connection The Sun has a normal Li abundance, but what about other chemical elements ? Are the solar abundances typical of other Suns ? Magellan ultra high Observations of the solar twin 18 Sco precision study of solar twins - Magellan 6.5m Clay Telescope & Mike spectrometer - R = 65,000 - S/N = 450 per pixel - coverage 340 – 1000 nm - Solar spectrum: Vesta - 3 nights of observations BLUE frame RED frame Example of Magellan spectra (total spectral coverage 3400 A -1um) Small part (597-603nm) of solar twin & Sun’s spectra Meléndez et al. 2009, ApJ, 704, L66 Δ abundance: Sun - <twins> vs. atomic number Z Sun typical : Δ = 0 Sun weird : Δ ≠ 0 Our solar system is not host by a typical ‘Sun’ Meléndez et al. 2009 Sun’s anomalies are strongly correlated to dust condensation temperature of the elements! Correlation is highly significant ~ 0.08 dex ~ 20% probability ~10-9 to happen by chance It’s most likely to win Dust condensation temperature (K) the lottery Meléndez et al. 2009 Condensation in the solar nebula Mercury Venus Condensation The late accreted gas in the convection zone Meléndez et 2009 al. Meléndez was deficient in refractories The missing refractories were used to form dust, planetesimals & terrestrial planets Relation with terrestrial planet formation: Tcond trend in meteorites Alexander et al. (2001) The abundance pattern seen in meteorites is a mirror-image of the Sun’s chemical composition Relation with terrestrial planet formation: Amount of dust removed from the Sun is enough to form terrestrial planets How much dust-cleansed gas is required to affect the Sun in this way? Assume gas accretion until solar convection zone reached ~ present size (~0.02 Msun): Refractories depleted in the 28 Sun: ~2*10 g ≈ 4 M Refractories locked-up in terrestrial planets: 27 ~8*10 g ≈ 1.3 M SUN Earth-like material SUN Meteorite-like material SUN Earth-like material Meteorite-like material Are there other solutions besides rocky planets? Could it be a problem in the abundance analysis ? Is the effect confirmed by other samples ? Can you really get this unprecedented precision ? Any problems with the asteroids used ? Could it be just pollution by a supernova or AGB ? Perhaps it is just galactic chemical evolution ? What about random line-of-sight effects ? Could it be an age effect? No matter what, I don’t believe it Results are almost independent of adopted model atmospheres As the stars are solar twins, the results do not depend much on the adopted models. Effect of using different sets of models is only ~0,001 dex Meléndez et al. 2012, A&A, 543, A29 Yes, the abundance trend is real The abundance signature is also seen in other samples and using different instruments and different asteroids Our Sun is indeed anomalous in its chemical makeup Meléndez et al. 2012, A&A, 543, A29 High precision (0,005 dex) is possible ! Analysis of solar spectra using two different asteroids shows that it is possible to achieve a precision of about 0,005 dex ! Meléndez et al. 2012, A&A, 543, A29 Asteroids are suitable for high precision high resolution spectroscopy Comparison of asteroids of different spectral types shows no meaningful trend with condensation temperature Juno Ceres Chapman, Morrison & Zellner (1975) Meléndez et al. 2012, A&A, 543, A29 There is no line-of-sight (inclination) effect There are no changes in the abundances obtained at different latitudes in the Sun for both volatile (to within 0.005 dex) and refractory (to within 0.002 dex) elements. Pollution by AGB stars, supernova type II, supernova type Ia, or hypernova, are not responsible for the abundance signature Meléndez et al. 2012, A&A, 543, A29 Also, the abundance signature cannot be explained by age by galactic chemical evolution effects The most likely explanation for the abundance signature seems to be the formation of terrestrial planets HIP 56948 : the most ScienceNews, 30/8/2012, Star's missing elements could signal lurking likely candidate for small planets: solar chemistry suggests best places to hunt. hosting other Earths ? Meléndez et al. 2012 Rádio USP - Revista FAPESP, 6/7/2012, Um outro Sol. Revista FAPESP, 6/2012, Um segundo sol. Veja, 4/5/2012, Astrônomo da USP revela estrela 'gêmea' do Sol. Discovery News, 26/4/2012, Sun's Object: the star HIP 56948 twin discovered ? the perfect seti Size: same as the Sun target ? Temperature: same as the Sun Composition: same as the Sun New Scientist, 20/4/2012, Astrophile: Planets: same as the Sun? an alien sunrise just like Earth's. Meléndez et al. 2012, A&A, 543, A29 HIP 56948: best solar twin Comparison of HIP56948 (red circles) and the Sun (solid line) HIRES spectra R ~ 95,000, S/N=600 Meléndez et al. 2012, A&A, 543, A29 HIP 56948 is very similar to the Sun in physical parameters and chemical abundances Meléndez et al. 2012, A&A, 543, A29 Abundance pattern of HIP 56948 is compatible with 1,5 Earth masses of Earth-like material (using Earth’s composition from Chambers 2010) Meléndez et al. 2012, A&A, 543, A29 Planet search for HIP 56948 No giant planets in the terrestrial planet region around HIP 56948 ! Looks promising for hosting Earth-like planets in the habitable zone Meléndez et al. 2012, A&A, 543, A29 What about the effect of giant planet formation? 16 Cyg: pair of solar analogs 16 Cyg A : no planets 16 Cyg B : giant planet 16 Cyg B (planet-host) is 0,04 dex more metal-poor in all elements (photospheric abundances)! Was the missing material used to form the giant planet around the solar analog 16 Cyg B ? Large Programme: 88 nights at La Silla 3.6m telescope + HARPS spectrograph Brasil no ESO: primeiros resultados 3af, 14:30 (Salão Pentágono) Planets around solar twins PI: Jorge Meléndez (IAG/USP) Collaborators: T. Monroe (IAG/USP) Australia: Alan Alves Brito, M. Asplund, L. Casagrande USA: I. Ramírez, J. Bean Germany: P. Baumann, S. Dreizler, K. Lind © Ana M. Molina at La Silla Our Large Programme explores the planet – star connection using precise chemical abundances (0,01 dex) and precise radial velocities (1m/s) obtained with HARPS @ 3,6m telescope. 88 nights from Oct 2011 – Oct 2015 Large Programme: 88 nights at La Silla 3.6m telescope + HARPS spectrograph Current Status - Whole sample observed with VLT and Magellan for high precision (0,01 dex) abundance analysis - About 70 solar twins being observed for planets using HARPS at 1m/s precision - Visitor observing runs in Oct 2011, Feb 2012, April 2012, August 2012, January 2013, …, 2015 © Jorge Meléndez at La Silla First results from our HARPS planet search around solar twins: Jupiter candidate Pesquisa sobre procura de planetas com o HARPS é destaque na mídia nacional O estudo se viabilizou graças ao acesso recém-obtido pelo Brasil às instalações do ESO (Observatório Europeu do Sul).
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    2012 Annual Report FY2012 432 Observing Astronomers 407 Keck Science Investigations 328 Refereed Articles 108 Full-time Employees Fiscal Year begins October 1 Federal Identification Number: 95-3972799 2012 Annual Report HEADQUARTERS LOCATION: Kamuela, Hawai’i, USA MANAGEMENT: California Association for Table of Research in Astronomy Contents 8-9 PARTNER INSTITUTIONS: California Institute of Technology (CIT/Caltech), University of California (UC), Director’s National Aeronautics and Space Administration (NASA) Report OBSERVATORY DIRECTOR: Taft E. Armandroff DEPUTY DIRECTOR: Hilton A. Lewis Observatory Groundbreaking: 1985 First light Keck I telescope: 1992 First light Keck II telescope: 1996 vision A world in which all humankind is inspired and united by the pursuit of knowledge of the infinite variety and richness of the Universe. mission To advance the frontiers of astronomy and share our discoveries, inspiring the imagination of all. Cover Image: Color composite image of the Antennae Galaxy obtained by MOSFIRE in May 2012 in which the two infrared bands, J and K, are color- coded blue and red to give an impression of what infrared eyes would see. The reddish blobs are actually large star-forming clusters, which are hidden from sight in normal visible light images. Previous Spread: Keck II gleams in the sun, while the operations crew inside expertly prepares for another night of science. 11 13-17 19-27 28-33 35-37 39-47 Cosmic Astro Science Funding Education Science Visionaries Moxie Highlights & Outreach Bibliography EDITOR/WRITER Debbie Goodwin ADDITIONAL WRITERS Taft Armandroff Robert Goodrich Steve Jefferson Thatcher Moats CONTRIBUTORS AND SUPPort Joan Campbell Peggi Kamisato Hilton Lewis Jeff Mader Margarita Scheffel Gerald Smith Bob Steele GRAPHIC DESIGN Waimea Instant Printing PRINTING Service Printers Hawaii, Inc.
  • Solar Twins and Solar Analogues in Galactic Surveys

    Solar Twins and Solar Analogues in Galactic Surveys

    SOLAR TWINS AND SOLAR ANALOGUES IN GALACTIC SURVEYS Juliet Clare Datson TURUN YLIOPISTON JULKAISUJA – ANNALES UNIVERSITATIS TURKUENSIS Sarja - ser. AI osa - tom. 497 | Astronomica - Chemica - Physica - Mathematica | Turku 2014 University of Turku Faculty of Mathematics and Natural Sciences Department of Physics and Astronomy Supervised by Dr. Chris Flynn Dr. Laura Portinari Department of Physics and Astronomy Department of Physics and Astronomy University of Turku University of Turku Finland Finland Reviewed by Dr. Andreas J. Korn Prof. Dr. Jorge Meléndez Department of Physics and Astronomy Departamento de Astronomia Uppsala University Universidade de São Paulo Sweden Brazil Opponent Prof. Dr. Sofia Feltzing Lund Observatory Lund University Sweden The originality of this thesis has been checked in accordance with the University of Turku quality assurance system using the Turnitin OriginalityCheck service. ISBN 978-951-29-5913-6 (PRINT) ISBN 978-951-29-5914-3 (PDF) ISSN 0082-7002 Painosalama Oy - Turku, Finland 2014 Acknowledgements Many warm and heartfelt thanks are due to so many people that made this possible, that I am sure I will forget some in this short, or not so short, summary. To those I say thank you and I am sorry for not specifically men- tioning you, there are just too many to remember them all. Additionally there are so many people I would like to mention, that I cannot list you all separately, you know who you are. First I would like to thank Chris Flynn, who brought me to Finland. I sent an email enquiring about possible PhD positions to people in Helsinki and until now I do not know how that ended up in Chris’ hands, but it did and he invited me to come to Turku instead, where he became one of my supervisors.
  • Searching for New Solar Twins: the Inti Survey for the Northern Sky

    Searching for New Solar Twins: the Inti Survey for the Northern Sky

    MNRAS 000,1–15 (2021) Preprint 8 April 2021 Compiled using MNRAS LATEX style file v3.0 Searching for new solar twins: The Inti survey for the Northern Sky Jhon Yana Galarza1¢, Ricardo López-Valdivia2, Diego Lorenzo-Oliveira1, Henrique Reggiani3, Jorge Meléndez1, Daniel Gamarra-Sánchez4, Matias Flores5,6,7, Jerry Portal-Rivera4, Paula Miquelarena5,6,7, Geisa Ponte1,8, Kevin C. Schlaufman3, and Teófilo Vargas Auccalla4 1Universidade de São Paulo, Departamento de Astronomia do IAG/USP, Rua do Matão 1226 Cidade Universitária, 05508-900 São Paulo, SP, Brazil 2The University of Texas at Austin, Department of Astronomy, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 3 Department of Physics and Astronomy, Johns Hopkins University, 3400 N Charles St., Baltimore, MD 21218 4 Seminario Permanente de Astronomía y Ciencias Espaciales, Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Avenida Venezuela s/n, Lima 15081, Perú 5 Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina 6Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina 7Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE), España Sur 1512, CC 49, 5400 San Juan, Argentina 8CRAAM, Mackenzie Presbyterian University, Rua da Consolação, 896, São Paulo, Brazil Accepted 2021 April 05. Received 2021 March 23; in original form 2020 December 17 ABSTRACT Solar twins are key in different areas of astrophysics, however only just over a hundred were identified and well-studied in the last two decades. In this work, we take advantage of the very precise Gaia (DR2/EDR3), Tycho and 2MASS photometric systems to create the Inti survey of new solar twins in the Northern Hemisphere.