Gaia Search for Stellar Companions of TESS Objects of Interest
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Enabling Science with Gaia Observations of Naked-Eye Stars
Enabling science with Gaia observations of naked-eye stars J. Sahlmanna,b, J. Mart´ın-Fleitasb,c, A. Morab,c, A. Abreub,d, C. M. Crowleyb,e, E. Jolietb,f aEuropean Space Agency, STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA; bEuropean Space Agency, ESAC, P.O. Box 78, Villanueva de la Canada,˜ 28691 Madrid, Spain; cAurora Technology, Crown Business Centre, Heereweg 345, 2161 CA Lisse, The Netherlands; dElecnor Deimos Space, Ronda de Poniente 19, Ed. Fiteni VI, 28760 Tres Cantos, Madrid, Spain; eHE Space Operations BV, Huygensstraat 44, 2201 DK Noordwijk, The Netherlands; fCalifornia Institute of Technology, Pasadena, CA, 91125, USA ABSTRACT ESA’s Gaia space astrometry mission is performing an all-sky survey of stellar objects. At the beginning of the nominal mission in July 2014, an operation scheme was adopted that enabled Gaia to routinely acquire observations of all stars brighter than the original limit of G∼6, i.e. the naked-eye stars. Here, we describe the current status and extent of those observations and their on-ground processing. We present an overview of the data products generated for G<6 stars and the potential scientific applications. Finally, we discuss how the Gaia survey could be enhanced by further exploiting the techniques we developed. Keywords: Gaia, Astrometry, Proper motion, Parallax, Bright Stars, Extrasolar planets, CCD 1. INTRODUCTION There are about 6000 stars that can be observed with the unaided human eye. Greek astronomer Hipparchus used these stars to define the magnitude system still in use today, in which the faintest stars had an apparent visual magnitude of 6. -
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. -
Precise Radial Velocities of Giant Stars
A&A 555, A87 (2013) Astronomy DOI: 10.1051/0004-6361/201321714 & c ESO 2013 Astrophysics Precise radial velocities of giant stars V. A brown dwarf and a planet orbiting the K giant stars τ Geminorum and 91 Aquarii, David S. Mitchell1,2,SabineReffert1, Trifon Trifonov1, Andreas Quirrenbach1, and Debra A. Fischer3 1 Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany 2 Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA e-mail: [email protected] 3 Department of Astronomy, Yale University, New Haven, CT 06511, USA Received 16 April 2013 / Accepted 22 May 2013 ABSTRACT Aims. We aim to detect and characterize substellar companions to K giant stars to further our knowledge of planet formation and stellar evolution of intermediate-mass stars. Methods. For more than a decade we have used Doppler spectroscopy to acquire high-precision radial velocity measurements of K giant stars. All data for this survey were taken at Lick Observatory. Our survey includes 373 G and K giants. Radial velocity data showing periodic variations were fitted with Keplerian orbits using a χ2 minimization technique. Results. We report the presence of two substellar companions to the K giant stars τ Gem and 91 Aqr. The brown dwarf orbiting τ Gem has an orbital period of 305.5±0.1 days, a minimum mass of 20.6 MJ, and an eccentricity of 0.031±0.009. The planet orbiting 91 Aqr has an orbital period of 181.4 ± 0.1 days, a minimum mass of 3.2 MJ, and an eccentricity of 0.027 ± 0.026. -
Mètodes De Detecció I Anàlisi D'exoplanetes
MÈTODES DE DETECCIÓ I ANÀLISI D’EXOPLANETES Rubén Soussé Villa 2n de Batxillerat Tutora: Dolors Romero IES XXV Olimpíada 13/1/2011 Mètodes de detecció i anàlisi d’exoplanetes . Índex - Introducció ............................................................................................. 5 [ Marc Teòric ] 1. L’Univers ............................................................................................... 6 1.1 Les estrelles .................................................................................. 6 1.1.1 Vida de les estrelles .............................................................. 7 1.1.2 Classes espectrals .................................................................9 1.1.3 Magnitud ........................................................................... 9 1.2 Sistemes planetaris: El Sistema Solar .............................................. 10 1.2.1 Formació ......................................................................... 11 1.2.2 Planetes .......................................................................... 13 2. Planetes extrasolars ............................................................................ 19 2.1 Denominació .............................................................................. 19 2.2 Història dels exoplanetes .............................................................. 20 2.3 Mètodes per detectar-los i saber-ne les característiques ..................... 26 2.3.1 Oscil·lació Doppler ........................................................... 27 2.3.2 Trànsits -
Erosion of an Exoplanetary Atmosphere Caused by Stellar Winds J
A&A 630, A52 (2019) https://doi.org/10.1051/0004-6361/201935543 Astronomy & © ESO 2019 Astrophysics Erosion of an exoplanetary atmosphere caused by stellar winds J. M. Rodríguez-Mozos1 and A. Moya2,3 1 University of Granada (UGR), Department of Theoretical Physics and Cosmology, 18071 Granada, Spain 2 School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK e-mail: [email protected]; [email protected] 3 Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark Received 26 March 2019 / Accepted 8 August 2019 ABSTRACT Aims. We present a formalism for a first-order estimation of the magnetosphere radius of exoplanets orbiting stars in the range from 0.08 to 1.3 M . With this radius, we estimate the atmospheric surface that is not protected from stellar winds. We have analyzed this unprotected surface for the most extreme environment for exoplanets: GKM-type and very low-mass stars at the two limits of the habitable zone. The estimated unprotected surface makes it possible to define a likelihood for an exoplanet to retain its atmosphere. This function can be incorporated into the new habitability index SEPHI. Methods. Using different formulations in the literature in addition to stellar and exoplanet physical characteristics, we estimated the stellar magnetic induction, the main characteristics of the stellar wind, and the different star-planet interaction regions (sub- and super- Alfvénic, sub- and supersonic). With this information, we can estimate the radius of the exoplanet magnetopause and thus the exoplanet unprotected surface. -
Erosion of an Exoplanetary Atmosphere Caused by Stellar Winds J
Astronomy & Astrophysics manuscript no. atmosphere_erision ©ESO 2019 August 20, 2019 Erosion of an exoplanetary atmosphere caused by stellar winds J. M. Rodríguez-Mozos1 and A. Moya2; 3 1 University of Granada (UGR). Dept. Theoretical Physics and Cosmology. 18071. Granada. Spain 2 School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK 3 Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark e-mail: [email protected] Received September 15, 1996; accepted March 16, 1997 ABSTRACT Aims. We present a formalism for a first-order estimation of the magnetosphere radius of exoplanets orbiting stars in the range from 0.08 to 1.3 M . With this radius, we estimate the atmospheric surface that is not protected from stellar winds. We have analyzed this unprotected surface for the most extreme environment for exoplanets: GKM-type and very low-mass stars at the two limits of the habitable zone. The estimated unprotected surface makes it possible to define a likelihood for an exoplanet to retain its atmosphere. This function can be incorporated into the new habitability index SEPHI. Methods. Using different formulations in the literature in addition to stellar and exoplanet physical characteristics, we estimated the stellar magnetic induction, the main characteristics of the stellar wind, and the different star-planet interaction regions (sub- and super-Alfvénic, sub- and supersonic). With this information, we can estimate the radius of the exoplanet -
Feasibility of Spectro-Polarimetric Characterization of Exoplanetary Atmospheres with Direct Observing Instruments J
A&A 599, A56 (2017) Astronomy DOI: 10.1051/0004-6361/201628206 & c ESO 2017 Astrophysics Feasibility of spectro-polarimetric characterization of exoplanetary atmospheres with direct observing instruments J. Takahashi1, T. Matsuo2, and Y. Itoh1 1 Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2, Nishigaichi, Sayo, 679-5313 Hyogo, Japan e-mail: [email protected] 2 Department of Earth and Space Science, Graduate School of Science, Osaka University 1–1, Machikaneyama-Cho, Toyonaka, 560-0043 Osaka, Japan Received 28 January 2016 / Accepted 9 November 2016 ABSTRACT Context. Spectro-polarimetry of reflected light from exoplanets is anticipated to be a powerful method for probing atmospheric composition and structure. Aims. We aim to evaluate the feasibility of the search for a spectro-polarimetric feature of water vapor using a high-contrast polari- metric instrument on a 30–40 m-class ground-based telescope. Methods. Three types of errors are considered: (a) errors from the difference between efficiencies for two orthogonally polarized states; (b) errors caused by speckle noises; and (c) errors caused by photon noise from scattered starlight. Using the analytically derived error formulas, we estimate the number of planets for which feasible spectro-polarimetric detection of water vapor is possible. Results. Our calculations show that effective spectro-polarimetric searches for water vapor are possible for 5 to 14 known planets. Spectro-polarimetric characterization of exoplanetary atmospheres is feasible with an extremely large telescope and a direct observing spectro-polarimeter. Key words. planetary systems – techniques: polarimetric – instrumentation: polarimeters 1. Introduction spectra were less clear. Similarly, Stam(2008) pointed out that the degree of polarization at the continuum wavelengths near a Spectro-polarimetric observations of visible or near-infrared re- molecular feature is more sensitive to the altitude of the cloud’s flected light from exoplanets can be a powerful tool for probing top compared with intensity. -
Direct Detection of Exoplanets in the 3–10 Μm Range with E-ELT/METIS
International Journal of Astrobiology 14 (2): 279–289 (2015) doi:10.1017/S1473550414000135 © Cambridge University Press 2014 Direct detection of exoplanets in the 3–10 μm range with E-ELT/METIS Sascha P. Quanz1, Ian Crossfield2, Michael R. Meyer1, Eva Schmalzl3 and Jenny Held4 1Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland e-mail: [email protected] 2Max Planck Institute for Astronomy, Konigstuhl 17, 69117 Heidelberg, Germany 3Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands 4Department of Physics, ETH Zurich, 8093 Zurich, Switzerland Abstract: We quantify the scientific potential for exoplanet imaging with the mid-infrared E-ELT Imager and Spectrograph (METIS) foreseen as one of the instruments of the European Extremely Large Telescope (E-ELT). We focus on two main science cases: (1) the direct detection of known gas giant planets found by radial velocity (RV) searches; and (2) the direct detection of small (1–4R⊕) planets around the nearest stars. Under the assumptions made in our modelling, in particular on the achievable inner working angle and sensitivity, our analyses reveal that within a reasonable amount of observing time METIS is able to image >20 already known, RV-detected planets in at least one filter. Many more suitable planets with dynamically determined masses are expected to be found in the coming years with the continuation of RV-surveys and the results from the GAIA astrometry mission. In addition, by extrapolating the statistics for close-in planets found by Kepler, we expect METIS might detect &10 small planets with equilibrium temperatures between 200 and 500 K around the nearest stars. -
Feasibility of Spectro-Polarimetric Detection of Atmospheric Components of Exoplanets
Feasibility of Spectro-Polarimetric Detection of Atmospheric Components of Exoplanets Jun Takahashi (University of Hyogo) Taro Matsuo (Osaka University) Polarimetry for planets • Reflection makes polarization. Polarization of the reflected light from a planet has information of its atmosphere, clouds and surface. • Polarimetry has been a powerful method to investigate Solar-System objects. For example, polarimetry for Venus (e.g., Lyot 1929) played a key role to identify H2SO4 hazes by determining the size and refractive index of the reflecting particles. • As is for Solar-System planets, polarimetry for exoplanets may be a good diagnostic tool to know … • atmospheric composition • cloud/haze altitude (Stam 2004, 2008) • optical thickness of atmosphere ? (Takahashi+ 2013) • existence of a surface ocean ?? (McCullough 2006) Pol. spectra of planets • Model calculations 668 D. M. Stam et al.: Polarimetry to detect and characterize Jupiter-like extrasolar planets Earth-like planet, Stam(2008) Jupiter-like planet, Stam(2004) ) 0.20 1.0 % P ( a. b. CH3 features 0.8 0.15 F 0.6 H2O clear 0.10 O2 Flux model 1 0.4 0.05 model 2 low cloud model 3 0.2 Degree of polarization Deg. of polarization, P ofpolarization, Deg. high haze 0.00 0.0 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.4 0.5 0.6 0.7 0.8 0.9 1.0 WavelengthWavelength(nm) (µm) Wavelength (µm) Fig. 4. The flux F• andThe degree enhanced of polarization featuresP of are starlight explained reflected by by the three decrease Jupiter-like in EGPs intensity for α = of90 ◦the.Planetarymodelatmosphere1 (solid lines) containsmultiply only molecules, scattered model component 2 (dashed lines) at is the simila absorptionrtomodel1,exceptforatroposphericcloudlayer,andmodel3(dotted wavelengths as compared lines) is similar to modelwith 2, that except at for the a stratospheric continuum haze wavelengths layer. -
Survival of Exomoons Around Exoplanets 2
Survival of exomoons around exoplanets V. Dobos1,2,3, S. Charnoz4,A.Pal´ 2, A. Roque-Bernard4 and Gy. M. Szabo´ 3,5 1 Kapteyn Astronomical Institute, University of Groningen, 9747 AD, Landleven 12, Groningen, The Netherlands 2 Konkoly Thege Mikl´os Astronomical Institute, Research Centre for Astronomy and Earth Sciences, E¨otv¨os Lor´and Research Network (ELKH), 1121, Konkoly Thege Mikl´os ´ut 15-17, Budapest, Hungary 3 MTA-ELTE Exoplanet Research Group, 9700, Szent Imre h. u. 112, Szombathely, Hungary 4 Universit´ede Paris, Institut de Physique du Globe de Paris, CNRS, F-75005 Paris, France 5 ELTE E¨otv¨os Lor´and University, Gothard Astrophysical Observatory, Szombathely, Szent Imre h. u. 112, Hungary E-mail: [email protected] January 2020 Abstract. Despite numerous attempts, no exomoon has firmly been confirmed to date. New missions like CHEOPS aim to characterize previously detected exoplanets, and potentially to discover exomoons. In order to optimize search strategies, we need to determine those planets which are the most likely to host moons. We investigate the tidal evolution of hypothetical moon orbits in systems consisting of a star, one planet and one test moon. We study a few specific cases with ten billion years integration time where the evolution of moon orbits follows one of these three scenarios: (1) “locking”, in which the moon has a stable orbit on a long time scale (& 109 years); (2) “escape scenario” where the moon leaves the planet’s gravitational domain; and (3) “disruption scenario”, in which the moon migrates inwards until it reaches the Roche lobe and becomes disrupted by strong tidal forces. -
HD60532, a Planetary System in a 3: 1 Mean Motion Resonance
Astronomy & Astrophysics manuscript no. hd60532˙vb c ESO 2018 November 1, 2018 Letter to the Editor HD60532, a planetary system in a 3:1 mean motion resonance. J. Laskar1 and A.C.M. Correia1,2 1 ASD, IMCCE, CNRS-UMR8028, Observatoire de Paris, UPMC, 77 avenue Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] 2 Departamento de F´ısica, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal e-mail: [email protected] Received ; accepted To be inserted later ABSTRACT In a recent paper it was reported a planetary system around the star HD 60532, composed by two giant planets in a possible 3:1 mean motion resonance, that should be confirmed within the next decade. Here we show that the analysis of the global dynamics of the system allows to confirm this resonance. The present best fit to data already corresponds to this resonant configuration and the system is stable for at least 5 Gry. The 3:1 resonance is so robust that stability is still possible for a wide variety of orbital parameters around the best fit solution and also if the inclination of the system orbital plane with respect to the plane of the sky is as small as 15◦. Moreover, if the inclination is taken as a free parameter in the adjustment to the observations, we find an inclination ∼ 20◦, which corresponds to Mb = 3.1 MJup and Mc = 7.4 MJup for the planetary companions. Key words. stars: individual: HD 60532 – stars: planetary systems – techniques: radial velocities 1. Introduction 2. Orbital solution for the HD 60532 system In a recent paper (Desort et al. -
Direct Detection of Exoplanets in the 3–10 Μm Range with E-ELT/ METIS
Research Collection Journal Article Direct detection of exoplanets in the 3–10 μm range with E-ELT/ METIS Author(s): Quanz, Sascha Patrick; Crossfield, Ian; Meyer, Michael R.; Schmalzl, Eva; Held, Jenny Publication Date: 2015-04 Permanent Link: https://doi.org/10.3929/ethz-b-000413377 Originally published in: International Journal of Astrobiology 14(2), http://doi.org/10.1017/S1473550414000135 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library International Journal of Astrobiology 14 (2): 279–289 (2015) doi:10.1017/S1473550414000135 © Cambridge University Press 2014 Direct detection of exoplanets in the 3–10 μm range with E-ELT/METIS Sascha P. Quanz1, Ian Crossfield2, Michael R. Meyer1, Eva Schmalzl3 and Jenny Held4 1Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland e-mail: [email protected] 2Max Planck Institute for Astronomy, Konigstuhl 17, 69117 Heidelberg, Germany 3Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands 4Department of Physics, ETH Zurich, 8093 Zurich, Switzerland Abstract: We quantify the scientific potential for exoplanet imaging with the mid-infrared E-ELT Imager and Spectrograph (METIS) foreseen as one of the instruments of the European Extremely Large Telescope (E-ELT). We focus on two main science cases: (1) the direct detection of known gas giant planets found by radial velocity (RV) searches; and (2) the direct detection of small (1–4R⊕) planets around the nearest stars. Under the assumptions made in our modelling, in particular on the achievable inner working angle and sensitivity, our analyses reveal that within a reasonable amount of observing time METIS is able to image >20 already known, RV-detected planets in at least one filter.