The Search for Habitable Environments and Life in the Universe
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The Discovery of Exoplanets
L'Univers, S´eminairePoincar´eXX (2015) 113 { 137 S´eminairePoincar´e New Worlds Ahead: The Discovery of Exoplanets Arnaud Cassan Universit´ePierre et Marie Curie Institut d'Astrophysique de Paris 98bis boulevard Arago 75014 Paris, France Abstract. Exoplanets are planets orbiting stars other than the Sun. In 1995, the discovery of the first exoplanet orbiting a solar-type star paved the way to an exoplanet detection rush, which revealed an astonishing diversity of possible worlds. These detections led us to completely renew planet formation and evolu- tion theories. Several detection techniques have revealed a wealth of surprising properties characterizing exoplanets that are not found in our own planetary system. After two decades of exoplanet search, these new worlds are found to be ubiquitous throughout the Milky Way. A positive sign that life has developed elsewhere than on Earth? 1 The Solar system paradigm: the end of certainties Looking at the Solar system, striking facts appear clearly: all seven planets orbit in the same plane (the ecliptic), all have almost circular orbits, the Sun rotation is perpendicular to this plane, and the direction of the Sun rotation is the same as the planets revolution around the Sun. These observations gave birth to the Solar nebula theory, which was proposed by Kant and Laplace more that two hundred years ago, but, although correct, it has been for decades the subject of many debates. In this theory, the Solar system was formed by the collapse of an approximately spheric giant interstellar cloud of gas and dust, which eventually flattened in the plane perpendicular to its initial rotation axis. -
Modeling Super-Earth Atmospheres in Preparation for Upcoming Extremely Large Telescopes
Modeling Super-Earth Atmospheres In Preparation for Upcoming Extremely Large Telescopes Maggie Thompson1 Jonathan Fortney1, Andy Skemer1, Tyler Robinson2, Theodora Karalidi1, Steph Sallum1 1University of California, Santa Cruz, CA; 2Northern Arizona University, Flagstaff, AZ ExoPAG 19 January 6, 2019 Seattle, Washington Image Credit: NASA Ames/JPL-Caltech/T. Pyle Roadmap Research Goals & Current Atmosphere Modeling Selecting Super-Earths for State of Super-Earth Tool (Past & Present) Follow-Up Observations Detection Preliminary Assessment of Future Observatories for Conclusions & Upcoming Instruments’ Super-Earths Future Work Capabilities for Super-Earths M. Thompson — ExoPAG 19 01/06/19 Research Goals • Extend previous modeling tool to simulate super-Earth planet atmospheres around M, K and G stars • Apply modified code to explore the parameter space of actual and synthetic super-Earths to select most suitable set of confirmed exoplanets for follow-up observations with JWST and next-generation ground-based telescopes • Inform the design of advanced instruments such as the Planetary Systems Imager (PSI), a proposed second-generation instrument for TMT/GMT M. Thompson — ExoPAG 19 01/06/19 Current State of Super-Earth Detections (1) Neptune Mass Range of Interest Earth Data from NASA Exoplanet Archive M. Thompson — ExoPAG 19 01/06/19 Current State of Super-Earth Detections (2) A Approximate Habitable Zone Host Star Spectral Type F G K M Data from NASA Exoplanet Archive M. Thompson — ExoPAG 19 01/06/19 Atmosphere Modeling Tool Evolution of Atmosphere Model • Solar System Planets & Moons ~ 1980’s (e.g., McKay et al. 1989) • Brown Dwarfs ~ 2000’s (e.g., Burrows et al. 2001) • Hot Jupiters & Other Giant Exoplanets ~ 2000’s (e.g., Fortney et al. -
History of Astrometry
5 Gaia web site: http://sci.esa.int/Gaia site: web Gaia 6 June 2009 June are emerging about the nature of our Galaxy. Galaxy. our of nature the about emerging are More detailed information can be found on the the on found be can information detailed More technologies developed by creative engineers. creative by developed technologies scientists all over the world, and important conclusions conclusions important and world, the over all scientists of the Universe combined with the most cutting-edge cutting-edge most the with combined Universe the of The results from Hipparcos are being analysed by by analysed being are Hipparcos from results The expression of a widespread curiosity about the nature nature the about curiosity widespread a of expression 118218 stars to a precision of around 1 milliarcsecond. milliarcsecond. 1 around of precision a to stars 118218 trying to answer for many centuries. It is the the is It centuries. many for answer to trying created with the positions, distances and motions of of motions and distances positions, the with created will bring light to questions that astronomers have been been have astronomers that questions to light bring will accuracies obtained from the ground. A catalogue was was catalogue A ground. the from obtained accuracies Gaia represents the dream of many generations as it it as generations many of dream the represents Gaia achieving an improvement of about 100 compared to to compared 100 about of improvement an achieving orbit, the Hipparcos satellite observed the whole sky, sky, whole the observed satellite Hipparcos the orbit, ear Y of them in the solar neighbourhood. -
100 Closest Stars Designation R.A
100 closest stars Designation R.A. Dec. Mag. Common Name 1 Gliese+Jahreis 551 14h30m –62°40’ 11.09 Proxima Centauri Gliese+Jahreis 559 14h40m –60°50’ 0.01, 1.34 Alpha Centauri A,B 2 Gliese+Jahreis 699 17h58m 4°42’ 9.53 Barnard’s Star 3 Gliese+Jahreis 406 10h56m 7°01’ 13.44 Wolf 359 4 Gliese+Jahreis 411 11h03m 35°58’ 7.47 Lalande 21185 5 Gliese+Jahreis 244 6h45m –16°49’ -1.43, 8.44 Sirius A,B 6 Gliese+Jahreis 65 1h39m –17°57’ 12.54, 12.99 BL Ceti, UV Ceti 7 Gliese+Jahreis 729 18h50m –23°50’ 10.43 Ross 154 8 Gliese+Jahreis 905 23h45m 44°11’ 12.29 Ross 248 9 Gliese+Jahreis 144 3h33m –9°28’ 3.73 Epsilon Eridani 10 Gliese+Jahreis 887 23h06m –35°51’ 7.34 Lacaille 9352 11 Gliese+Jahreis 447 11h48m 0°48’ 11.13 Ross 128 12 Gliese+Jahreis 866 22h39m –15°18’ 13.33, 13.27, 14.03 EZ Aquarii A,B,C 13 Gliese+Jahreis 280 7h39m 5°14’ 10.7 Procyon A,B 14 Gliese+Jahreis 820 21h07m 38°45’ 5.21, 6.03 61 Cygni A,B 15 Gliese+Jahreis 725 18h43m 59°38’ 8.90, 9.69 16 Gliese+Jahreis 15 0h18m 44°01’ 8.08, 11.06 GX Andromedae, GQ Andromedae 17 Gliese+Jahreis 845 22h03m –56°47’ 4.69 Epsilon Indi A,B,C 18 Gliese+Jahreis 1111 8h30m 26°47’ 14.78 DX Cancri 19 Gliese+Jahreis 71 1h44m –15°56’ 3.49 Tau Ceti 20 Gliese+Jahreis 1061 3h36m –44°31’ 13.09 21 Gliese+Jahreis 54.1 1h13m –17°00’ 12.02 YZ Ceti 22 Gliese+Jahreis 273 7h27m 5°14’ 9.86 Luyten’s Star 23 SO 0253+1652 2h53m 16°53’ 15.14 24 SCR 1845-6357 18h45m –63°58’ 17.40J 25 Gliese+Jahreis 191 5h12m –45°01’ 8.84 Kapteyn’s Star 26 Gliese+Jahreis 825 21h17m –38°52’ 6.67 AX Microscopii 27 Gliese+Jahreis 860 22h28m 57°42’ 9.79, -
A Joint ESA-CONSTELLATION Workshop on the Formation of Brown Dwarfs
-ESA- Space Science Faculty Courtesy NASA/JPL-Caltech CONSTELLATION is a European Commission Sixth Framework Marie Curie Research Training Network (contract number MRTN-CT-2006-035890) A joint ESA-CONSTELLATION workshop on the formation of brown dwarfs Contact info: [email protected]! www.rssd.esa.int/BD2009 Gemini Observatory/AURA WORKSHOP Recipes for making brownies: theory vs. observations Scientific Rationale: The origin of Brown Dwarfs (BDs) is an important component of the theory of star formation. Recent ground based and satellite observations are revealing an increasing number of BDs; however, their origin remains somewhat mysterious as their mass is 2 orders of magnitude below the average Jeans mass in star-forming clouds. Explaining why they are so common thus requires detailed understanding of the fragmentation processes during star formation, as well as exploring other formation scenarios. This workshop will focus on recent theoretical and observational progresses in the field of BD formation as well as explore current and future perspectives. Our purpose is to bring together the leading experts working in this field, foster new collabora- tions and, in particular, promote extended interactions among young PhD/post-doc researchers. SOC: L. Spezzi (chair, ESTEC) B. Mer´ın(ESAC) D. Stamatellos (University of Cardiff) V. Konyves (CEA/Saclay,SAp) C. Alves de Oliveira (LAOG, Grenoble) LOC: L. Spezzi (co-chair) J. Walcher (co-chair) G. Beccari Program: 9 September 2009 08:30 - 10:00 Registration + Coffee 10:00 - 10:15 Opening 10:15 - 11:00 I. Bonnell, BD formation, an introductory review Session 1: Observations of BDs Chairman: E. Mouraux 11:00 - 11:30 K. -
Lecture 3 - Minimum Mass Model of Solar Nebula
Lecture 3 - Minimum mass model of solar nebula o Topics to be covered: o Composition and condensation o Surface density profile o Minimum mass of solar nebula PY4A01 Solar System Science Minimum Mass Solar Nebula (MMSN) o MMSN is not a nebula, but a protoplanetary disc. Protoplanetary disk Nebula o Gives minimum mass of solid material to build the 8 planets. PY4A01 Solar System Science Minimum mass of the solar nebula o Can make approximation of minimum amount of solar nebula material that must have been present to form planets. Know: 1. Current masses, composition, location and radii of the planets. 2. Cosmic elemental abundances. 3. Condensation temperatures of material. o Given % of material that condenses, can calculate minimum mass of original nebula from which the planets formed. • Figure from Page 115 of “Physics & Chemistry of the Solar System” by Lewis o Steps 1-8: metals & rock, steps 9-13: ices PY4A01 Solar System Science Nebula composition o Assume solar/cosmic abundances: Representative Main nebular Fraction of elements Low-T material nebular mass H, He Gas 98.4 % H2, He C, N, O Volatiles (ices) 1.2 % H2O, CH4, NH3 Si, Mg, Fe Refractories 0.3 % (metals, silicates) PY4A01 Solar System Science Minimum mass for terrestrial planets o Mercury:~5.43 g cm-3 => complete condensation of Fe (~0.285% Mnebula). 0.285% Mnebula = 100 % Mmercury => Mnebula = (100/ 0.285) Mmercury = 350 Mmercury o Venus: ~5.24 g cm-3 => condensation from Fe and silicates (~0.37% Mnebula). =>(100% / 0.37% ) Mvenus = 270 Mvenus o Earth/Mars: 0.43% of material condensed at cooler temperatures. -
Exoplanet Exploration Program Updates
Exoplanet Exploration Program Updates Dr. Gary H. Blackwood, Program Manager Dr. Karl R. Stapelfeldt, Program Chief Scientist Jet Propulsion Laboratory California Institute of Technology January 7, 2018 ExoPAG 17, National Harbor, Maryland © 2018 All rights reserved Artist concept of Kepler-16b Kepler / K2 Program Progress vs 2010 Decadal Priorities Program Science Updates NASA Exoplanet Exploration Program Astrophysics Division, NASA Science Mission Directorate NASA's search for habitable planets and life beyond our solar system Program purpose described in 2014 NASA Science Plan 1. Discover planets around other stars 2. Characterize their properties 3. Identify candidates that could harbor life ExEP serves the science community and NASA by implementing NASA’s space science vision for exoplanets https://exoplanets.nasa.gov WFIRST JWST2 PLATO Missions TESS Kepler LUVOIR5 CHEOPS 4 Spitzer Gaia Hubble1 Starshade HabEx5 CoRoT3 Rendezvous5 OST5 NASA Non-NASA Missions Missions W. M. Keck Observatory Large Binocular 1 NASA/ESA Partnership Telescope Interferometer NN-EXPLORE 2 NASA/ESA/CSA Partnership 3 CNES/ESA Ground Telescopes with NASA participation 5 4 ESA/Swiss Space Office 2020 Decadal Survey Studies NASA Exoplanet Exploration Program Space Missions and Mission Studies Communications Kepler & Probe-Scale Studies K2 Starshade Coronagraph Supporting Research & Technology Key NASA Exoplanet Science Institute Sustaining Occulting Technology Development Research Masks Deformable Mirrors NN-EXPLORE Keck Single Archives, Tools, Sagan Fellowships, Aperture Professional Engagement Imaging & RV High-Contrast Imaging Deployable Starshades Large Binocular Telescope Interferometer https://exoplanets.nasa.gov 4 NASA Exoplanet Exploration Program Astrophysics Division, Science Mission Directorate Program Office (JPL) PM- Dr. G. Blackwood DPM- K. Short Chief Scientist – Dr. -
Astrophysical Artefact in the Astrometric Detection of Exoplanets ?
Astrophysical artefact in the astrometric detection of exoplanets ? Jean Schneider LUTh – Paris Observatory Work in progress ● Dynamical and brightness astrometry ● Astrophysical sources of excess brightness – Simulations – Observations ● Conclusion 12 Oct 2011 1 Context Ultimate goal: the precise physical characterization of Earth-mass planets in the Habitable Zone (~ 1 AU) by direct spectro- polarimetric imaging It will also require a good knowledge of their mass. Two approaches (also used to find Earth-mass planets): – Radial Velocity measurements – Astrometry 12 Oct 2011 2 Context Radial Velocity and Astrometric mass measurements have both their limitations . Here we investigate a possible artefact of the astrometric approach for the Earth-mass regime at 1 AU. ==> not applicable to Gaia or PRIMA/ESPRI Very simple idea: can a blob in a disc mimic the astrometric signal of an Earth-mass planet at 1 AU? 12 Oct 2011 3 Dynamical and brightness astrometry Baryc. M M * C B I Ph I I << I 1 2 2 1 Photoc. a M a = C ● Dynamical astrometry B M* D I I M ● 2 a 2 C a Brightness (photometric) astrometry Ph= − B= − I1 D I1 M* D Question: can ph be > B ? 12 Oct 2011 4 Dynamical and brightness astrometry Baryc. M M * C B I Ph I I << I 1 2 2 1 Photoc. MC a −6 a ● = B ~ 3 x 10 for a 1 Earth-mass planet M* D D I a I a = 2 − ~ 2 -6 ● Ph B Can I /I be > 3x10 ? I1 D I1 D 2 1 12 Oct 2011 5 Dynamical and brightness astrometry Baryc. -
Exoplanet Discovery Methods (1) Direct Imaging Today: Star Wobbles (2) Astrometry → Position (3) Radial Velocity → Velocity
Exoplanet Discovery Methods (1) Direct imaging Today: Star Wobbles (2) Astrometry → position (3) Radial velocity → velocity Later: (4) Transits (5) Gravitational microlensing (6) Pulsar timing Kepler Orbits Kepler 1: Planet orbit is an ellipse with star at one focus Star’s view: (Newton showed this is due to gravity’s inverse-square law). Kepler 2: Planet seeps out equal area in equal time (angular momentum conservation). Planet’s view: Planet at the focus. Star sweeps equal area in equal time Inertial Frame: Star and planet both orbit around the centre of mass. Kepler Orbits M = M" + mp = total mass a = ap + a" = semi # major axis ap mp = a" M" = a M Centre of Mass P = orbit period a b a % P ( 2 a3 = G M ' * Kepler's 3rd Law b & 2$ ) a - b e + = eccentricity 0 = circular 1 = parabolic a ! Astrometry • Look for a periodic “wobble” in the angular position of host star • Light from the star+planet is dominated by star • Measure star’s motion in the plane of the sky due to the orbiting planet • Must correct measurements for parallax and proper motion of star • Doppler (radial velocity) more sensitive to planets close to the star • Astrometry more sensitive to planets far from the star Stellar wobble: Star and planet orbit around centre of mass. Radius of star’s orbit scales with planet’s mass: a m a M * = p p = * a M* + mp a M* + mp Angular displacement for a star at distance d: a & mp ) & a) "# = $ % ( + ( + ! d ' M* * ' d* (Assumes small angles and mp << M* ) ! Scaling to Jupiter and the Sun, this gives: ,1 -1 % mp ( % M ( % a ( % d ( "# $ 0.5 ' * ' + * ' * ' * mas & mJ ) & Msun ) & 5AU) & 10pc) Note: • Units are milliarcseconds -> very small effect • Amplitude increases at large orbital separation, a ! • Amplitude decreases with distance to star d. -
Halometry from Astrometry
Prepared for submission to JCAP Halometry from Astrometry Ken Van Tilburg,a;b Anna-Maria Taki,a Neal Weinera;c aCenter for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003, USA bSchool of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540, USA cCenter for Computational Astrophysics, Flatiron Institute, New York, NY 10010, USA E-mail: [email protected], [email protected], [email protected] Abstract. Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via variable weak gravitational lensing of the apparent motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cat- aloged objects. Astrometry thus offers a new and sensitive probe of collapsed dark matter structures over a wide mass range, from one millionth to several million solar masses. It opens up a window into the spectrum of primordial curvature fluctuations with comoving wavenumbers between 5 Mpc−1 and 105 Mpc−1, scales hitherto poorly constrained. We out- line detection strategies based on three classes of observables—multi-blips, templates, and correlations—that take advantage of correlated effects in the motion of many background light sources that are produced through time-domain gravitational lensing. While existing techniques based on single-source observables such as outliers and mono-blips are best suited for point-like lens targets, our methods offer parametric improvements for extended lens tar- gets such as dark matter subhalos. Multi-blip lensing events may also unveil the existence, arXiv:1804.01991v1 [astro-ph.CO] 5 Apr 2018 location, and mass of planets in the outer reaches of the Solar System, where they would likely have escaped detection by direct imaging. -
The TOI-763 System: Sub-Neptunes Orbiting a Sun-Like Star
MNRAS 000,1–14 (2020) Preprint 31 August 2020 Compiled using MNRAS LATEX style file v3.0 The TOI-763 system: sub-Neptunes orbiting a Sun-like star M. Fridlund1;2?, J. Livingston3, D. Gandolfi4, C. M. Persson2, K. W. F. Lam5, K. G. Stassun6, C. Hellier 7, J. Korth8, A. P. Hatzes9, L. Malavolta10, R. Luque11;12, S. Redfield 13, E. W. Guenther9, S. Albrecht14, O. Barragan15, S. Benatti16, L. Bouma17, J. Cabrera18, W.D. Cochran19;20, Sz. Csizmadia18, F. Dai21;17, H. J. Deeg11;12, M. Esposito9, I. Georgieva2, S. Grziwa8, L. González Cuesta11;12, T. Hirano22, J. M. Jenkins23, P. Kabath24, E. Knudstrup14, D.W. Latham25, S. Mathur11;12, S. E. Mullally32, N. Narita26;27;28;29;11, G. Nowak11;12, A. O. H. Olofsson 2, E. Palle11;12, M. Pätzold8, E. Pompei30, H. Rauer18;5;38, G. Ricker21, F. Rodler30, S. Seager21;31;32, L. M. Serrano4, A. M. S. Smith18, L. Spina33, J. Subjak34;24, P. Tenenbaum35, E.B. Ting23, A. Vanderburg39, R. Vanderspek21, V. Van Eylen36, S. Villanueva21, J. N. Winn17 Authors’ affiliations are shown at the end of the manuscript Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We report the discovery of a planetary system orbiting TOI-763 (aka CD-39 7945), a V = 10:2, high proper motion G-type dwarf star that was photometrically monitored by the TESS space mission in Sector 10. We obtain and model the stellar spectrum and find an object slightly smaller than the Sun, and somewhat older, but with a similar metallicity. Two planet candidates were found in the light curve to be transiting the star. -
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].