Exoplanet Detection Techniques
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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. -
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. -
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. -
Arxiv:Astro-Ph/0609369 V2 15 Sep 2006 Ahntnd,54 Ra Rnhr.N,Wsigo DC, Washington NW, Rd
Draft version September 18, 2006 – VERSION Accepted for publication in ApJ A Preprint typeset using LTEX style emulateapj v. 12/14/05 HAT-P-1b: A LARGE-RADIUS, LOW-DENSITY EXOPLANET TRANSITING ONE MEMBER OF A STELLAR BINARY† ⋆ G. A.´ Bakos1,2, R. W. Noyes1, G. Kovacs´ 3, D. W. Latham1, D. D. Sasselov1, G. Torres1, D. A. Fischer6, R. P. Stefanik1, B. Sato7, J. A. Johnson8, A. Pal´ 4,1, G. W. Marcy8, R. P. Butler9, G. A. Esquerdo1, K. Z. Stanek10, J. Laz´ ar´ 5, I. Papp5, P. Sari´ 5 & B. Sipocz˝ 4,1 Draft version September 18, 2006 – VERSION Accepted for publication in ApJ ABSTRACT Using small automated telescopes in Arizona and Hawaii, the HATNet project has detected an object transiting one member of the double star system ADS 16402. This system is a pair of G0 main-sequence stars with age about 3 Gyr at a distance of ∼139 pc and projected separation of ∼1550 AU. The transit signal has a period of 4.46529 days and depth of 0.015 mag. From follow-up photometry and spectroscopy, we find that the object is a “hot Jupiter” planet with mass about 0.53 MJ and radius ∼1.36 RJ traveling in an orbit with semimajor axis 0.055 AU and inclination about 85◦.9, thus transiting the star at impact parameter 0.74 of the stellar radius. Based on a data set spanning three years, ephemerides for the transit center are: TC = 2453984.397+ Ntr ∗ 4.46529. The planet, designated HAT-P-1b, appears to be at least as large in radius, and smaller in mean density, than any previously-known planet. -
The Search for Another Earth – Part II
GENERAL ARTICLE The Search for Another Earth – Part II Sujan Sengupta In the first part, we discussed the various methods for the detection of planets outside the solar system known as the exoplanets. In this part, we will describe various kinds of exoplanets. The habitable planets discovered so far and the present status of our search for a habitable planet similar to the Earth will also be discussed. Sujan Sengupta is an 1. Introduction astrophysicist at Indian Institute of Astrophysics, Bengaluru. He works on the The first confirmed exoplanet around a solar type of star, 51 Pe- detection, characterisation 1 gasi b was discovered in 1995 using the radial velocity method. and habitability of extra-solar Subsequently, a large number of exoplanets were discovered by planets and extra-solar this method, and a few were discovered using transit and gravi- moons. tational lensing methods. Ground-based telescopes were used for these discoveries and the search region was confined to about 300 light-years from the Earth. On December 27, 2006, the European Space Agency launched 1The movement of the star a space telescope called CoRoT (Convection, Rotation and plan- towards the observer due to etary Transits) and on March 6, 2009, NASA launched another the gravitational effect of the space telescope called Kepler2 to hunt for exoplanets. Conse- planet. See Sujan Sengupta, The Search for Another Earth, quently, the search extended to about 3000 light-years. Both Resonance, Vol.21, No.7, these telescopes used the transit method in order to detect exo- pp.641–652, 2016. planets. Although Kepler’s field of view was only 105 square de- grees along the Cygnus arm of the Milky Way Galaxy, it detected a whooping 2326 exoplanets out of a total 3493 discovered till 2Kepler Telescope has a pri- date. -
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. -
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. -
Livre-Ovni.Pdf
UN MONDE BIZARRE Le livre des étranges Objets Volants Non Identifiés Chapitre 1 Paranormal Le paranormal est un terme utilisé pour qualifier un en- mé n'est pas considéré comme paranormal par les semble de phénomènes dont les causes ou mécanismes neuroscientifiques) ; ne sont apparemment pas explicables par des lois scien- tifiques établies. Le préfixe « para » désignant quelque • Les différents moyens de communication avec les chose qui est à côté de la norme, la norme étant ici le morts : naturels (médiumnité, nécromancie) ou ar- consensus scientifique d'une époque. Un phénomène est tificiels (la transcommunication instrumentale telle qualifié de paranormal lorsqu'il ne semble pas pouvoir que les voix électroniques); être expliqué par les lois naturelles connues, laissant ain- si le champ libre à de nouvelles recherches empiriques, à • Les apparitions de l'au-delà (fantômes, revenants, des interprétations, à des suppositions et à l'imaginaire. ectoplasmes, poltergeists, etc.) ; Les initiateurs de la parapsychologie se sont donné comme objectif d'étudier d'une manière scientifique • la cryptozoologie (qui étudie l'existence d'espèce in- ce qu'ils considèrent comme des perceptions extra- connues) : classification assez injuste, car l'objet de sensorielles et de la psychokinèse. Malgré l'existence de la cryptozoologie est moins de cultiver les mythes laboratoires de parapsychologie dans certaines universi- que de chercher s’il y a ou non une espèce animale tés, notamment en Grande-Bretagne, le paranormal est inconnue réelle derrière une légende ; généralement considéré comme un sujet d'étude peu sé- rieux. Il est en revanche parfois associé a des activités • Le phénomène ovni et ses dérivés (cercle de culture). -
EPSC2018-126, 2018 European Planetary Science Congress 2018 Eeuropeapn Planetarsy Science Ccongress C Author(S) 2018
EPSC Abstracts Vol. 12, EPSC2018-126, 2018 European Planetary Science Congress 2018 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2018 Stellar wind interaction with the expanding atmosphere of Gliese 436b A.G. Berezutskiy (1), I.F. Shaikhislamov (1), M.L. Khodachenko (2,3) and I.B. Miroshnichenko (1,4) (1) Institute of Laser Physics, Siberian Brunch Russian Academy of Science, Novosibirsk, Russia; (2) Space Research Institute, Austrian Academy of Science, Graz, Austria; (3) Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia (4) Novosibirsk State Technical University, Novosibirsk, Russia ([email protected]) Abstract the escaping planetary upper atmospheric material are also taken into account. We study an exosphere of a Neptune-size exoplanet Gliese 436b, orbiting the red dwarf at an extremely 3. Results close distance (0.028 au), taking into account its interaction with the stellar wind plasma flow. It was At the initial state of the simulations, the atmosphere shown that Gliese 436 b has a bowshock region of Gliese 436b is assumed to consist of the molecular between planetary and stellar wind which localized hydrogen and helium atoms at a ratio NHe / NH2 = 1/5 on the distance of ~33 Rp, where density of planetary with the temperature 750 K. We consider the case of -3 atoms slightly dominates over the protons. a weak stellar wind (SW) with nsw=100 cm , Tsw=1 МК, Vsw=70 km/s, which is much less intense than 1. Introduction the solar wind. Because of this fact, , we did not consider generation of Energetic Neutral Atoms The modelled planet Gliese 436b has a mass (ENAs). -
Simulating (Sub)Millimeter Observations of Exoplanet Atmospheres in Search of Water
University of Groningen Kapteyn Astronomical Institute Simulating (Sub)Millimeter Observations of Exoplanet Atmospheres in Search of Water September 5, 2018 Author: N.O. Oberg Supervisor: Prof. Dr. F.F.S. van der Tak Abstract Context: Spectroscopic characterization of exoplanetary atmospheres is a field still in its in- fancy. The detection of molecular spectral features in the atmosphere of several hot-Jupiters and hot-Neptunes has led to the preliminary identification of atmospheric H2O. The Atacama Large Millimiter/Submillimeter Array is particularly well suited in the search for extraterrestrial water, considering its wavelength coverage, sensitivity, resolving power and spectral resolution. Aims: Our aim is to determine the detectability of various spectroscopic signatures of H2O in the (sub)millimeter by a range of current and future observatories and the suitability of (sub)millimeter astronomy for the detection and characterization of exoplanets. Methods: We have created an atmospheric modeling framework based on the HAPI radiative transfer code. We have generated planetary spectra in the (sub)millimeter regime, covering a wide variety of possible exoplanet properties and atmospheric compositions. We have set limits on the detectability of these spectral features and of the planets themselves with emphasis on ALMA. We estimate the capabilities required to study exoplanet atmospheres directly in the (sub)millimeter by using a custom sensitivity calculator. Results: Even trace abundances of atmospheric water vapor can cause high-contrast spectral ab- sorption features in (sub)millimeter transmission spectra of exoplanets, however stellar (sub) millime- ter brightness is insufficient for transit spectroscopy with modern instruments. Excess stellar (sub) millimeter emission due to activity is unlikely to significantly enhance the detectability of planets in transit except in select pre-main-sequence stars. -
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]. -
Planets Beyond the Solar System
Understanding exoplanets in the era of large telescopes Yogesh C. Joshi Aryabhatta Research Institute of Observational Sciences (ARIES), India 1 Detection of exoplanets: Transit and Radial Velocity Method When planet passes in front of the stellar disc, it blocks light and we see a dip (loss of flux) in the light curve. 2 ΔF/F0 = (Rp/R*) When planet revolves around the star, the star wobbles and we see a variation in the radial motion. ( ⅓ 1 2G Mp sin i K = ( ⅔ 2 ½ P Ms (1 – e ) Exoplanets: present status More than 4100 exoplanets are already detected till date Planetary system close to solar system: TRAPPIST-1 4 Planetary system close to solar system: TRAPPIST-1 • TRAPPIST-1b, the innermost planet, is likely to have a rocky core, surrounded by an atmosphere much thicker than Earth's. • TRAPPIST-1c may also have a rocky interior, but with a thinner atmosphere than planet b. • TRAPPIST-1d is the lightest of the planets – about 30 percent the mass of Earth. • TRAPPIST-1e is the only planet in the system slightly denser than Earth, suggesting it may have a denser iron core than our home planet. In terms of size, density and the amount of radiation it receives from its star, this is the most similar planet to the Earth. • TRAPPIST-1f, g and h are far enough from the host star that water could be frozen as ice across their surfaces. If they have thin atmospheres, 5 they would be unlikely to contain heavy molecules of Earth, such as CO2. Exoplanetary science with large telescope High-precision photometry High-resolution spectroscopy 6 Radial Velocity through high-resolution spectroscopy HD 85512: 3.6 M⨁ transiting exoplanet Credit: ESPRESSO consortium (2018) 7 Studying the stellar rotation WASP-14b (Joshi et al.