The Exoplanets Revolution , livre ebook
215
pages
English
Ebooks
2020
Obtenez un accès à la bibliothèque pour le consulter en ligne En savoir plus
Découvre YouScribe en t'inscrivant gratuitement
Découvre YouScribe en t'inscrivant gratuitement
215
pages
English
Ebooks
2020
Obtenez un accès à la bibliothèque pour le consulter en ligne En savoir plus
Publié par
Date de parution
29 juillet 2020
Nombre de lectures
6
EAN13
9782759822119
Langue
English
Poids de l'ouvrage
3 Mo
More than 4300 planets around nearby stars! Who could have imagined this extraordinary harvest only thirty years ago? As the vast majority of stars are surrounded by planets, we can surmise that there must be more than a hundred billion planets in our Galaxy. The Solar system is therefore very far from unique. However, it looks quite different from most of the external systems that we know today, but the variety of planetary systems is such that it is difficult to conclude that the Solar System is truly particular. Understanding how diverse planet systems were formed and how they evolved, studying the nature of exoplanets and their atmospheres, are challenges that hundreds of researchers around the world are working on. Does any of these planets harbor life? We do not yet have an answer, but the new means of observation and analysis that astronomers have and will soon have at their disposal are so powerful that they could give a first answer in a few decades, and perhaps even in a few years if we are lucky.
This book gives a comprehensive vision of this complex and fascinating area of research, presented in a simple and lively way.
Publié par
Date de parution
29 juillet 2020
Nombre de lectures
6
EAN13
9782759822119
Langue
English
Poids de l'ouvrage
3 Mo
www.edpsciences.org
The Exoplanet Revolution
The Exoplanet Revolution
J. Lequeux,
James Lequeux, Thérèse Encrenaz and Fabienne Casoli
CURRENT NATURAL SCIENCES
The Exoplanet Revolution
James Lequeux, Thérèse Encrenaz and Fabienne Casoli
ore than 4300 planets around nearby stars! Who could have îmagîned thîs bîllîonMplanets în our Galaxy. The Solar system îs thereore very ar rom unîque. However, ît extraordînary harvest only thîrty years ago? As the vast majorîty o stars are surrounded by planets, we can surmîse that there must be more than a hundred looks quîte dîferent rom most o the external systems that we know today, but the varîety o planetary systems îs such that ît îs dîIcult to conclude that the Solar System îs truly partîcular. Understandîng how dîverse planet systems were ormed and how they evolved, studyîng the nature o exoplanets and theîr atmospheres, are challenges that hundreds o researchers around the world are workîng on. Does any o these planets harbor lîe? We do not yet have an answer, but the new means o observatîon and analysîs that astronomers have and wîll soon have at theîr dîsposal are so powerul that they could gîve a irst answer în a ew decades, and perhaps even în a ew years î we are lucky. Thîs book gîves a comprehensîve vîsîon o thîs complex and ascînatîng area o research, presented în a sîmple and lîvely way.
James Lequeuxîs an emerîtus astronomer at the Parîs Observatory. Hîs domaîns o expertîse are the înterstellar matter and the evolutîon o stars and galaxîes. He has dîrected the Marseîlles Observatory. He has wrîtten many books on the hîstory o astronomy, and several popular books.
Thérèse Encrenazîs an expert în planetary atmospheres. She has dîrected the Department o Space Research at the Parîs Observatory and was adjunct Presîdent o thîs Observatory. She has wrîtten many textbooks and popular books.
Fabienne Casoliîs Presîdent o the Parîs Observatory. Her specîalty îs radîoastronomy. She has been adjunct dîrector o the French Natîonal Center or Space Studîes and o the Natîonal ïnstîtute o Scîences o the Unîverse, and dîrected the ïnstîtute o Space Astronomy în Orsay.
www.edpsciences.org
9 782759 822102
ISBN :9782759822102
CURRENT NATURAL SCIENCES
J. Lequeux, T. Encrenaz and F. Casoli
The Exoplanet Revolution
C U R R E N T N A T U R A L S C I E N C E S EDP Sciences
Cover image: a planet just formed in the disk of gas and dust surrounding the dwarf star PDS 70. In this near-infrared, high-resolution image, the planet is seen as a bright point inside the remains of the disk. The star itself, at the center, is occulted by a mask. © European Southern Observatory, A. Müller et al. Printed in France © 2020, EDP Sciences, 17 avenue du Hoggar, BP 112, Parc d’activités de Courtabœuf, 91944 Les Ulis Cedex A This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broad-casting, reproduction on microfilms or in other ways, and storage in data bank. Duplication of this publication or parts thereof is only permitted under the provisions of the French Copyright law of March 11, 1957. Violations fall under the prosecution act of the French Copyright law. ISBN (print): 978-2-7598-2210-2 - ISBN (ebook): 978-2-7598-2211-9
Table of Contents
Introduction Chapter 1. The prehistory of exoplanets Fîst îdéas and spécûlatîons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé évolûtîon of concépts on thé fomatîon of thé Sola Systém . . . . . . Thé dîscovéy of potoplanétay dîsks . . . . . . . . . . . . . . . . . . . . . . . . . Thé fîst attémpts to détéct éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 2. The first detections An ûnéxpéctéd dîscovéy: planéts aoûnd a pûlsa! . . . . . . . . . . . . . . . . 1995: Thé fîst planét aoûnd a sta lîké oûs! . . . . . . . . . . . . . . . . . . . Thé sûccéss of vélocîméty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 3. The method of transits What îs a planétay tansît? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Obsévatîons fom thé Eath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé Spacé Aé . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé CoRoT mîssîon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé Képlé Mîssîon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pîmay and Séconday Tansîts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tansmîssîon spéctoscopy (pîmay tansît) . . . . . . . . . . . . . . . . Emîssîon spéctoscopy (séconday tansît) . . . . . . . . . . . . . . . . . . Gavîtatîonal tansîts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 4. Detecting and viewing exoplanets Advantaés and lîmîtatîons of îndîéct méthods of détéctîon . . . . . . . . . Thé tansît méthod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exoplanéts détéctéd as avîtatîonal mîcolénsés . . . . . . . . . . . . . Exoplanéts détéctéd by vélocîméty o astométy . . . . . . . . . . . . Dîéct obsévatîon: a véy dîffîcûlt poblém . . . . . . . . . . . . . . . . . . . . . Coonoaphy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé black-fîné întéféomété . . . . . . . . . . . . . . . . . . . . . . . . . How to obtaîn péféct îmaés: adaptîvé optîcs . . . . . . . . . . . . . . . Combînéd coonoaphy and adaptîvé optîcs . . . . . . . . . . . . . . . . A néw tack fo thé fûtûé: thé séach fo éxoplanéts în thé adîo domaîn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 5 5 8 11 12 17 19 19 21 27 31 33 33 36 37 37 38 40 41 43 44 46
47 47 47 48 49 50 51 52 53 55
57 57
IV
Thé Exoplanét Révolûtîon
Chapter 5. The variety of exoplanets Thé oûtstandîn ésûlts of thé last twénty yéas. . . . . . . . . . . . . . . . . . A mûltîtûdé of éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gîant éxoplanéts véy closé to théî stas . . . . . . . . . . . . . . . . . . Obîts of all kînds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Many mûltîplé systéms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planéts aoûnd doûblé stas . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé dîfféént classés of éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . . . . . Hot and Cold Jûpîtés . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sûpé-Eaths and Néptûnés . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eaths and Habîtablé Planéts . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 6. The birth of stars and protoplanetary disks Potostas, jéts and dîsks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé potoplanétay dîsks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé îcé lînés în potoplanétay dîsks . . . . . . . . . . . . . . . . . . . . . . . . . . Planét-dîsk întéactîons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 7. Formation and evolution of planetary systems Thé fomatîon of planéts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé évolûtîon of planétay systéms: what doés thé Sola Systém téach ûs? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Why no sûpé-Eaths în thé Sola Systém? . . . . . . . . . . . . . . . . . . . . . Expélléd planéts, îsolatéd éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . . . What fûtûé fo thé Sola Systém? . . . . . . . . . . . . . . . . . . . . . . . . . . . What conséqûéncés fo oû ûndéstandîn of éxoplanétay systéms?. . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 8. The physical nature of exoplanets Thé obsévablés . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé fîst méasûéménts of thé atmosphéîc composîtîon of hot Jûpîtés . . Possîblé caûsés of dépatûé fom thémochémîcal éqûîlîbîûm. . . . . . . . Cloûds and mîsts on éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spéctoscopîc méasûéménts of sûpé-Eaths and éxo-Néptûnés în tansîtSpéctoscopy of éxoplanéts fom thé oûnd . . . . . . . . . . . . . . . . . . . . Phasé cûvés and atmosphéîc cîcûlatîon of éxoplanéts . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 9. Around Exoplanets Thé éxocométs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gîant îns aoûnd an éxoplanét? . . . . . . . . . . . . . . . . . . . . . . . . . . . . A satéllîté? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 10. Life on exoplanets? What îs lîfé? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thé émééncé of lîfé on Eath. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lîfé élséwhéé în thé Sola Systém? . . . . . . . . . . . . . . . . . . . . . . . . . . How to détéct lîfé on éxoplanéts? . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
59 59 59 59 60 61 62 62 64 67 70 73
75 75 78 82 84 87 89 89
92 98 98 100 102 104
107 107 111 114 116 116 118 120 121
123 124 127 129 130
131 132 133 141 144 149
Tablé of Conténts
Chapter 11. Exploring Exoplanets: What Prospects? Habîtablé planéts, înhabîtéd planéts: a dîffîcûlt poblém . . . . . . . . . . . . Moé planéts, and smallé onés, to éxploé thé dîvésîty of planétay systéms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Néw lîht on îant planéts: astométy and îmaéy . . . . . . . . . . . . . . . Stûdyîn thé atmosphéés of éxoplanéts . . . . . . . . . . . . . . . . . . . . . . . Towads analos of thé Eath-Sûn systém: afté 2030? . . . . . . . . . . . . . Alpha Céntaûî: othé planéts?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 12. Communicating with other worlds? Thé pobabîlîty of éxîsténcé of advancéd cîvîlîzatîons on othé planéts . . Thé SETI Pojécts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Méssaés to thé Unîvésé . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bîblîoaphy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix 1: The planets of the Solar System
Appendix 2: A Selection of Exoplanets
Appendix 3: Some useful data
Appendix 4: The nomenclature of stars and exoplanets Glossary Acronyms Index
V
151 151
154 159 162 165 167
169 169 171 174 177
179 181 189 191 193 199 203
Introduction
Amon thé éat astonomîcal dîscovéîés of thé last céntûy, thé most éxcîtîn în thé éyés of thé énéal pûblîc was ûndoûbtédly that of a planét aoûnd anothé sta than thé Sûn. It datés back to 1995. To say thé tûth, ît was éxpéctéd that sûch a dîscovéy woûld occû somé day, bécaûsé théé was no éason why thé Sola Systém shoûld bé thé only oné of îts kînd. Fom thé tîmé of Antîqûîty, thén wîth Nîcolas dé Cûés and Gîodano Bûno at thé énd of thé sîxtéénth céntûy, théé was spécûlatîon aboût thé possîbîlîty of planétay systéms sîmîla to oûs aoûnd othé stas. It was only nécéssay that thé téchnîqûés of obsévatîon had poésséd sûffîcîéntly to allow thé dîscovéy. Thîs îs what dîffééntîatés thé dîscovéy of thé éxtasola planéts, as wéll as that of thé Hîs boson în 2012 and thé avîtatîonal wavés în 2015, fom that of thé ûnéxpéctéd astonomîcal objécts that aé thé dak matté (dîscovééd în 1937), thé X-ay soûcés (1965), thé qûasas (1963), thé fossîl adîatîon fom thé Unîvésé (1965), thé pûlsas (1965) and thé soûcés of amma-ay bûsts (1968), to namé only thé most spéctacûla. Thé sûpîsé was qûîté dîfféént: thé néw planét, whîch has a mass closé to that of Jûpîté, avîtatés aoûnd thé sta 51 Péasî în only foû days and îs twénty tîmés léss dîstant fom thîs sta than thé Eath îs fom thé Sûn, whîch makés ît a véy hot objéct. Théé îs nothîn sîmîla în thé Sola Systém, whîch was îmmédîatély déadéd fom îts statûs as a po-totypé of possîblé planétay systéms. Soon othé éxoplanéts (a néoloîsm that sééms accéptéd today) wéé dîscovééd. Théy léd to othé sûpîsés: somé havé véy élonatéd éllîptîcal obîts, whîch îs not thé casé of any of thé planéts that aé famîlîa to ûs. Sûpé-Eaths, and mînî-Néptûnés, wîth a mass întémédîaté bétwéén that of thé Eath and that of Jûpîté, aé fé-qûént, thoûh ûnpaalléléd în thé Sola Systém. Wé havé also foûnd planéts obîtîn aoûnd systéms of doûblé stas. Moé than 4200 éxoplanéts havé béén dîscovééd today. Théy show an astonîshîn vaîéty în théî massés, în théî obîts and în théî physîcal popétîés. Up to sévén planéts havé béén détéctéd în somé planétay sys-téms. Most of thé known éxoplanéts aé mûch closé to théî stas than thé Eath îs to thé Sûn, whîch was a bî sûpîsé; howévé, thîs may bé only a conséqûéncé of thé lîmîts of oû obsévatîons, fo thésé planéts aé éasîé to détéct than thé dîstant onés. Thé latté, howévé, éxîst: théy aé thé only
2
Thé Exoplanét Révolûtîon
onés whosé îmaé can bé madé wîthoût béîn too împédéd by thé lîht of thé sta, whîch can bé a bîllîon tîmés moé înténsé. Théé aé évén îsolatéd planéts cîcûlatîn în thé Mîlky Way: havé théy béén éjéctéd fom a plané-tay systém by somé méchanîsm? All thîs qûéstîonéd thé îdéas wé had aboût thé bîth and évolûtîon of planétay systéms. It was lon bélîévéd wîth Laplacé that thé planéts wéé at thé dîstancé of thé sta to whîch théy wéé bon, and foméd an almost îmmûtablé systém. Yét somé éséachés havé shown în thé 1980s that thîs coûld not bé so bécaûsé of thé avîtatîonal întéactîon bétwéén thé planéts and what émaîns of thé as and dûst dîsk whéé théy wéé bon at thé samé tîmé as thé céntal sta. Moéové, thé dîscovéés of thé fîst éxoplanét îmmédîatély éalîzéd that ît mûst havé béén foméd fa fom thé sta, and thén had înîtîatéd a mîatîon that had movéd ît véy closé to thîs sta. Thîs obsévatîon, toéthé wîth othé ûnéxpéctéd popétîés of éxoplanéts, léd to an înténsé théoétîcal actîvîty, béînnîn wîth thé popétîés of thé Sola Systém that wéé thoûht to bé wéll ûndéstood. Thé ésûlts aé astonîshîn: ît appéas that thé pésént aspéct of thé Sola Systém dépénds éntîély on thé béhavîo of îts two bîést planéts, Jûpîté and Satûn, and woûld havé béén véy dîfféént îf only oné had béén pésént. Moéové, thé Sola Systém, lîké othé planétay systéms, îs not îmmûtablé, and coûld stîll ûndéo majo tansfomatîons on thé scalé of sévéal bîllîon yéas: oné coûld, fo éxamplé, wîtnéss thé éjéctîon of a planét o a collîsîon bétwéén two planéts, an othéwîsé ûnpédîctablé béhavîo bécaûsé ît îs domînatéd by chaos. Undéstandîn thé oîîn and stûctûé of éxoplanét systéms, fo whîch wé havé mûch léss data than fo thé Sola Systém, îs évén moé chal-lénîn: hûndéds of éséachés aoûnd thé wold aé cûéntly wokîn on thésé îssûés. Thé séach fo éxoplanéts has tîééd, and stîll caûsés, éat advancés în astonomîcal înstûméntatîon. Thé laést téléscopés on thé oûnd and în spacé aé ûséd to obsévé thém, and many poams aé éntîély déd-îcatéd to théî éséach and stûdy. It îs now possîblé to havé an îdéa of thé témpéatûé and chémîcal composîtîon of thé atmosphéé of thé îant éxoplanéts, éspécîally thé “hot Jûpîtés” whîch avîtaté closé to théî stas. Howévé, wé aé not yét to thîs poînt fo thé léss massîvé planéts, whîch aé thé onés that coûld shélté lîfé. Indééd, thé most éxcîtîn pospéct opénéd by thé dîscovéy of éxtasola planéts îs thé séach fo planéts locatéd néîthé too closé no too fa fom théî sta, whéé lîfé coûld dévélop. Oû anthopocéntîsm sûésts that théy mûst havé a mass closé to that of thé Eath, bût în éalîty nothîn pévénts moé massîvé planéts – sûpé-Eaths – fom cayîn lîfé. Whîlé planéts sîmîla to thé Eath aé stîll dîffîcûlt to dîscové, wé aléady know a lot of sûpé-Eaths, somé of whîch appéa to bé în favoablé condîtîons. To chaactéîzé thém and to look fo clûés aboût somé fom of lîfé aé somé of thé maîn challénés of thé comîn yéas. Fo cléa answés, ît wîll pobably
