Extrasolar Planets : Swiss Society for Astrophysics and Astronomy

463 Pages·2006·18.186 MB·English

by  Patrick Cassen, Tristan Guillot, Andreas Quirrenbach, Ebooks Corporation

Saas-FeeAdvancedCourse 31
P. Cassen T. Guillot A. Quirrenbach
Extrasolar Planets
Saas-Fee Advanced Course 31
Swiss Society for Astrophysics and Astronomy
Edited by D. Queloz, S. Udry, M. Mayor and W. Benz
With 140 Figures, 10 in Color
ABC
PatrickCassen AndreasQuirrenbach
SETIInstitute SterrewachtLeiden
515N.WhismanRd. POBox9513
MountainViewCA94043USA 2300RALeiden,TheNetherlands
[email protected] [email protected]
TristanGuillot
ObservatoiredelaC(cid:244)ted’Azur
BP4229
06304Nice,France
[email protected]
VolumeEditors:
MichelMayor WillyBenz
DidierQueloz Universit(cid:228)tBern,
StephaneUdry PhysikalischesInstitut,
Sidlerstrasse5,
ObservatoiredeGenŁve,
3012Bern,Switzerland
ChemindesMaillettes51,
1290Sauverny,Switzerland
[email protected],
[email protected],
[email protected]
ThisseriesiseditedonbehalfoftheSwissSocietyforAstrophysicsandAstronomy:
SociØtØSuissed’Astrophysiqueetd’Astronomie
ObservatoiredeGenŁve,ch.desMaillettes51,1290Sauverny,Switzerland
Coverpicture: Artwork of “51 Pegasus” made by L.R. Cook shortly after the announcement of the
discovery of the planet. With permission of the artist.
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ISBN-13 978-3-540-29216-6SpringerBerlinHeidelbergNewYork
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Preface
In April 2001 the Swiss Society of Astrophysics and Astronomy (SSAA)
organized its 31st winter “Saas-Fee” course on “Brown Dwarfs and Planets”
in a picturesque resort at Grimentz on the Swiss Alps. The range of topics
mainly focused on extrasolar planets’ science. We entitled these lecture notes
“Extrasolar Planets.”
Researchonextrasolarplanetsisoneofthemostexcitingfieldsofactivity
in astrophysics. In just a decade a huge step has been made from the early
speculations on the existence of planets orbiting “other stars” to the first
discoveries and the characterization of extrasolar planets. This breakthrough
is the result of the growing interest of a large community of researchers as
well as the development of a wide range of new observation techniques and
facilities. We organized the 31st winter course to cover all relevant aspects of
this new field: observation and detection techniques, physics of their interior,
and physics of their formation. We were very happy to have three senior
lecturers, Andreas Quirrenbach, Tristan Guillot, and Patrick Cassen, cover
thesethreesubjects.Theyprovidedinformationtomorethan100participants
andalsogaveupdatedcomprehensivecoursematerials,whichisachallenging
taskconsideringtherapiddevelopmentofthisfieldofresearch.Wehopethat
the level of details and the comprehensive view offered by authors will be
appreciatedasacomprehensivedetailedintroductiontothisexcitingsubject.
We would like to warmly thank our three speakers for the high standard
of their lectures and notes, as well as their discussion with students. We also
thank all participants for their participation, kindness, and enthusiasm in
taking part in the events organized. We thank Dominique Briguet of “A La
Marena”forhishospitalityandhishelpwiththelocalorganization.Wewould
also like to warmly thank Elisabeth Teichamann, our course secretary, who
gave us immense support during the preparation of the meeting as well as
duringthecourse.Thiscoursehasbeenmadepossiblethankstoagrantfrom
the Swiss Academy of Sciences.
Geneva Didier Queloz
June 2005 St´ephane Udry
Willy Benz
Michel Mayor
Ourthreelecturers:(left)PatCassen,(middle)AndreasQuirrenbach,(right)Tristan
Guillot

Contents
Detection and Characterization
of Extrasolar Planets
A. Quirrenbach .................................................. 1
1 Methods of Planet Detection................................... 1
1.1 The Quest for Planets Around Other Stars.................. 1
1.2 What is a Planet? ....................................... 3
1.3 Pulsar Planets........................................... 6
1.4 Overview of Planet Detection Methods ..................... 9
1.5 “Exotic” Concepts for Planet Detection .................... 11
1.6 The Search for Extraterrestrial Intelligence.................. 15
2 Planet-Forming Disks ......................................... 21
2.1 Star Formation: the General Framework .................... 22
2.2 Observations of Dusty Disks .............................. 24
2.3 Observations of Infalling Material and Evidence
for Extrasolar Planetesimals............................... 31
3 The Currently Known Extrasolar Planets........................ 35
3.1 The First Hundred Planets Around Solar-Type Stars......... 35
3.2 Distribution of Masses and Orbital Radii ................... 39
3.3 Orbital Eccentricities..................................... 44
3.4 Properties of the Parent Stars ............................. 47
3.5 Systems with Multiple Planets ............................ 51
3.6 Interactions Between the Planets in Multiple Systems ........ 58
4 Radial-Velocity Surveys ....................................... 62
4.1 The Radial-Velocity Technique ............................ 62
4.2 Limitations of the Radial-Velocity Precision................. 64
4.3 Spectrograph Design ..................................... 71
4.4 Radial-Velocity Surveys .................................. 75
5 Gravitational Microlensing .................................... 76
5.1 Theory of Gravitational Microlensing....................... 77
5.2 Planetary Systems as Gravitational Lenses.................. 83
5.3 Microlensing Planet Searches.............................. 92
X Contents
5.4 Astrometric and Interferometric Observations
of Microlensing Events ................................... 96
6 Planetary Transits and Searches for Light
Reflected by Planets ..........................................101
6.1 The Geometry of Transits.................................101
6.2 Photometric Error Sources................................109
6.3 HD209458 ..............................................112
6.4 Photometric Planet Searches ..............................115
6.5 Photometric Space Missions...............................122
6.6 Searches for the Light Reflected by the Planet...............123
7 The Effects of Atmospheric Turbulence
on Astronomical Observations..................................130
7.1 The Kolmogorov Turbulence Model ........................130
7.2 Wave Propagation Through Turbulence.....................133
7.3 The Effect of Turbulence on Astronomical Images............135
7.4 Fried Parameter and Strehl Ratio..........................137
7.5 Temporal Evolution of Atmospheric Turbulence .............139
7.6 Temporal Structure Function and Power Spectra.............139
7.7 Angular Anisoplanatism ..................................140
7.8 Scintillation.............................................141
7.9 Turbulence and Wind Profiles .............................142
8 Introduction to Optical Interferometry ..........................143
8.1 Schematic Design of an Optical Interferometer...............144
8.2 Beam Combination Concepts..............................146
8.3 Source Coherence and Interferometer Response ..............147
8.4 Bandwidth and Interferometric Field-of-View................148
8.5 Fringe Detection.........................................148
8.6 Phase Decorrelation Mechanisms ..........................153
9 Astrometry with Interferometry ................................160
9.1 Astrometric Signature of Low-Mass Companions.............160
9.2 Upper Mass Limits and Astrometric Detection of Gl876B ....161
9.3 Astrometric Measurements with an Interferometer ...........162
9.4 Atmospheric Limitations of Astrometry.....................164
9.5 Dual-Star Interferometry .................................168
9.6 Interferometric Astrometry from Space .....................171
9.7 Astrometric Planet Surveys ...............................175
9.8 Astrometric References ...................................176
9.9 The Differential-Phase Method ............................179
10 Nulling Interferometry ........................................181
10.1 Principles of Nulling .....................................181
10.2 Implementation of Achromatic Phase Shifts .................189
10.3 Nulling Interferometry from the Ground ....................195
10.4 Design of Nulling Arrays..................................201
11 Appendix: Useful Definitions and Results from Fourier Theory .....210
References ......................................................212
Contents XI
Physics of Substellar Objects Interiors,
Atmospheres, Evolution
T. Guillot.......................................................243
1 Introduction .................................................243
2 “Our” Giant Planets as a Basis for the Study
of Substellar Objects..........................................243
2.1 Origins: Role of the Giant Planets for Planet Formation ......243
2.2 Gravity Field and Global Properties........................244
2.3 Magnetic Fields .........................................246
2.4 Atmospheric Composition.................................246
2.5 Energy Balance and Atmospheric Temperature Profiles .......247
2.6 Spectra.................................................250
2.7 Atmospheric Dynamics: Winds and Weather ................251
2.8 Moons and Rings ........................................251
2.9 Oscillations .............................................252
3 Basic Equations, Gravitational Moments and Interior Structures ...253
3.1 Hydrostatic Equilibrium ..................................253
3.2 Boundary Conditions.....................................253
3.3 Simple Solutions.........................................255
3.4 Mass–Radius Relation....................................257
3.5 Rotation and the Figures of Planets........................260
3.6 Equations of Evolution ...................................265
4 Equations of State............................................266
4.1 Basic Considerations .....................................266
4.2 Experiments and Theoretical Hydrogen EOSs ...............272
4.3 Other Elements..........................................277
5 Opacities and Heat Transport..................................279
5.1 Radiation Absorption – Basic Considerations................280
5.2 Rosseland Opacities......................................281
5.3 Heat Transport..........................................289
6 Interior Structures of our Giant Planets:
Numerical Integrations and Results .............................296
6.1 Basic Principles .........................................296
6.2 Jupiter and Saturn.......................................296
6.3 Uranus and Neptune .....................................304
6.4 Consequences for Formation Models........................305
7 Evolution of Giant Planets and Brown Dwarfs ...................309
7.1 The Virial Theorem......................................310
7.2 A Semi-Analytical Model .................................312
7.3 Evolution of Jupiter and Saturn ...........................315
7.4 From Giant Planets to Brown Dwarfs ......................320
7.5 Extrasolar Giant Planets .................................326
8 Spectra and Atmospheres .....................................326
8.1 Direct Observations of Substellar Objects...................326
8.2 Atmospheric Models: Importance of Condensation ...........334