Astrometric search for extrasolar planets in stellar multiple systems [Elektronische Ressource] / Tristan Alexander Röll. Gutachter: Ralph Neuhäuser ; Thomas Preibisch

Sujets

• Astronomie

Informations

• Publié par: friedrich-schiller-universitat_jena
• Publié le: 01 janvier 2011
• Nombre de lectures: 53
• Langue: English
• Poids de l'ouvrage: 10 Mo

Extrait

Astrometric search
for extrasolar planets
in stellar multiple systems
Dissertation
submitted in partial fulfillment
of the requirements for the degree of
doctor rerum naturalium (Dr. rer. nat.)
submitted to the
faculty council for physics and astronomy
of the Friedrich-Schiller-University Jena
by graduate physicist
Tristan Alexander Röll,
born at 30.01.1981 in Friedrichroda.Referees:
1. Prof. Dr. Ralph Neuhäuser (FSU Jena, Germany)
2. Prof. Dr. Thomas Preibisch (LMU München, Germany)
3. Dr. Guillermo Torres (CfA Harvard, Boston, USA)
Day of disputation: 17 May 2011In Memoriam
Siegmund Meisch
?
15.11.1951 † 01.08.2009
“Gehe nicht, wohin der Weg führen mag,
sondern dorthin, wo kein Weg ist,
und hinterlasse eine Spur ... ”
Jean PaulContents
1. Introduction 1
1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. Aims of this work . . . . . . . . . . . . . . . . . . . . 4
1.3. Astrometry - a short review . . . . . . . . . . . . . . . 6
1.4. Search for extrasolar planets . . . . . . . . . . . . . . 9
1.5. Extrasolar planets in stellar multiple systems . . . . . 13
2. Observational challenges 29
2.1. Astrometric method . . . . . . . . . . . . . . . . . . . 30
2.2. Stellar effects . . . . . . . . . . . . . . . . . . . . . . 33
2.2.1. Differential parallaxe . . . . . . . . . . . . . . 33
2.2.2. Stellar activity . . . . . . . . . . . . . . . . . . 35
2.3. Atmospheric effects . . . . . . . . . . . . . . . . . . . 36
2.3.1. Atmospheric turbulences . . . . . . . . . . . . 36
2.3.2. Differential atmospheric refraction . . . . . . . 40
2.4. Relativistic effects . . . . . . . . . . . . . . . . . . . . 45
2.4.1. Differential stellar aberration . . . . . . . . . . 45
2.4.2.tial gravitational light deflection . . . . 49
2.5. Target and instrument selection . . . . . . . . . . . . 51
2.5.1. Instrument requirements . . . . . . . . . . . . 51
2.5.2. Targetts . . . . . . . . . . . . . . . 53
3. Data analysis 57
3.1. Object detection . . . . . . . . . . . . . . . . . . . . . 57
3.2. Statistical analysis . . . . . . . . . . . . . . . . . . . . 58
3.3. Check for an astrometric signal . . . . . . . . . . . . . 59
3.4. Speckle interferometry . . . . . . . . . . . . . . . . . . 62
iContents
4. Calibration 63
4.1. Calibration clusters . . . . . . . . . . . . . . . . . . . 64
4.2. Iterative calibration cycle . . . . . . . . . . . . . . . . 65
4.3. Geometric field distortions . . . . . . . . . . . . . . . 67
5. Results 71
5.1. Astrometric precision - lower limits . . . . . . . . . . . 72
5.2. calibration cluster - 47Tuc . . . . . . . . 74
5.3. Target system - HD19994 . . . . . . . . . . . . . . . . 81
5.3.1. Relative astrometry . . . . . . . . . . . . . . . 82
5.3.2. Speckle Interferometry . . . . . . . . . . . . . 84
5.3.3. Radial velocity . . . . . . . . . . . . . . . . . . 86
5.3.4. Companion HD19994C . . . . . . . . . . . . . 88
5.3.5. Comparison with theoretical models . . . . . . 92
6. Summary and outlook 97
A. Calculation of ephemerides I
B. Calculation of atmospheric refraction index V
C. HD19994BC - Complex visibilities VII
D.HD19994C - Orbital solution IX
2E. HD19994C - Maps XV
F. Extended target list XIX
G. Acknowledgment XXXV
H. Ehrenwörtliche Erklärung XXXVII
iiList of Figures
1.1. Mass-orbit diagram of exoplanets . . . . . . . . . . . . 11
1.2. Propertiesofexoplanetsaroundsinglestarsandinstel-
lar multiple systems . . . . . . . . . . . . . . . . . . . 20
1.3. Statistical analysis of exoplanets around single stars
and in stellar multiple systems . . . . . . . . . . . . . 21
1.4. Properties of exoplanets in stellar multiple systems . . 23
1.5. Massandmultiplicitydependencyofexoplanetsinstel-
lar multiple systems . . . . . . . . . . . . . . . . . . . 26
2.1. Astrometric signal in a stellar binary . . . . . . . . . . 31
2.2. Reflex motion of the flux center around the common
center of mass . . . . . . . . . . . . . . . . . . . . . . 32
2.3. Differential parallaxe effect for a binary . . . . . . . . 34
2.4. Turbulences of earth’s atmosphere . . . . . . . . . . . 37
2.5. Differential chromatic refraction . . . . . . . . . . . . 42
2.6. Uncertainty of the differential refraction correction . . 44
2.7.ty of thetial aberration correction . . 48
3.1. Analysis strategy . . . . . . . . . . . . . . . . . . . . 60
3.2. Examples of complex visibilities . . . . . . . . . . . . 62
4.1. Old globular cluster 47Tuc . . . . . . . . . . . . . . . 64
4.2. Iterative calibration cycle . . . . . . . . . . . . . . . . 66
4.3. Field distortions on the NACOS13 camera . . . . . . 68
5.1. Chosen cluster stars of 47Tuc . . . . . . . . . . . . . 77
5.2. Measurements of the Master-Baseline . . . . . . . . . 77
5.3. Intrinsic instability of the chosen cluster stars . . . . . 79
5.4. Binary measurements of HD19994 . . . . . . . . . . . 82
iiiList of Figures
5.5. Visibilitiy and phase of HD19994BC for 2004 . . . . . 85
5.6. Astrometric measurements of HD19994A&BC . . . . 90
5.7. Specklets of HD19994B&C . . . . . . . . 90
5.8. Radial velocities of HD19994B&C . . . . . . . . . . . 91
5.9. Influence of the Br narrow band and the Ks broad
band filter on brightness ratio measurements. . . . . . 94
5.10.Theoretical evolutionary tracks for HD19994B&C . . 95
A.1. Orbit of a celestial body . . . . . . . . . . . . . . . . II
C.1. Complex visibilities of HD19994BC (2004 & 2006) . . VII
C.2. vis of HD19994BC (2007 - 2009) . . VIII
D.1. HD19994A&BC - orbital solution . . . . . . . . . . . X
D.2. HD19994B&C - orbital . . . . . . . . . . . . XI
D.3. HD19994B - astrometric reflex orbit . . . . . . . . . . XII
D.4. HD19994B&C - binary orbit . . . . . . . . . . . . . . XII
D.5. HD19994B&C - radial velocities . . . . . . . . . . . . XIII
2
E.1. Two dimensional maps . . . . . . . . . . . . . . . . XV
2
E.4. One maps . . . . . . . . . . . . . . . . XVIII
ivList of Tables
1.1. Exoplanets in closer binaries . . . . . . . . . . . . . . 15
1.2. in wider binaries . . . . . . . . . . . . . . 16
1.3. Exoplanets in stellar systems with more than two com-
ponents . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.4. Multiplicity of exoplanet host stars . . . . . . . . . . . 18
1.5. Critical semi-major axis of close stellar binaries . . . . 24
2.1. Astrometric jitter caused by stellar activity . . . . . . 35
2.2. Parameter uncertainties regarding the differential re-
fraction correction . . . . . . . . . . . . . . . . . . . . 43
2.3. Parameteruncertaintiesregardingthedifferentialaber-
ration correction . . . . . . . . . . . . . . . . . . . . . 47
2.4. Maximum gravitational light deflection . . . . . . . . 50
2.5. Stellar systems observed on the northern hemisphere . 54
2.6.ed on the southern . 55
5.1. Summary of remaining astrometric uncertainties . . . 73
5.2. Lower limits for astrometric measurement presicion . . 73
5.3. Measurements of the Master-Baseline . . . . . . . . . 78
5.4. Separation correction terms . . . . . . . . . . . . . . . 80
5.5. Position angle terms . . . . . . . . . . . . . 80
5.6. HD19994A&B separation measurements . . . . . . . 83
5.7. HD19994A&B position anglets . . . . . 84
5.8. HD19994B&C speckle measurements . . . . . . . . . 86
5.9. Radial velocities of HD19994B&C . . . . . . . . . . . 87
5.10.HD19994 corrected measurements . . . . . . . . . . . 89
5.11.Orbital elements of HD19994C . . . . . . . . . . . . . 91
5.12.Ks band magnitudes of the HD19994 system . . . . . 94
v