Multiple Stars across the H-R Diagram (eBook)

Preface 5
Contents 7
List of Participants 10
Evolutionary Processes in Multiple Systems 13
1 Introduction 13
2 Multiples with Two Periods Less than 30 Years 14
3 Multiples with Highly Inclined Orbits 16
4 Summary 21
5 Acknowledgments 21
References 21
Dynamics and Stability of Triple Stars 23
1 Introduction 23
2 Disruption of Triple Systems and Scattering off Binaries 24
3 Long Lasting Stability 26
4 Numerical Methods for Triple Stars 29
5 Conclusion 31
References 31
Multiple Stars: Physics vs. Dynamics 33
1 Introduction 33
2 Statistics of Binaries and Multiples 34
3 Stability of Low-hierarchy Multiples 40
4 Discussion and Conclusions 42
References 42
Gliese 225.2: An Old (Stable?) Quadruplet 43
1 Introduction 43
2 Observations 44
3 The Orbits of Subsystems 44
4 Discussion 47
References 47
Multiple Stars: Designation, Catalogues, Statistics 48
1 Designation of Multiple Stars 48
2 Multiple-Star Catalogues 49
3 Statistics of Multiple Stars 50
4 Conclusions 53
References 53
Radial-velocity Studies of Certain Multiple Systems 54
References 56
Spectral Disentangling Applied to Triple Systems: RV Crt* 57
1 Introduction 57
2 Data 58
3 Component Spectra 59
4 Fundamental Stellar Parameters 60
5 Future Work 62
Acknowledgments 62
References 62
Evidence for Rapid Variability in the Multiple System 68 u Her 63
1 The Project 68 u Her 63
2 The Binary System 64
3 Rapid Variability 68
Acknowledgments 68
References 68
DG Leo: A Triple System with a Surprising Variety of Physical Phenomena 69
1 Introduction 69
2 Astrophysical Relevance 70
3 New Orbital Solutions and Dynamical Mass 72
4 Conclusions 74
Acknowledgements 74
References 74
A Spectroscopic Study of HD 208905 76
1 Introduction 76
2 Spectroscopy 76
3 Orbital Solution 78
4 Acknowledgments 79
References 79
The Suspected Binarity of the Nearby Flare Star Gl 424 80
1 Introduction 80
2 Observations 81
3 Binarity and a Rough Estimate of the Orbital Period 81
References 83
The Ecology of Dense Star Clusters with Binaries 84
1 Introduction 84
2 Simulations 85
3 Evolution of the Binding Energies 87
Acknowledgments 93
References 95
The Formation of Multiple Stars 96
1 Introduction 96
2 Episode I: The Gas Menace 97
3 Episode II: Attack of the Turbulence 99
4 Episode III: Revenge of the Binaries 104
5 Conclusions 106
References 107
Population of Dynamically Formed Triples in Dense Stellar Systems 110
1 Introduction 110
2 Method and Assumptions 110
3 Numerical Results on Dynamically Formed Triples 111
Acknowledgments 115
References 115
Interferometric Studies of Multiple Stars 116
1 If you have been Thinking of Using LBI... 116
2 Modeling of Interferometric Observations of . Virginis 119
3 ...Now is a Good Time to do it 121
References 121
Interferometric Orbits of New Hipparcos Binaries 122
1 Introduction 122
2 Orbits and Masses 123
3 Conclusions 126
References 126
New Facts about d Velorum: Fewer but Larger Components 128
1 A Nearby (~ 24pc) Eclipsing Binary System 128
2 VLTI Observations of the Eclipsing Binary 128
3 Results and Discussion 129
4 Conclusions 130
References 131
Speckle Interferometry of Two Low-mass Triple Systems in the Solar Neighbourhood 133
1 Introduction 133
2 GJ 900 133
3 KUI 99=GJ 795 135
References 136
Tertiary Companions to Close Spectroscopic Binaries 137
1 The Goals and the Sample 137
2 Adaptive Optics Observations 138
3 Search of Companions in 2MASS 139
4 Parameters of Tertiary Companions 139
5 Discussion 142
References 142
Spectroscopic Subcomponents in Visual Double Stars: The Most Probable Values of their Physical and Orbital Parameters. Application to the System WDS 14404+ 2159 144
1 Methodology 144
2 Application to WDS 14404+2159 146
3 Remarks 146
References 147
Multiple Stars in the Field 148
1 It’s the WDS, not the WBS! 148
2 Orbits 150
3 Common Proper Motion 152
4 Common Parallax 153
5 Proximity 154
6 The Washington Multiplicity Catalog (WMC) 154
References 159
Multiplicity of Chemically Peculiar Stars 161
1 Introduction 161
2 Observations 163
3 Discussion 163
References 167
Multiplicity of Contact Binary Stars 168
1 Introduction 168
2 Detection techniques 169
3 Statistics and results 172
References 173
Extrasolar Planets in Double and Multiple Stellar Systems 174
1 Introduction 174
2 Searching for Short-Period Planets in Spectroscopic Binaries 176
3 Probing the Multiplicity Status of Nearby Stars with VLT/ NACO 181
4 Conclusion 184
References 185
Homogeneous Comparison of Directly Detected Planet Candidates: GQ Lup, 2M1207, AB Pic 188
1 Introduction: Direct Imaging of exo-planets 188
2 Observational Evidence: Three Candidates 188
3 Derived Parameters 189
4 Mass Determination by Model Tracks 191
5 Summary and Discussion on Planethood 194
References 195
Searching for Planets Around Stars in Wide Binaries 197
1 Scientific Motivations 197
2 The Sample 198
3 Abundance Analysis 198
4 Radial Velocities 199
References 202
Multiplicity at the Very Low Mass End of the H- R Diagram 203
1 Introduction 203
2 Multiplicity of Ultracool Dwarfs in the Field 204
3 Multiplicity of Ultracool Dwarfs in the Pleiades Open Cluster 206
4 Multiplicity of Ultracool Dwarfs in the Upper Scorpius OB Association 208
5 Ultracool Dwarfs in other Types of Multiple Systems 211
6 Discussion 211
References 212
Spectroscopic Companions of Very Young Brown Dwarfs 214
1 Introduction 214
2 Results of RV Survey in Cha I 215
3 Detection of RV Planets around BDs in Cha I Feasible 216
4 Is the BD Desert a Scalable Phenomenon? 217
5 Conclusions 218
References 219
The Observed Multiplicity of Low-mass Stars: From Embedded Protostars to Open Clusters 221
1 Introduction 221
2 Multiplicity in Young Open Clusters 224
3 Multiplicity among Embedded Protostars 226
4 Implications for the Star Formation Process 229
References 232
High-order Multiplicity of PMS Stars: Results from a VLT/ NACO Survey 235
1 Observation and Data Reduction 235
2 Results 235
3 CTTS vs WTTS Companion Statistics 239
References 240
Accretion onto Binary YSOs Through Gap from Their Circum- binary Disk 241
1 Introduction 241
2 Model and Method of Computation 242
3 Results 243
References 246
The Nearest Pre-Main Sequence Multiple Stars 247
1 Introduction 247
2 Finding the Binary and Multiple Systems Associated with the A Stars 248
3 HD 104237 249
4 HD 169142 251
5 Binarity and Multiplicity 254
6 Significance of the PMS Multiple Stars: 255
Acknowledgements 257
References 257
A Study of the Young Quadruple System AO Vel with a ZAMS Eclipsing BpSi Primary and PMS Companions 260
1 Observations and RV Measurements 260
2 Spectral Analysis 260
3 Orbital Analysis 261
4 Physical Parameters 262
5 Conclusions 263
References 263
Multiplicity of Massive Stars 265
1 The Origin of the Orion Trapezium system 265
2 Relevant Papers 267
Final Note 278
Acknowledgment 278
References 278
The Triple System .1 OrionisA in the Heart of the Orion Trapezium Cluster 281
1 Introduction 281
2 Review of Available Data and Facts of .1 OriA 282
3 The Possible Nature of .1 Ori A2 284
References 286
The Primordial Binary Population in OB Associations 289
1 Introduction 289
2 The Observed Binary Population 290
3 The True Binary Population 293
Acknowledgments 294
References 294
Multiplicity of Early-type Stars in the Field: Progress Report 295
1 Introduction 295
2 Sample Selection 295
3 Observations 296
4 Current Status 297
References 298
Search for Low-mass Companions to X-ray Emitting A- type Stars 299
1 The Mysterious X-ray Emission from A Stars 299
2 Search for New Counterparts 300
3 Assigning New Counterparts to the X-ray Sources 301
References 302