Multiple stars across the H-R diagram : proceedings of the ESO Workshop held in Garching, Germany, 12-15 July 2005

316 Pages·2008·8.89 MB·English

by  S Hubrig, M Petr-Gotzens, A A Tokovinin, European Southern Observatory

S. Hubrig M. Petr-Gotzens A. Tokovinin (Eds.)
Multiple Stars Across
the H-R Diagram
Proceedings of the ESO Workshop
held in Garching, Germany,
12-15 July 2005
Volume Editors
Swetlana Hubrig Andrei Tokovinin
European Southern Observatory Inter-American Observatory
3107 Alonso de Cordova Cerro Tololo (CTIO )
Santiago, Vitacura La Serena
Chile Chile

Monika Petr-Gotzens
European Southern Observatory
Karl-Schwar schild-Str. 2
85748 Garching
Germany
Series Editor
Bruno Leibundgut
European Southern Observatory
Karl-Schwarzschild-Str. 2
85748 Garching
Germany
Library of Congress Control Number: 2007936287
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Preface
The ESO workshop “Multiple Stars across the H-R Diagram” was held in
Garching on 12–15, July 2005. The topics included observations of multiple
stars from ground and space, dynamical and stellar evolution in multiple
systems, effects of the environment on multiplicity, formation and early evo-
lution of multiple stars, and special components of multiple stars (chemically
peculiar stars, blue stragglers, brown dwarfs, etc.).
Stars show a marked tendency to be in systems of different multiplicity,
7
ranging from simple binaries and triples to globular clusters with N≈10 .
Modern observations give a frequency of binary and multiple stars in the
Galactic field of up to 70%, and between 5% and 20% of these systems are
at least triple. There is evidence that the degree of multiplicity increases
with primary mass. Many known multiple systems are too wide to have sig-
nificant physical interaction between their components. However, tidal and
N-body dynamical interactions are important even in relatively wide sys-
tems and probably lead to the shrinkage of inner orbits. This sets the stage
for spectacular evolutionary processes such as Roche-lobe overflow, merg-
ers, supernovae, formation of special components, etc. Only recently did we
realize that some of these processes require at least three stars.
The formation of multiple systems remains a difficult and challenging part
of astrophysics, although it has been addressed at the Workshop only briefly.
Instead, we concentrated on the subsequent stages, more precisely, on how
the components, evolution may affect multiple systems and whether there is
a difference in comparison to binary stars. The growing information on triple
and higher-multiplicity systems with a variety of characteristics has been used
to examine critically the assumptions underlying stellar evolutionary models.
The purpose of this meeting was to bring together teams interested in
studies of X-ray, UV, visual, near-IR and far-IR properties of stars of all
types which are members of multiple systems, and covering stars of high,
intermediate and low mass, thus combining specialists with complementary
expertise. The Workshop was well timed, since major developments hap-
pened in this field of research during recent years due to the availability of
large-aperture telescopes equipped with highly sophisticated instruments for
multi-wavelength observations, modern interferometers (VLTI, Keck interfer-
ometer, CHARA array, etc.) and new satellites such as Chandra, Fuse and
VI Preface
the Spitzer Space Telescope. The combination of results from satellites and
ground-based facilities resulted in vivid interaction between the experts of
all stellar type. The current state of observational and theoretical knowledge
has been reviewed, and priorities for future studies have been discussed, so
as to provide the necessary input for further progress in the understanding
of the genesis of multiple stars, their structure and their role for the study of
stellar evolution.
Altogether, 47 people from 16 countries attended this meeting, showing
that it was fulfilling a real need. Indeed, the reader will realize that significant
progress has been made in the last years, especially in the studies of dynamical
evolution in multiple stars, the effects of the environment on multiple system
parameters, stellar evolution within multiple stars, multiplicity of massive
stars, pre-Main-Sequence multiple systems of intermediate mass, multiplicity
of low-mass stars from embedded protostars to open clusters, and brown
dwarfs and planets in multiples. We look forward to the future progress which
will be presented in a few special sessions at the IAU Symposium 240 “Binary
Stars as Critical Tools and Tests in Contemporary Astrophysics” during the
XXVI-th IAU General Assembly in Prague this year.
We are grateful to all participants for stimulating presentations and dis-
cussions. We thank the local organizing committee chaired by Monika Petr-
Gotzens and the European Southern Observatory which fully sponsored this
conference.
Santiago and La Serena, Chile Swetlana Hubrig
May 2006 Andrei Tokovinin
Contents
Evolutionary Processes in Multiple Systems
P.P. Eggleton and L. Kisseleva-Eggleton . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Dynamics and Stability of Triple Stars
Seppo Mikkola . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Multiple Stars: Physics vs. Dynamics
R. Zhuchkov, V. Orlov and A. Rubinov . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Gliese 225.2: An Old (Stable?) Quadruplet
V. Orlov, A. Tokovinin, O. Kiyaeva, M. Sterzik, A. Rubinov and
R. Zhuchkov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Multiple Stars: Designation, Catalogues, Statistics
A. Tokovinin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Radial-velocity Studies of Certain Multiple Systems
R.F. Griffin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Spectral Disentangling Applied to Triple Systems: RV Crt
H. Hensberge, L.P.R. Vaz, K.B.V. Torres and T. Armond. . . . . . . . . . . . 47
Evidence for Rapid Variability in the Multiple System 68 u
Her
K. Uytterhoeven, P. Koubsk´y, P. Harmanec, J.H. Telting, S. Yang,
M.T. Richards and I. Ilyin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
DG Leo: A Triple System with a Surprising Variety of
Physical Phenomena
P. Lampens, Y. Fr´emat, H. Hensberge, V. Tamazian, J.A. Docobo and
Y. Balega . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
A Spectroscopic Study of HD 208905
,
Pavel Koubsk´y, Simone Daflon, Petr Hadrava, Katia Cunha ,
Jiˇr´ı Kuba´t, Dana Korˇca´kov´a, Petr Sˇkoda, Miroslav Sˇlechta,
Viktor Votruba, Verne V. Smith and Dimitri Bizyaev . . . . . . . . . . . . . . . . 67
The Suspected Binarity of the Nearby Flare Star Gl 424
V.S. Tamazian, J.A. Docobo and Y.Y. Balega . . . . . . . . . . . . . . . . . . . . . . 71
VIII Contents
The Ecology of Dense Star Clusters with Binaries
Simon F. Portegies Zwart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
The Formation of Multiple Stars
Eduardo J. Delgado-Donate and Cathie J. Clarke . . . . . . . . . . . . . . . . . . . 87
Population of Dynamically Formed Triples in Dense Stellar
Systems
Natalia Ivanova . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Interferometric Studies of Multiple Stars
Christian A. Hummel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Interferometric Orbits of New Hipparcos Binaries
I.I. Balega, Y.Y. Balega, K.-H. Hofmann, E.V. Malogolovets,
D. Schertl, Z.U. Shkhagosheva and G. Weigelt . . . . . . . . . . . . . . . . . . . . . . 113
New Facts about δ Velorum: Fewer but Larger Components
A. Kellerer, M.G. Petr-Gotzens, P. Kervella and V. Coud´e du Foresto . 119
Speckle Interferometry of Two Low-mass Triple Systems
in the Solar Neighbourhood
E.V. Malogolovets, Y.Y. Balega, K.-H. Hofmann, D.A. Rastegaev and
G. Weigelt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Tertiary Companions to Close Spectroscopic Binaries
A. Tokovinin, S. Thomas, M. Sterzik and S. Udry . . . . . . . . . . . . . . . . . . 129
Spectroscopic Subcomponents in Visual Double Stars:
The Most Probable Values of their Physical and Orbital
Parameters. Application to the System WDS 14404+2159
Jos´e A. Docobo and Manuel Andrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Multiple Stars in the Field
Brian D. Mason and William I. Hartkopf . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Multiplicity of Chemically Peculiar Stars
Swetlana Hubrig, Nancy Ageorges and Markus Sch¨oller . . . . . . . . . . . . . . 155
Multiplicity of Contact Binary Stars
T. Pribulla and S.M. Rucinski . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Extrasolar Planets in Double and Multiple Stellar Systems
A. Eggenberger, S. Udry, M. Mayor, G. Chauvin, B. Markus,
J.-L. Beuzit, A.-M. Lagrange, T. Mazeh, S. Zucker and D. S´egransan . 169
Homogeneous Comparison of Directly Detected Planet
Candidates: GQ Lup, 2M1207, AB Pic
Ralph Neuh¨auser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Contents IX
Searching for Planets Around Stars in Wide Binaries
Silvano Desidera, Raffaele Gratton, Riccardo Claudi, Mauro Barbieri,
Giovanni Bonannno, Mariangela Bonavita, Rosario Cosentino,
Michael Endl, Sara Lucatello, Aldo F. Martinez Fiorenzano, Francesco
Marzari and Salvo Scuderi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Multiplicity at the Very Low Mass End of the H-R Diagram
H. Bouy, E.L. Mart´ın, W. Brandner and J. Bouvier . . . . . . . . . . . . . . . . . 199
Spectroscopic Companions of Very Young Brown Dwarfs
Viki Joergens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
The Observed Multiplicity of Low-mass Stars: From
Embedded Protostars to Open Clusters
Gaspard Duchˆene and J´eroˆme Bouvier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
High-order Multiplicity of PMS Stars: Results from a
VLT/NACO Survey
S. Correia, H. Zinnecker, Th. Ratzka and M.F. Sterzik . . . . . . . . . . . . . . 233
Accretion onto Binary YSOs Through Gap from Their
Circum-binary Disk
Tomoyuki Hanawa, Yasuhiro Ochi and Koichi Ando . . . . . . . . . . . . . . . . . 239
The Nearest Pre-Main Sequence Multiple Stars
C.A. Grady . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
A Study of the Young Quadruple System AO Vel with a
ZAMS Eclipsing BpSi Primary and PMS Companions
J.F. Gonza´lez, S. Hubrig, N. Nesvacil and P. North . . . . . . . . . . . . . . . . 259
Multiplicity of Massive Stars
Hans Zinnecker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
1
The Triple System θ Orionis A in the Heart of the Orion
Trapezium Cluster
Monika G. Petr-Gotzens and Maria Massi . . . . . . . . . . . . . . . . . . . . . . . . . 281
The Primordial Binary Population in OB Associations
Thijs Kouwenhoven . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Multiplicity of Early-type Stars in the Field: Progress Report
N. Hu´elamo, G. Chauvin, C. Foellmi, M. Hartung, X. Haubois, V.
Ivanov, C. Melo, D. Nu¨rnberger and M. Sterzik . . . . . . . . . . . . . . . . . . . . . 295
Search for Low-mass Companions to X-ray Emitting A-type
Stars
B. Stelzer, G. Micela, N. Hu´elamo and M. Hu¨nsch . . . . . . . . . . . . . . . . . . 299
List of Participants
Andrade, Manuel Desidera, Silvano
Astronomical Observatory R.M. Osservatorio Astronomico di Padova
Aller (Spain) (Italy)
XII List of Participants
Hubrig, Swetlana Malogolovets, Eugene
ESO (Chile) Special Astrophysical Observatory
List of Participants XIII
Stelzer, Beate Tokovinin, Andrei
Osservatorio Astronomico di CTIO, La Serena (Chile)
Palermo (Italy)