J/A+A/430/137 Close visual companions in Scorpius OB2 (Kouwenhoven+, 2005)
The primordial binary population. I. A near-infrared adaptive optics search for
close visual companions to A star members of Scorpius OB2.
Kouwenhoven M.B.N., Brown A.G.A., Zinnecker H., Kaper L.,
Portegies Zwart S.F.
<Astron. Astrophys., 430, 137-154 (2005)>
=2005A&A...430..137K 2005A&A...430..137K
ADC_Keywords: Stars, double and multiple ; Photometry, infrared
Keywords: binaries: visual - binaries: general - stars: formation -
associations: individual: Sco OB2
Abstract:
We present the results of a near-infrared adaptive optics survey with
the aim to detect close companions to Hipparcos members in the three
subgroups of the nearby OB association Sco OB2: Upper Scorpius (US),
Upper Centaurus Lupus (UCL) and Lower Centaurus Crux (LCC). We have
targeted 199 A-type and late B-type stars in the K_S band, and a
subset also in the J and H band. We find 151 stellar components other
than the target stars. A brightness criterion is used to separate
these components into 77 background stars and 74 candidate physical
companion stars. Out of these 74 candidate companions, 41 have not
been reported before (14 in US; 13 in UCL; 14 in LCC).
Description:
The observations were performed with the ADONIS/ SHARPII+ system n the
ESO 3.6 meter telescope at La Silla, Chile. Our observing campaign was
carried out in two periods: a period from May 31 to June 4, 2000, and
one from June 5 to 9, 2001. Table1 lists results from the ADONIS
adaptive optics survey among 199 Sco OB2 member stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 348 Results from the ADONIS adaptive optics survey
among 199 Sco OB2 member stars
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [HIP]
4- 8 I5 --- HIP Hipparcos number of target (primary) star (1)
12- 16 F5.2 mag Jmag ? J magnitude of the observed star
20- 24 F5.2 mag Hmag ? H magnitude of the observed star
28- 32 F5.2 mag Ksmag ? Ks magnitude of the observed star
34- 44 A11 --- SpType Primary (target) star MK spectral type
48- 52 F5.2 arcsec rho ? Angular separation between target and
observed stars
56- 61 F6.2 deg PA ? Position angle, measured from North to East,
between target and observed stars
63- 64 A2 --- status [pcnb ] Status of the observed star (2)
66- 68 A3 --- subg Subgroup of target (primary) star (3)
71- 72 A2 --- Rem [JH ] JH: observing conditions were not
photometric
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Note (1): The Hipparcos member stars HIP 77315 and HIP 77317 are a common
proper motion pair (see the Double Star Catalog, Cat. I/237). Here,
the two stars are treated as separate primaries and not as one system.
Note (2): Status is coded as follows:
p = primary/single, target star
c = companion
n = new
b = background
Note (3): Subgroups use the following abbreviations:
US = Upper Scorpius
LCC = Upper Centaurus Lupus
UCL = Lower Centaurus Crux
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Acknowledgements: M.B.N. Kouwenhoven, kouwenho(at)science.uva.nl
(End) Patricia Vannier [CDS] 03-Feb-2005