J/A+A/541/A34 Spectral types of stars in CoRoT fields (Sebastian+, 2012)
Early-type stars in the CoRoT-fields IRa01, LRa01, LRa02.
Sebastian D., Guenther E.W., Schaffenroth V., Gandolfi D., Geier S.,
Heber U., Deleuil M., Moutou C.
<Astron. Astrophys. 541, A34 (2012)>
=2012A&A...541A..34S 2012A&A...541A..34S
ADC_Keywords: Stars, early-type ; MK spectral classification
Keywords: techniques: spectroscopic - planets and satellites: formation -
surveys - stars: early-type - planets and satellites: detection
Abstract:
Observations of giant stars indicate that the frequency of giant
planets is much higher for intermediate-mass stars than for solar-like
stars. Up to now all known planets of giant stars orbit at relatively
far distances from their host stars. It is not known whether
intermediate-mass stars also had many close-in planets when they were
on the main sequence, which were then engulfed when the star became a
giant star. To understand the formation and evolution of planets it is
therefore important to find out whether main-sequence stars of
intermediate-mass have close-in planets or not.
A survey for transiting planets of intermediate-mass stars would be
ideal to solve this question, because the detection of transiting
planets is not affected by the rapid rotation of these stars. With
CoRoT it is possible to detect transiting planets around stars up to a
spectral type B4V. As a first step for an efficient survey we need to
identify intermediate-mass stars in the CoRoT-fields, which can then
be used as an input list.
To compile the input list we derived the spectral types of essentially
all O, B and A stars down to 14.5mag in the CoRoT fields IRa01,
LRa01, LRa02 taken with the multi-object spectrograph AAOmega. We
determined the spectral types by comparing the spectra with template
spectra from a library.
In total we identify 1856 A and B stars that have been observed with
CoRoT. Using multiple spectra of these stars, we find that the
accuracy of the resulting spectral classification is 1.61±0.14
sub-classes for A and B stars.
Given the number of planets that have been detected in these fields
amongst late-type stars, we estimate that there are one to four
transiting planets of intermediate-mass stars waiting to be
discovered. Our survey not only allows us to carry out a dedicated
planet search programme but is also essential for any types of studies
of the light curves of early-type stars in the CoRoT database. We also
show that it would be possible to extend the survey to all fields that
CoRoT has observed using photometrically determined spectral types.
Description:
Spectroscopic classification for 2950 O-, B-, and A-type stars in the
CoRoT-fields IRa01, LRa01, and LRa02. Stars are named by their
CoRoT-identifier and Coordinates are given. The visual magnitudes were
obtained with the Wide Field Camera filter-system of the Isaac Newton
Telescope at Roque de los Muchachos Observatory on La Palma and can be
converted into Landolt standards, as shown in Deleuil et al.
(2009AJ....138..649D 2009AJ....138..649D).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 2950 Spectral types for 2950 stars in the CoRoT-fields
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See also:
B/corot : CoRoT observation log Release 8 (CoRoT, 2012)
J/A+A/482/L17 : CoRoT space mission. I. (Barge+, 2008)
J/A+A/533/A4 : CoRoT photometry of three O-type stars (Blomme+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- CoRoT CoRoT-Number of the star
11 A1 --- n_CoRoT [*] * if star was observed by CoRoT
13- 21 F9.5 deg RAdeg Right Ascension J2000 (degrees)
23- 30 F8.5 deg DEdeg Declination J2000 (degrees)
32- 36 F5.2 mag Vmag V-band magnitude of the star
38- 44 A7 --- SpType MK spectral type of the star
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Acknowledgements:
We are grateful to the user support group of AAT for all their help
and assistance in preparing and carrying out the observations. We
particularly thank Rob Sharp, Fred Watson and Quentin Parker. The
authors thank DLR and the German BMBF for the support under grants 50
OW 0204, and 50 OW 0603 as well as DFG for the support of S. Geier
through grant HE1356/49-1.
Daniel Sebastian, sebastian(at)tls-tautenburg.de
(End) Daniel Sebastian [TLS, Tautenburg], Patricia Vannier [CDS] 12-Mar-2012