Issue |
A&A
Volume 371, Number 3, June I 2001
|
|
---|---|---|
Page(s) | 1035 - 1047 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361:20010456 | |
Published online | 15 June 2001 |
Line-profile variations of the double-lined spectroscopic binary
Scorpii*
1
Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 B, 3001 Leuven, Belgium
2
Netherlands Organisation for Scientific Research, Isaac Newton Group of Telescopes, Apartado 321, 38700 Santa Cruz de La Palma, Spain
3
Astronomical Institute Anton Pannekoek, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
Corresponding author: K. Uytterhoeven, katrien.uytterhoeven@ster.kuleuven.ac.be
Received:
9
February
2001
Accepted:
22
March
2001
We present a total time series of high signal-to-noise,
high-resolution spectra of the SiIII ,
and
Ålines of the fast-rotating, spectroscopic binary and
β Cephei star κ Scorpii. Among this data set is a sample of 422
spectra of intensive monitoring during eight subsequent nights in July 1997. We
find variability of the line profiles on two time-scales: a variation of several
months as a result of the orbital motion and rapid variations of a few hours,
which are explained in terms of non-radial pulsation modes. From the total
dataset, covering a time span of 9 years, we derive for the first time the
orbital parameters of κ Scorpii and find an orbital period of 195 days.
The complex patterns on the grayscale representations of the residual SiIII
Åprofiles with respect to the average profile point
towards more than one (non-axisymmetric) pulsation mode. A frequency analysis
of the three normalised velocity moments confirms the main period of 4.80 hours
and the second period of 4.93 hours, which were previously derived from
photometric data. We attempt an identification of the pulsation modes by means
of the moment method and line-profile fitting and find that κ Scorpii
pulsates in a main prograde sectoral mode of degree 1 or 2 and in an additional
tesseral mode for which
,
are the most likely wavenumbers. In
the variations of the line profiles we find indications for the presence of
additional pulsation modes.
Key words: stars: binaries: spectroscopic / stars : oscillations / line: profiles / stars: individual: κ Scorpii
© ESO, 2001
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