Issue |
Astron. Astrophys. Suppl. Ser.
Volume 130, Number 3, June II 1998
|
|
---|---|---|
Page(s) | 415 - 419 | |
DOI | https://doi.org/10.1051/aas:1998421 | |
Published online | 15 June 1998 |
Contribution à l'étude de la binarité des étoiles de type Am
I. HD 125273, binaire spectroscopique à raies doubles HD 125273, a double-lined spectroscopic binary
Laboratoire d'Astrophysique (UMR 5572), Observatoire Midi-Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
Received:
25
March
1997
Accepted:
17
December
1997
We present an observing program undertaken at Observatoire de Haute-Provence, for the
search and study of spectroscopic binaries among Am stars. HD 125273 was recognized as an
Am star some time ago (Olsen 1980; Abt 1984); observations, carried out with the
CORAVEL spectrovelocimeter, show that this star is a double-lined spectroscopic binary; its
orbital elements are as follows:
days;
JD;
;
;
km/s;
km/s;
km/s;
Gm;
Gm;
.
Strömgren photometry of the star (Olsen 1983) permits us to estimate the following mean
physical parameters for the components of the binary:
K; log
; Mv = 1.24;
,
and to specify the evolutionary status of the system.
Assuming the above mass for the components,
we found
and
. This system
is thus a detached one without possibility of eclipses. It is likely that the two components are
Am stars of very close characteristics.
The
values, determined
from the correlation dips given by CORAVEL, are near 11 km/s
for both components. We retain for this binary the hypothesis of rotation-revolution
synchronism, because it leads to a value of the radius of the stars in agreement both with the
above value and the results of a previous study by Kitamura &
Kondo (1978) of similar, but
eclipsing, systems. The ratio of the correlation dip areas indicates
a magnitude difference
mag. As expected in detached systems of main sequence stars, such as Am's, HD 125273
obeys the mass-luminosity law.
Key words: stars: individual: HD 125273; binaries: spectroscopic / stars: fundamental parameters
© European Southern Observatory (ESO), 1998