| Issue |
Astron. Astrophys. Suppl. Ser.
Volume 142, Number 1, February II 2000
|
|
|---|---|---|
| Page(s) | 31 - 34 | |
| DOI | https://doi.org/10.1051/aas:2000133 | |
| Published online | 15 February 2000 | |
A period study of the W UMa type contact binary V 781 Tauri
Yunnan Observatory, Chinese Academy of Sciences, Kunming, Yunnan, China United Laboratory of Optical Astronomy, Chinese Academy of Sciences, China National Astronomical Observatories, Chinese Academy of Sciences, China e-mail: bily@public.km.yn.cn
Send offprint request to: Qingyao Liu
Received:
25
May
1999
Accepted:
2
November
1999
New times of minimum light determined from
the observations of the W UMa type contact binary
V 781 Tau are presented. According to these times of minima
and those collected from the references, the change in
the orbital period of the system is analyzed. The
result reveals that the orbital period of V 781 Tau
decreased continually from 1949 to 1998 and the change
rate in the period is 
. The
decrease in the period of the binary is explained by a model of
the contracting secondary component of the system.
The shrinking velocity of 
cm s-1 as
responsible for the change in the orbital period
of the system is obtained, which is in agreement with
the results shown in the study of the thermal
relaxation oscillation of contact binaries by Wang (1994).
Key words: stars: binaries: close / stars: binaries: general / stars: kinematics
© European Southern Observatory (ESO), 2000