| Issue |
Astron. Astrophys. Suppl. Ser.
Volume 147, Number 2, December I 2000
|
|
|---|---|---|
| Page(s) | 243 - 249 | |
| DOI | https://doi.org/10.1051/aas:2000300 | |
| Published online | 15 December 2000 | |
Period changes in W UMa-type eclipsing binaries: DK Cygni, V401 Cygni, AD Phoenicis and Y Sextantis*
1
Astronomical Institute, Charles University Prague, CZ-180 00 Praha 8, V Holešovičkách 2, Czech Republic e-mail: wolf@mbox.cesnet.cz
2
Astronomical Institute, Academy of Sciences of Czech Republic, CZ-251 65 Ondřejov, Czech Republic
Send offprint request to: M. Wolf
Received:
21
July
2000
Accepted:
11
September
2000
We present a period analysis of the four well-known W UMa-type
eclipsing binaries
DK Cyg (
),
V401 Cyg (
),
AD Phe (
) and
Y Sex (
).
Several new times of minimum light, recorded photoelectrically,
have been gathered. Analysis of all available eclipse timings of the
DK Cygni and V401 Cygni has confirmed a significant increase in period
of 
and 
day cycle-1,
respectively. A simultaneous solution of the 
and R light
curves was computed for V401 Cyg using the Binary Maker 2.0 synthetic
lightcurve software. This solution indicates that V401 Cyg is in contact
with a filing factor of 46%.
The period of AD Phe seems to be constant.
Period changes of Y Sex could be explain by a light-time effect caused
by a third body in an eccentric orbit with a period of 58 years.
Key words: stars: : eclipsing / stars: : DK Cyg / stars: : V401 Cyg / stars: : AD Phe / stars: : Y Sex / stars: parameters
© European Southern Observatory (ESO), 2000