Issue |
Astron. Astrophys. Suppl. Ser.
Volume 122, Number 1, April I 1997
|
|
---|---|---|
Page(s) | 123 - 129 | |
DOI | https://doi.org/10.1051/aas:1997286 | |
Published online | 15 April 1997 |
TT Arietis: Photometric variability from 1985 to 1994
Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko Shosse Blvd., BG-1784 Sofia, Bulgaria
Send offprint request to: Z. Kraicheva
Received:
21
February
1996
Accepted:
31
May
1996
Results of photoelectric observations of
TT Ari during the 1985–1994 interval are presented.
Observations were carried out at the Rozhen and Belogradchik
observatories as part of our programme for the study of anti-dwarf novae.
The long-term light curve in the standard UBV system
is constructed and peculiarities of the long-term behaviour
of the star in this time interval are discussed. 21 moments of maxima
and 14 moments of minima are added to the list of known maxima and minima of
3.2-hour modulations. The period of 3.2-hour modulations during the
1987/1988, 1989/1990 and 1990/1991 seasons is determined. In our 29 observing
runs we searched for 20-min
quasi-periodic variations, which were detected in 25 of
them. Our results show that in 1989, the 20-min modulation mean period
reached a local maximum of 19.45 min and declined afterwards.
The mean brightness variability analysis during the aforementioned
seasons confirmed the
reliability of the period suspected by Semeniuk et al. (1987).
Key words: accretion, accretion disks / stars: TT Ari / stars: cataclysmic variables / X-ray: stars
© European Southern Observatory (ESO), 1997