E. Pavlenko, V. Malanushenko, G. Tovmassian, S. Zharikov, T. Kato, N. Katysheva, M. Andreev, A. Baklanov, K. Antonyuk, N. Pit, A. Sosnovskij, S. Shugarov
SDSS J080434.20+510349.2 is the 13th dwarf nova containing a pulsating white
dwarf. Among the accreting pulsators that have experienced a dwarf novae
outburst, SDSS J0804 has the most dramatic history of events within a short
time scale: the 2006 outburst with 11 rebrightenings, series of December 2006 -
January 2007 mini-outbursts, the 2010 outburst with 6 rebrightenings. Over
2006-2011, SDSS J080434.20+510349.2 in addition to positive 0.060^d superhumps
during the outburst and 1-month post-outburst stage, 0.059005^d orbital humps
in quiescence, displayed a significant short-term variations with periods P1 =
12.6 min, P2 = 21.7 min, P3 = 14.1 min and P4 = 4.28 min. The 12.6-min
periodicity first appeared 7 months after the 2006 outburst and was the most
prominent one during the following \sim 900 days. It was identified as
non-radial pulsations of the white dwarf. The period of this pulsations varied
within a range of 36 s, and amplitude changed from 0.013m to 0.03m.
Simultaneously one could observe the 21.7-min and 14.3-min periodicities with a
much lower significance level. During the minioutbursts the 21.7-min
periodicity became the most powerful, the 12.6-min periodicity was less
powerful, and the 12.6-min periodicity had the lowest significance. After the
2011 outburst the most prominent short-term periodicity appeared \sim 7 months
after the outburst, but at 4.28 min. We identified that variability with
periods P2, P3 and P4 could be additional pulsation modes, however the relation
of P4 to white dwarf pulsation also can't be excluded.
View original:
http://arxiv.org/abs/1111.2339
No comments:
Post a Comment