V359 Cen : A New SU UMa star with P=0.081 d
On May 28, R. Stubbings reported an outburst of the dwarf nova V359 Cen.
The object had been regarded as a possible nova until the discovery of
an outburst in 1999 July by R. Stubbings. The last outburst was detected
by R. Stubbings on 2001 April 25 (vsnet-campaign-dn
2465). R. Santallo performed time-series photometry on May 31. His
observation detected a fully developed superhump signal with an amplitude
of 0.30 mag. The light curves indicated that the period was 0.08152(1)
d, which made V359 Cen as one of below-the-gap SU UMa-type systems with
the longest orbital periods (vsnet-campaign-dn
2491, 2492).
The object might belong to a sub-class including EF Peg and V725 Aql,
both of which show unusually infrequent outbursts for their superhump period
(vsnet-campaign-dn
2494). There may be even a hint of super-QPOs in the May 29 light
curve taken by P. Nelson. T. Kato reported that the superhump period decreased
at least during the early part of this superoutburst (vsnet-campaign-dn
2502, 2505).
T. Kato reported that the period analysis using data between May 31 and
June 3 indicated that the period shortening had stopped. The average superhump
period was calculated to be 0.08112 d. This strongly suggests that there
was a rapid evolution of superhumps around May 29. This interpretation
is strengthened by the likely presence of "super-QPOs" in the May 29 observation
(vsnet-campaign-dn
2508, 2509).
Combined data sets until June 5 showed a slight shortening of the superhump
period, although the entire set of data may not be expressed by a single
Pdot. There is also some suggestion of the beat phenomenon (vsnet-campaign-dn
2521). H. Yamaoka performed astrometry using images taken by R.
Santallo. He proposed identifications with a GSC-2.2 star of r=18.46 or
USNO-A2.0 star of R=17.7 (vsnet-campaign-dn
2522, 2524).
The light curve on June 6 by B. Monard showed the final stage of the superoutburst.
The object apparently entered the rapid fading stage, and was fading
at a rate of 0.50 mag/d. Superhumps were still prominent, without a strong
hint of late superhumps. After combining the data between May 31 and
June 6, a mean superhump period of 0.0809 d has been derived (vsnet-campaign-dn
2601). The superoutburst was terminated by a rapid decline started on
June 7 (vsnet-campaign-dn
2512, 2529,
2559).
Other articles:
vsnet-campaign-dn
2468, 2482,
2499
Link:
Preprint by T. Kato et al.
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-preprint/msg00082.html
VSNET special page for this object:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v359cen.html