UV Per: Rare superoutburst on December
As reported by M. Simonsen on December 25 in
[vsnet-outburst 1233],
the SU UMa-type dwarf nova UV Per experienced one of its relatively
rare outbursts at 12.0mag. The most recent outbursts were in 1999 June
(mv=12.8, Poyner, normal outburst) and 1998 July superoutburst.
The outburst interval suggest that this outburst is a superoutburst
(vsnet-campaign 613,
614).
The Kyoto team performed four hours
time-series photometry on December 25, and confirmed the outburst
at about 12.2mag
(vsnet-campaign 615).
From the 6.5-hour observation on December 25, the Kyoto team
have been able to detect growing superhumps. The amplitude grew from
less than 0.1 mag to 0.15 mag. The other striking feature is the
superimposed relatively rapid fading (0.3 mag/d). The superhump period
determined from the run is 0.0678 d, which is substanstially longer
than that obtained by other authros on earlier superoutbursts. This
suggests that the superhump was still in its unsteady phase.
It is also striking to note such an early apperance of superhumps
in such a short period system.
(vsnet-campaign 622).
In the Kyoto data on December 26, we have apparently witnessed the most
important stage of the early development of superoutburst.
Fully grown superhumps, with amplitudes nearly 0.4 mag, were seen.
(vsnet-campaign 627).
The VSNET Collaboration team has received excellent data from B. Martin.
The analysis of combined data with Kyoto observations, the best superhump
period is determined as 0.06661 d, which is slightly longer than the
previously published period.
(vsnet-campaign 639).
(Data sets on UV Per from J. Pietz and K. Torii (NASDA, Japan))
(vsnet-campaign 642)