UV Per : Rare superoutburst in January

(The object started a superoutburst in the end of 2000.) From the observation on 2000 December 25 at Kyoto, T. Kato reported the detection of growing superhumps whose amplitude grew from less than 0.1 mag to 0.15 mag, and relatively rapid fading (0.3 mag/d). The superhump period was somewhat longer than that obtained by other authors on earlier superoutbursts. This suggests that the superhump was in its unsteady phase. It was also striking to note such an early appearance of superhumps in such a short period system (vsnet-campaign 622). The Kyoto data on December 26 shows that UV Per had risen by ~0.5 mag compared to December 25 and fully grown superhumps with amplitudes nearly 0.4 mag were seen (vsnet-campaign 627). The Kyoto data on December 27 showed smooth superhumps with an amplitude of 0.25 mag, and the rising stopped, and the object was apparently at maximum (vsnet-campaign 632). The object steadily faded since December 28. Clear superhumps with an amplitude of 0.2 mag are present in the light curve on December 28 (vsnet-campaign 636). T. Kato reported the analysis of combined data with Kyoto and B. Martin's observations, the best superhump period is determined as 0.06661 d, w hich is slightly longer than the previously published period (vsnet-campaign 639). On December 31, the fading rate has become slower, and the object still showed prominent superhumps with an amplitude of 0.2 mag (vsnet-campaign 647). The analysis of the January 4 data of the Kyoto team confirmed the rapid fading suggested by visual observations. T. Kato commented that the duration of superoutburst plateau is relatively short in such a rarely outbursting SU UMa-type star (vsnet-campaign 656, 659). G. Masi reported on January 8 that the light curve during the rapid fading phase shows superhumps with a large amplitude of 0.5mag (vsnet-campaign 663, 664).

The Kyoto observation on January 10 (by Iwamatsu et al.) showed that UV Per apparently stopped fading from the superoutburst (vsnet-campaign 670). On January 12, R. Ishioka found a rebrightening (vsnet-campaign 675). T. Kato mentioned that the interval between the fading from the main superoutburst and the rebrightening is about 7 days, which is a typical value for SU UMa-type rebrightening (vsnet-campaign 676). T. Vanmunster also reported the rebrightening to 14.3mag on January 12 (vsnet-campaign 677). The Kyoto data on January 12 showed a rapid, smooth fading from the rebrightening. The rate of decline amounts to 1.7 mag/d, which is one of the fastest time-scales observed in UV Per. There is no evidence of large-amplitude superhumps (vsnet-campaign 679). J. Pietz confirmed the same trend from his own observation on January 12 (vsnet-campaign 683). The rapid fading continued on January 13 (vsnet-campaign 685). The Kyoto team (observer Uemura) obtained a continuous coverage of UV Per on January 14, in which the most remarkable feature is the presence of large-amplitude modulations (up to 0.5 mag) with a possible period of ~4 hours (vsnet-campaign 686). The fading speed then became gradual and returned to quiescence (vsnet-campaign 695).

Other related articles: vsnet-campaign-dn 371, 372, 375, 383, 393, 394, 395, vsnet-campaign 641, 642

Lightcurves presented by J. Pietz: http://home.t-online.de/home/Jochen.Pietz/uvper1.gif
VSNET collaborator's light curve presented by T. Kato: ftp://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/UV_Per/001229.gif

General Information on This Object