CP Dra : New SU UMa-type dwarf nova with a long orbital period

CP Dra was a poorly known dwarf novae whose sub-class has not been established. On February 23, C. P. Jones detected a rare, bright outburst of 14.3mag. Contrary to the last outburst on 2000 May 15, this outburst lasted much longer. The peak brightness of the new outburst surpasses that of the GCVS maximum (15.1) and other available records (vsnet-campaign 788). T. Vanmunster discovered superhumps with an amplitude of 0.3mag during this outburst. This finding revealed that CP Dra is an SU UMa-type object (vsnet-campaign 793).

CCD image during the outburst of CP DRa. The image was taken at the Kyoto University.

While the early phase observations showed relatively short superhump period of 0.0687 day (by T. Vanmunster; vsnet-campaign 793) and 0.078 day (by the Kyoto team; vsnet-campaign 794), T. Vanmunster and M. Uemura later reported 0.08473 day and 0.08491 day, respectively, using combined data sets (vsnet-campaign 803, vsnet-campaign-dn 555). M. Uemura also reported the object was 0.2mag brightening between February 24 (the first observation at Kyoto) and 25 (vsnet-campaign-dn 555). In the late phase of the outbust, the data taken by the VSNET collaboration team showed 0.08348 (5) day periodicity, which implies the decreasing of the superhump period. Their observation on March 6 revealed the outburst entered a rapid fading phase (vsnet-campaign-dn 577).

Other related articles: vsnet-campaign-dn 532, 533, 534, 529, 538, 539, 540, 542, 548, 549, 551, 559, 562, 565, vsnet-campaign 789, 791, 792, 798, 799, 800,

Light curve preseted by R. Novak : http://ada.astronomy.cz

General Information on This Object