SW UMa: Rare superoutburst in February - March

(2000 superoutburst light curve by the VSNET SW UMa collaboration team: Makoto Uemura, Taichi Kato, Brian Martin, Rudolf Novak, Denis Buczynski, Lew Cook, Elena Pavlenko, Sergei Shugarov, Nataly Katisheva, Gianluca Masi, Alessia Cassetti, Kohji Yoshikawa)

Early phase of the superoutburst

On February 11, T. Kinnunen and C. P. Jones reported an outburst of SW UMa at 14.2mag and 14.1mag, respectively (vsnet-alert 4185, 4186). P. Schmeer's observations were confirm the outburst. The last outburst (a supermaximum) was detected by G. Hanson on 1997 October 19.490 UT at mv= 11.1 (vsnet-alert 1269) (vsnet-alert 4188). During the April 1996 superoutburst, Nogami et al. reported the superhump period of 0.0582 d, small amplitude QPOs, 0.2mag anplitude super-QPOs (http://www.kusastro.kyoto-u.ac.jp/vsnet/DNe/superqpo.html), and clear increase of superhump period (vsnet-alert 4190). P. Schmeer reported further brightening to 11.0mag on February 12 (vsnet-alert 4191, 4197). M. Uemura and T. Kato reported it was brightening with 0.6 mag/d and no evidence of super-QPO, but 0.05mag modulations in February 13 light curve (vsnet-alert 4209). In the light curve on February 15 obtained at Kyoto, fully evolved superhump was still not seen (vsnet-alert 4228). In the next night (February 16), M. Uemura, T. Kato, and B. Martin observed the evolution of the superhump whose amplitude varied from about 0.1mag to 0.2mag within 10 hours (vsnet-alert 4244).

(Superhump light curve by the VSNET SW UMa collaboration team)

Late phase of the superoutburst

The object entered gradual decline phase followed by somewhat brightening from monotonous decline trend on February 26 when superhump had re-grown. (vsnet-alert 4289, vsnet-alert 4292). And then, it entered a rapid faiding phase on March 02 as reported by M. Uemura (the Kyoto team) (vsnet-alert 4321). During rapid decline on March 1 and 2, the Kyoto team detected flickering on the prominent superhumps (vsnet-alert 4331, 4338, 4346). G. Masi presented a light curve on March 3 at: http://www.eurolink.it/comets/swuma.gif (vsnet-alert 4337). The rapid decline stage was followed by again gradual fading slightly above its quiescent magnitude. During this phase (late) superhumps are gradually decaying (vsnet-alert 4362). E. Pavlenko (Crimea) and S. Shugarov (Moscow) have provided excellent post-superoutburst data which showed a short brigtening of by ~1 mag lasting at least 2 hours, in their time-series on March 14 (vsnet-alert 4426).

(Regrowth of superhumps on Feb. 27, observation by the Kyoto team and Rudolf Novak)

(Prominent superhumps and super-QPOs(??) seen during the final decline)

Light Curve and General Information of This Object