KIC 11390659: new SU UMa-type dwarf nova with unusual characteristics

This object underwent an outburst on Oct. 15 (vsnet-alert 26986), which faded rapidly (vsnet-alert 26997). During this fading (precursor), Tamas Tordai and Vihorlat Observatory team recorded superhumps. On Oct. 19, Itoh-san also reported large-amplitude superhumps (nearly 1 mag) when the object was in a dip before the full superoutburst. This phenomenon was also reported by Tonny Vanmunster as "PECULIAR STAR", but after that VSNET network was disconnected.

Using the available data during the superoutburst plateau, the superhump period was 0.079679(8) d. The mean amplitude was large (0.23 mag). The plateau was short (Oct. 20-27) and the object started fading rapidly again. Following this, there was a rebrightening on Nov. 2-3 (apparently a normal outburst).

The short duration of the plateau was unusual for an SU UMa star with this period. Further observations are still wanted. It was a pity that VSNET was down during this event. Please send your observations (if there were) not reaching the VSNET addresses again (time-series CCD data to vsnet-campaign-report@ooruri.kusastro.kyoto-u.ac.jp as before), and please send new data as before.

The system problem was probably caused by an excessive amount of bounces in a certain provider, and announcement of full operation of VSNET and what should be done by the subscriber's side are expected to be given by D. Nogami, the manager.