Hatena::Groupkanatatmp

KANATA ObsLog

2010-07-08

[] J2138+26: almost at quiescence

f:id:kanataobslog:20100708163850p:image

The WZ Sge-type dwarf nova, J2138+26, is now almost at quiescent level (CBET 2274). We found two noteworthy points in color variations: First, the V-J color remains constant in the last 10 days of the superoutburst. This suggests that the temperature of the outermost region of an accretion disk was almost constant at that period of time. Second, we could not see a very red phase just after the outburst, which was observed in GW Lib, a very similar source to J2138+26. In conjunction with the superhump evolution (e.g. vsnet-alert 11993), the lack of the very red phase implies that J2138+26 is not a very extreme WZ Sge-type object, but rather similar to ordinary SU UMa stars.