Hatena::Groupkanatatmp

KANATA ObsLog

2010-08-05

[] Spectroscopy of WZ Sge type dwarf nova V592 Her : update

f:id:kanataobslog:20100805182716p:image

We update the spectra of V592 Her.

2010-08-02

[] Spectroscopy of WZ Sge type dwarf nova V592 Her : update

f:id:kanataobslog:20100803020043p:image

We update the spectra of V592 Her. The spectra suddenly become red. The absorption lines and at 8200A become slightly deep comparing to that obtained on Aug, 1.

2010-08-01

[] Spectroscopy of WZ Sge type dwarf nova V592 Her

f:id:kanataobslog:20100802002252p:image

We performed the spectroscopic observation of WZ Sge type dwarf nova V592 Her. The spectrum shows the absorptions of Balmer series. These absorptions seem to be broadened to bluer wavelength region. The absorption lines indicate that the disk become optically thick due to its radiations from the high temperature.

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.

2010-06-03

[] J2138+26: gradually fading

f:id:kanataobslog:20100603183051p:image:left

After the rapid fading stopped, the object is now gradually fading. The V-J color index is ~1.2, close to that observed in GW Lib just after its superoutburst. J2138+26 is now very red.