* Astronomy

The 2005 July Superoutburst of the Dwarf Nova 2QZ J021927.9-304545: the SU UMa Nature Confirmed
Authors: Akira Imada, Taichi Kato, L.A.G. Monard, Alon Retter, Alex Liu, Daisaku Nogami

Researchers report on time-resolved photometry of the 2005 July superoutburst of the dwarf nova, 2QZ J021927.9-304545. The resultant light curves showed conspicuous superhumps with a period of 0.081113(19) days, confirming the SU UMa nature of the object.
Although they missed the maximum phase of the outburst, the amplitude of the superoutburst well exceeded 5 magnitude. This value is slightly larger than that of typical SU UMa-type dwarf novae. The superhump period decreased as time elapsed, as can be seen in most SU UMa-type dwarf novae. Based on the archive of ASAS-3, the recurrence time of a superoutburst of the variable turned out to be about 400 days. This value is typical of well known SU UMa stars.
The distance to this system was roughly estimated as 370(+20, -60) pc using an empirical relation.

The entire light curve of the 2005 July superoutburst.
The abscissa and the ordinate denote HJD-2400000 and V magnitude, respectively. The open squares indicate the ASAS-3 photometry for which the typical error is within the size of the square. The duration of the plateau stage is at least 10 days, during which the object gradually fades at a rate of about 0.12 mag d-1.

Read more (PDF)