The 2003/2004 superoutburst of SDSS J013701.06-091234.9

We report on time-resolved photometry of the superoutburst of an SU UMa-type dwarf nova, SDSS J013701.06-091234.9, in 2003 December-2004 January. The obtained light curves definitely show superhumps with a period of 0.056686(12) d, which is one of the shortest superhump periods among those of SU UMa-type dwarf novae ever observed. Considering quiescent photometric studies, we estimated the fractional superhump excess to be 0.024. Spectroscopic observations by Szkody et al. (2003, AJ, 126, 1499) provided evidence for TiO bands despite the short orbital period, implying that the system has a luminous secondary star. We have drawn a color-color diagram of SU UMa-type dwarf novae in quiescence using 2MASS archives, revealing that the location of this star in the color-color diagram deviates from the general trend. The distance to the system was roughly estimated to be 300 ± 80 pc, using the empirical period-absolute magnitude relation and based on the proper motion. © 2006. Astronomical Society of Japan.