Co-detection of the SU UMa-type nature of transient object
SDSS J163120.88+103134.0

The optical transient SDSS J163120.88+103134.0 was discovered by the Catalina Sky Survey as an optical transient object on May 5th, 2008.  

Following its outburst announcement, I started unfiltered CCD photometry of this variable star on May 5/6, 2008 at CBA Belgium Observatory, using a 0.35-m f/6.3 telescope and ST-7XME CCD camera. Independent from other observers (a/o Jochen Pietz and Pavol Dubovsky), I detected superhumps in this system, establishing the variable as a new member of the UGSU-type dwarf novae. 

I made follow-up observations on three successive nights (May 05/06, 06/07 and 07/08, 2008), on the basis of which I performed a period analysis, using the ANOVA method in Peranso. I added to my observations also a dataset obtained by Tom Krajci, CBA New Mexico. The resulting time series data contained 1096 observations and yielded a superhump period of 0.0639 +/- 0.0002 d. The superhump amplitude was ~0.36 mag. The phase diagram corresponding with the above listed superhump period is shown in fig. 3.

Fig. 1.
Observations of SDSS J163120.88+103134.0 by Tonny Vanmunster (pink, purple, brown sets) and Tom Krajci (gray set).

Fig. 2. Period window (ANOVA) showing dominant period at P = 0.0639 d

Fig. 3. Phase window corresponding to P = 0.0639 d





Copyright © 2008 - Tonny Vanmunster.