A photometric study of SDSS J081256.85+191157.8: Detection of orbital and negative superhump periods

• We analyzed the light curve of SDSS J081256+191157.
• A period of 0.160151d±0.0000790.160151d±0.000079 was detected in the data.
• It is consistent with the previously proposed orbital period.
• A quasi-periodicity of 0.148159(86) day was discovered in all data.
• This period should be most probably negative superhump period.

The results obtained from unfiltered photometric CCD observations of SDSS J081256.85+191157.8 made during 3 nights in January 2012 are presented. A period of 0.160151d±0.0000790.160151d±0.000079 was detected in the data. This period is consistent with the previously proposed orbital period of PorbPorb = 0.160151(79) day. A quasi-periodicity of 0.148159(86) day was discovered in all data. This period is a negative superhump period. Therefore we suggest that SDSS J081256.85+191157.8 is classified as a negative superhump system. An improved orbital ephemeris is also determined: Tmin(HJD)=2455929.510163(364)+0.160046(46)∗ETmin(HJD)=2455929.510163(364)+0.160046(46)∗E.