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

Abstract 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 0.160151 d ± 0.000079 was detected in the data. This period is consistent with the previously proposed orbital period of P orb = 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: T min ( HJD ) = 2455929.510163 ( 364 ) + 0.160046 ( 46 ) ∗ E .