The results of 27 hours of time series photometry of SDSS 121209.31+013627.7
are presented. The binary period established from spectroscopy is confirmed and
refined to 0.061412 d (88.43 minutes). The photometric variations are dominated
by a brightening of about 16 mmag, lasting a little less than half a binary
cycle. The amplitude is approximately the same in V, R and white light. A
secondary small brightness increase during each cycle may also be present. We
speculate that SDSS 121209.31+013627.7 may be a polar in a low state.Comment: Accepted for publication in MNRA