  M31 is an ideal laboratory for observing and studying recurrent novae. To
date, there have been 18 recurrent nova discovered in M31, six of which have
recurrence periods less than nine years. M31N 2017-12a (AT2017jdm) is a
transient that was reported near the center of M31, with the time of outburst
estimated to be 2017 December 24.141 +/- 0.42 based on constraints from
previous data. Here we present the photometric observations of M31N 2017-12a,
which we confirm as a recurrence of M31N 2007-10b.
