  Monoceros R2 (Mon R2) is one of the closest large active star-forming
regions. This extremely young and partially embedded region provides an
excellent laboratory for studying star formation and the early evolution of
young stellar objects (YSOs). In this paper, we conduct an optical study of the
greater Mon R2 region. Beginning with 1690 previously identified candidate
YSOs, we used 496 sources with good proper motions and parallaxes from Gaia DR3
to determine the astrometric properties for likely members of Mon R2. We then
used both astrometric and photometric (isochronal and variability) criteria to
determine that 308 of these stars are highly probable members. Using the same
criteria, we considered a broad area search around Mon R2 in Gaia DR3, and
separated candidate members from field stars. In total, we selected 651 likely
new cluster members that had been missed in the previous x-ray and infrared
excess selection techniques used in the past to establish cluster membership.
Revised astrometric properties of the cluster were found using the combined
sample of ~959 highly probable member stars. For the literature plus new
candidate member list, optical light curves were compiled from the Zwicky
Transient Facility. For 470 identified variable sources, we attempted
classification based on the Flux Asymmetry (M) and Quasi-Periodicity (Q)
metrics. We find that Mon R2 is dominated by quasi-periodic symmetric
variables, with aperiodic sources also a significant population. A few tens of
large-amplitude variables are identified that may be of interest for further
study.
