The Globular Cluster NGC 5286. II. Variable Stars
  We present the results of a search for variable stars in the globular cluster
NGC 5286, which has recently been suggested to be associated with the Canis
Major dwarf spheroidal galaxy. 57 variable stars were detected, only 19 of
which had previously been known. Among our detections one finds 52 RR Lyrae (22
RRc and 30 RRab), 4 LPV's, and 1 type II Cepheid of the BL Herculis type.
Periods are derived for all of the RR Lyrae as well as the Cepheid, and BV
light curves are provided for all the variables.
  The mean period of the RRab variables is <Pab> = 0.656 days, and the number
fraction of RRc stars is N(c)/N(RR) = 0.42, both consistent with an Oosterhoff
II (OoII) type -- thus making NGC 5286 one of the most metal-rich ([Fe/H] =
-1.67; Harris 1996) OoII globulars known to date. The minimum period of the
\RRab's, namely Pab,min = 0.513 d, while still consistent with an OoII
classification, falls towards the short end of the observed Pab,min
distribution for OoII globular clusters. As was recently found in the case of
the prototypical OoII globular cluster M15 (NGC 7078), the distribution of
stars in the Bailey diagram does not strictly conform to the previously
reported locus for OoII stars.
  We provide Fourier decomposition parameters for all of the RR Lyrae stars
detected in our survey, and discuss the physical parameters derived therefrom.
The values derived for the RRc's are not consistent with those typically found
for OoII clusters, which may be due to the cluster's relatively high
metallicity -- the latter being confirmed by our Fourier analysis of the
ab-type RR Lyrae light curves. We derive for the cluster a revised distance
modulus of (m-M)V = 16.04 mag. (ABRIDGED)
