Quasi-simultaneous two band optical variability of the blazars 1ES
  1959+650 and 1ES 2344+514
  We report the results of quasi-simultaneous two filter optical monitoring of
two high-energy peaked blazars, 1ES 1959+650 and 1ES 2344+514, to search for
microvariability and short-term variability (STV). We carried out optical
photometric monitoring of these sources in an alternating sequence of B and R
pass-bands, and have 24 and 19 nights of new data for these two sources,
respectively. No genuine microvariability (intra-night variability) was
detected in either of these sources. This non-detection of intra-night
variations is in agreement with the conclusions of previous studies that
high-energy peaked BL Lacs are intrinsically less variable than low-energy
peaked BL Lacs in the optical bands. We also report the results of STV studies
for these two sources between July 2009 and August 2010. Genuine STV is found
for the source 1ES 1959+650 but not for 1ES 2344+514. We briefly discuss
possible reasons for the difference between the intra-night variability
behaviour of high- and low-energy peaked blazars.
