Rapid optical variability in blazar S5 0716+71 during 2010 March

We report rapid optical variability for the blazar S5 0716+71 during 2010 March 08-10 & 19-20 in the CCD observations made from Mt.Abu Infrared Observatory. The light curves are constructed for the duration longer than 3-hours each night, with very high temporal resolution(~ 45 seconds in R-band). During 2010 March 08 source smoothly decayed by about 0.15 mag in 2.88 hours, apart from a fast flicker lasting about 30 mins. S5 0716+71 brightened up during March 09 and 10 showing high activity while it was relatively faint (> 14 mag in R) albeit variable during March 19-20. During March 9 & 10, rapid flickers in the intensity modulate the long term intra-night (~ 3 hours) variation. The present observations suggest that the blazar S5 0716+71 showed night-to-night and intra-night variability at various time scales with 100% duty cycle for variation along with microvariability at significant levels. On night-to-night basis, the source exhibits mild bluer when brighter nature. The interaction of shocks with local inhomogeneities in the jet appears to cause intra-night variations while microvariations could be due to small scale perturbations intrinsic to the jet.