  We present a detailed study of McNeil's nebula (V1647 Ori) in its ongoing
outburst phase starting from September 2008 to March 2013. Our 124 nights of
photometric observations were carried out in optical V, R, I and near-infrared
J, H, K bands, and 59 nights of medium resolution spectroscopic observations
were done in 5200 - 9000 Ang wavelength range. All observations were carried
out with 2-m Himalayan Chandra Telescope and 2-m IUCAA Girawali Telescope. Our
observations show that over last four and a half years, V1647 Ori and the
region C near Herbig-Haro object, HH 22A, have been undergoing a slow dimming
at a rate of ~0.04 mag/yr and ~0.05 mag/yr respectively in R-band, which is 6
times slower than the rate during similar stage of V1647 Ori in 2003 outburst.
We detected change in flux distribution over the reflection nebula implying
changes in circumstellar matter distribution between 2003 and 2008 outbursts.
Apart from steady wind of velocity ~350 km/s we detected two episodic magnetic
reconnection driven winds. Forbidden [O I] 6300 Ang and [Fe II] 7155 Ang lines
were also detected implying shock regions probably from jets. We tried to
explain the outburst timescales of V1647 Ori using the standard models of FUors
kind of outburst and found that pure thermal instability models like Bell & Lin
(1994) cannot explain the variations in timescales. In the framework of various
instability models we conclude that one possible reason for sudden ending of
2003 outburst in 2005 November was due to a low density region or gap in the
inner region (~ 1 AU) of the disc.
