  We present a detailed study of the post-outburst phase of McNeil's nebula
(V1647 Ori) using optical B,V,R,I and NIR J,H,K photometric and low resolution
optical spectroscopic observations. The observations were carried out with the
HFOSC, NIRCAM, TIRCAM and NICMOS cameras on the 2m HCT and 1.2m PRL telescopes
during the period 2004 Feb-2005 Dec. The optical/NIR observations show a
general decline in brightness of the exciting source of McNeil's nebula (V1647
Ori). Our recent optical images show that V1647 Ori has faded by more than 3
mags since Feb 2004. The optical/NIR photometric data also show a significant
variation in the mags (Delta V = 0.78 mag, Delta R = 0.44 mag, Delta I = 0.21
mag, Delta J = 0.24 mag and Delta H = 0.20 mag) of V1647 Ori within a period of
one month, which is possibly undergoing a phase similar to eruptive variables,
like EXors or FUors. The optical spectra show a few features such as strong
Halpha emission with blue-shifted absorption and the CaII IR triplet (8498A,
8542A and 8662A) in emission. As compared to the period just after outburst,
there is a decrease in the depth and extent of the blue-shifted absorption
component, indicating a weakening in the powerful stellar wind. The presence of
the CaII IR triplet in emission confirms that V1647 Ori is a PMS star. The
long-term, post-outburst photometric observations of V1647 Ori suggest an EXor,
rather than an FUor event. An optical/IR comparison of the region surrounding
McNeil's nebula shows that the optical nebula is more widely and predominantly
extended to the north, whereas the IR nebula is relatively confined (dia ~ 60
arcsec), but definitely extended, to the south, too.
