Second outburst phase of McNeil's nebula (V1647 Orionis)

Abstract

The FU Ori/EX Od phenomenon represents a rare and not yet fully understood phase of the early evolution of low mass stars. Therefore, the photometric and spectroscopic monitoring of the post-outburst phase of these objects is required to settle the class of eruptive variables to which they belong. V1647 Ori had gone into outburst phase in early 2004 (McNeil 2004) and faded considerably around late 2005 (Ojha et al. 2006). It underwent another strong outburst in 2008 (Itagaki et al. 2008, Ojha et al. 2008). Such observed properties are rarely seen in cases of very young low mass stars. Our long-term observations from Sep 2008 to Sep 2009 show that V1647 Ori has not yet faded back to the pre-outburst phase.