Near-Infrared Monitoring and Modelling of V1647 Ori in its On-going 2008-12 Outburst Phase

TL;DR

This study monitors V1647 Ori during its 2008-2012 outburst using near-infrared photometry and spectral line analysis, revealing brightness variations, extinction patterns, and physical changes in the star's environment.

Contribution

It provides detailed near-infrared observational data and spectral energy distribution modeling of V1647 Ori during its outburst and quiescent phases, highlighting physical differences.

Findings

V1647 Ori shows a slow fading trend in all bands during 2012.

Brightness variations observed in nearby Herbig-Haro object HH22.

Modeling indicates significant changes in the protostar's physical parameters between phases.

Abstract

We present results of Mt Abu JHK photometric and HI Brackett $\gamma$ line monitoring of the eruptive YSO V1647 Orionis (McNeil's Object) during the on-going outburst phase in 2008-2012. We discuss JHK colour patterns and extinction during the outburst and compare these with the previous outburst phase in 2004-05 and the intervening quiescent period of about 2 years. Commencing from early 2012, the object shows a slow fading out in all the bands. We report brightness variations in the nearby Herbig-Haro object HH22 possibly associated with those in V1647 Ori. We also present modelling of the spectral energy distributions of V1647 Ori during its recent outburst and quiescent phases. The physical parameters of the protostar and its circumstellar environment obtained from the modelling indicate marked differences in the two phases.