HOPS 383: An Outbursting Class 0 Protostar in Orion

TL;DR

HOPS 383 is the first observed outbursting Class 0 protostar, showing significant mid-infrared brightening and variability, highlighting episodic accretion's role in early star formation.

Contribution

This paper reports the discovery of the first outbursting Class 0 protostar, providing new insights into early stellar evolution and episodic accretion processes.

Findings

Significant mid-infrared brightening between 2004 and 2006.

Persistent luminosity increase over six years without fading.

Detection of outburst in submillimeter and scattered light imaging.

Abstract

We report the dramatic mid-infrared brightening between 2004 and 2006 of HOPS 383, a deeply embedded protostar adjacent to NGC 1977 in Orion. By 2008, the source became a factor of 35 brighter at 24 microns with a brightness increase also apparent at 4.5 microns. The outburst is also detected in the submillimeter by comparing APEX/SABOCA to SCUBA data, and a scattered-light nebula appeared in NEWFIRM K_s imaging. The post-outburst spectral energy distribution indicates a Class 0 source with a dense envelope and a luminosity between 6 and 14 L_sun. Post-outburst time-series mid- and far-infrared photometry shows no long-term fading and variability at the 18% level between 2009 and 2012. HOPS 383 is the first outbursting Class 0 object discovered, pointing to the importance of episodic accretion at early stages in the star formation process. Its dramatic rise and lack of fading over a six-year period hint that it may be similar to FU Ori outbursts, although the luminosity appears to be significantly smaller than the canonical luminosities of such objects.