HOPS 383

HOPS 383 is a Class 0 protostar. It is the first Class 0 protostar discovered to have had an outburst, and as of 2020, the youngest protostar known to have had an outburst. The outburst, discovered by the Herschel Orion Protostar Survey (HOPS) team, was first reported in February 2015 in The Astrophysical Journal Letters.

Outburst
HOPS 383 had an outburst between 2004 and 2006 (a "dramatic mid-infrared brightening"); the increase in magnitude was detectable at the 24 μm (35 times increase) and 4.5 μm, and was also detectable at the submillimetre. After 6 years, observations showed no signs of fading.

X-Ray
The Chandra X-Ray Observatory detected an X-ray flare from HOPS 383 in December 2017. This was the first detection of X-rays from a Class 0 protostar that will evolve into a sun-like star. The flare lasted 3 hours and 20 minutes. It significantly impacted the previously-thought timeline for when such events occur in the evolution of a protostar. Furthermore, it has improved astronomers' understanding of the Sun's earlier evolutionary stages.