HOPS 383 is a Class 0

protostar A protostar is a very young star that is still gathering mass from its parent molecular cloud. It is the earliest phase in the process of stellar evolution. For a low-mass star (i.e. that of the Sun or lower), it lasts about 500,000 years. The p ...

. 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 ''The Astrophysical Journal'' (''ApJ'') is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler. The journal discontinued its print edition and b ...

''.

Observations

Outburst

HOPS 383 had an outburst between 2004 and 2006 (a "dramatic mid-infrared brightening"); the increase in

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

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 The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...

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 The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot Plasma (physics), plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as ...

's earlier evolutionary stages.

References

{{Stars of Orion Orion (constellation) Protostars