Using data from orbiting observatories and ground-based facilities, an international team of astronomers has discovered an outburst from a star thought to be in the earliest phase of its development.
The eruption, scientists
say, reveals a sudden accumulation of gas and dust by an exceptionally young protostar known as HOPS 383. Stars form within collapsing fragments of cold gas clouds. As the cloud contracts under its own gravity, its central region becomes denser and hotter.
By the end of this process, the collapsing fragment has transformed into a hot central protostar surrounded by a dusty disk roughly equal in mass, embedded in a dense envelope of gas and dust.
Astronomers call this a "Class 0" protostar.
"HOPS 383 is the first outburst we have ever seen from a 'Class 0' object and it appears to be the youngest protostellar eruption ever recorded," said William Fischer,
Nasa post-doctoral programme fellow at Nasa's Goddard Space Flight Center in Greenbelt, Maryland.
The "Class 0" phase is short-lived, lasting roughly 150,000 years, and is considered the earliest developmental stage for stars like the Sun.
A protostar has not yet developed the energy-generating capabilities of a Sun-like star, which fuses hydrogen into helium in its core. Instead, a protostar shines from the heat energy released by its contraction and by the accumulation of material from the disk of gas and dust surrounding it.
The disk may one day develop asteroids, comets and planets. The team continues to monitor HOPS 383 and has proposed new observations using Nasa's Stratospheric Observatory for Infrared Astronomy (SOFIA), the world's largest flying telescope.