Astronomers Discover Massive Hot Cloud Surrounding Baby Star

Scientists have made a new discovery. Using the ALMA telescope, they've found a baby star surrounding a large hot cloud about ten times larger than those found around typical solar-mass baby stars. The findings reveal a little bit more about baby stars and show an unusual example for researchers to study.

Baby stars are usually surrounded by natal gas and a dust cloud. This cloud is warmed up from its center, forming a hot molecular cloud, which is called a "hot core." Inside these hot cores, various molecules, originally trapped in the ice mantle around dust particles, are sublimated. These cores have temperatures of about -160 degrees Celsius, which is 100 degrees hotter than normal molecular clouds. In this case, though, the hot core discovered by ALMA shows that much more energy is emitted from the central baby star than typical solar-mass young stars. This could simply be down to the fact that there's a higher mass infall rate.

In this case, the researchers used ALMA to observe an IRDC named G34.43+00.24 MM3 (hereafter named MM3) in the constellation Aquila. The scientists found a young object from which the methanol molecular line is strongly emitted. In the end, the researchers found that the temperature of the methanol gas was around -140 degrees Celsius. This showed that MM3 harbored a baby star surrounded by a hot core.

"Thanks to the high sensitivity and spatial resolution, we need only a few hours to discover a previously unknown baby star," said Sakai, one of the researchers, in a news release. "This is an important step to understand the star formation process in a cluster forming region."

So why is the hot core in MM3 so large? In order to warm up the large volume of gas, the baby star should emit much more energy than typical ones. Protostars produce emission by converting the gravitational energy of infalling material to the thermal energy. The large size of the hot core in MM3 is probably due to the high mass infalling rate.

The findings reveal a little bit more about star formation. In addition, they show that ALMA can be used as a tool to help tell astronomers a little bit more about the universe.

The findings are published in The Astrophysical Journal.