About 10,000 light years away from Earth, one of the soon to be largest stars in the galaxy is forming. Astronomers have gotten an unprecedented look at the birth.
The Atacama array telescope in Chile is the most powerful radio telescope in the world, and the site at which astronomers have been witnessing the birth of one of the most massive stars in the Milky Way. The forming star is a swirling cloud of compressing gas, the largest such “stellar womb” ever witnessed. The forming star is expected to be at least 500 times the mass of our Sun and many times brighter.
The astronomers have described in a research paper how the gasses in the cloud are being drawn into the forming stars by gravitational forces, along several dense strands. “The remarkable observations from ALMA [Atacama Relay] allowed us to get the first really in-depth look at what was going on within this cloud,” explains the paper’s lead author Dr Nicolas Peretto, from Cardiff University, “We wanted to see how monster stars form and grow, and we certainly achieved our aim. One of the sources we have found is an absolute giant — the largest protostellar core ever spotted in the Milky Way!”
Artist’s depiction of massive star formation.
“Even though we already believed that the region was a good candidate for being a massive star-forming cloud, we were not expecting to find such a massive embryonic star at its center,” continues Peretto, “This cloud is expected to form at least one star 100 times more massive than the Sun and up to a million times brighter. Only about one in 10,000 of all the stars in the Milky Way reach that kind of mass.”
There are many theories circulating about how massive stars form, but the research seems to indicate that the entire core of the gas cloud collapses inwards and rains towards the center, forming one or sometimes several massive stars. Such stars form both rarely and very rapidly, making observations like this one quite uncommon.
Luckily, the observations were made in unprecedented detail, utilizing the power of the telescope: “We managed to get these very detailed observations using only a fraction of ALMA’s ultimate potential. ALMA will definitely revolutionize our knowledge of star formation, solving some current problems, and certainly raising new ones.” said Peretto.