European astronomers, using the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile’s Atacama desert, have observed the birth of a massive star located about 10,000 light-years away from us.
An artist’s impression of the forming massive star (Manchester University)
“Observations reveal how matter is being dragged into the center of the huge gaseous cloud by the gravitational pull of the forming star – or stars – along a number of dense threads or filaments,” explained the astronomers, who report their findings in the journal Astronomy and Astrophysics.
Study lead author Dr Nicolas Peretto from Cardiff University said: “the remarkable observations from ALMA allowed us to get the first really in-depth look at what was going on within this cloud. 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!”
“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. 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.”
Different theories exist as to how these massive stars form but the team’s findings lend weight to the idea that the entire cloud core begins to collapse inwards, with material raining in towards the center to form one or more massive stars.
“Not only are these stars rare, but their births are extremely rapid and childhood short, so finding such a massive object so early in its evolution in our Galaxy is a spectacular result,” said co-author Prof Gary Fuller from the University of Manchester.
“Our observations reveal in superb detail the filamentary network of dust and gas flowing into the central compact region of the cloud and strongly support the theory of global collapse for the formation of massive stars.”
“Matter is drawn into the center of the cloud from all directions but the filaments are the regions around the star that contain the densest gas and dust and so these distinct patterns are generated,” added co-author Dr Ana Duarte-Cabral from the Université de Bordeaux.
“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,” Dr Peretto concluded.
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Bibliographic information: Peretto N et al. 2013. Global collapse of molecular clouds as a formation mechanism for the most massive stars. A&A, vol. 555, A112; doi: 10.1051/0004-6361/201321318
