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ALMA “Ultrasound Scan” of the Birth of a Monster Star

Physical Sciences Division - Irfu


Astrophysicists from the CEA, CNRS and Bordeaux 1 and Paris-Diderot Universities, working on an international cooperation project, have identified the mechanism behind the formation of a star fifty to a hundred times the mass of the Sun, located 11,000 light-years away. The observations from ALMA have allowed the researchers to fathom the molecular cloud that is giving birth to this giant star. This research was published in Astronomy & Astrophysics on July 10.

Molecular clouds are cosmic regions, composed mainly of molecular hydrogen and dust, which are dense enough to form stars. There are two theories concerning the formation of massive stars. According to one, the molecular cloud first fragments to create several small gas cores, which then collapse on themselves to give birth to stars whose mass is proportional to the size of each fragment. The second theory is more dramatic: the entire cloud collapses inwards and becomes denser as material rushes towards the center to finally form a giant star.

The stellar progenitor observed at the center of the molecular cloud observed by ALMA is the most massive in the whole Milky Way (500 times the Sun’s mass and steadily growing).

Read the entire article on the CEA website.

For more information

  • Visit the ALMA (Atacama Large Millimeter/submillimeter Array) website.