New observations in the microwave range carried out with theALMA set(Atacama Large Millimeter / submillimeter Array) have provided astronomersthe best view ever of a gigantic star in the process of formation inside a dark cloudknown as the Spitzer Dark Cloud (SDC) 335.579-0.292. The embryonic star, located about 11,000 light-years away, greedily devours the material that falls into the cloud. It is believed that this cloud will give birtha very bright star, with more than 100 times the mass of the Sun. Only one in ten thousand of all the stars in the Milky Way reach such a mass.
There are two theories about the formation of the most massive stars. One of them suggests that the dark parent cloud fragments, creating several small nuclei that collapse on their own and eventually form stars. The other theory is more dramatic: the entire cloud begins to collapse inward, with material rushing toward the center of the cloud, forming one or more massive star beasts. A team led by Nicolas Peretto, from CEA / AIM Paris-Saclay (France) and the University of Cardiff (UK), concluded that ALMA was the perfect tool to discover what was really happening.
Thanks to observations made with NASA’s Spitzer Space Telescope and ESA’s Herschel Space Telescope, SDC335.579-0.292 revealed itself as a stunning dark environment of dense filaments of gas and dust. Now, the team has used ALMA’s unique sensitivity to discover thatthe core of the cloud is a true “star womb”which, with more than 500 times the mass of the Sun, is the largest of those found so far in the Milky Way, and which is still growing, as there is much more material still flowing inward and increasing the mass even more . Eventually this material will collapse, forming a young star more than 100 times the mass of our host star.
“These stars are not only rare, but their birth is extremely rapid and their childhood very short, so finding such a massive object at such an early stage in its evolution is a spectacular result,” says Gary Fuller, researcher at the University of Manchester (UK) and co-author of the study.
