Astronomers posit that the most massive and luminous stars in the Milky Way galaxy come to be within cool and dark clouds, but little is known about this process. Now, with the help of the ESO’s Atacama Large Millimeter/submillimeter Array, a team of astronomers has succeeded in taking a microwave prenatal scan to garner an in-depth view of a monster star that sits about 11,000 light years away from Earth in the Spitzer Dark Cloud 335.579-0.292.

Astronomers point out that there are two theories on how the most massive stars are formed. The first theory suggest that the parental dark cloud fragments, creating small cores that collapse on their own and eventually form stars. The second theory, which is a lot more exciting, suggests that the entire cloud begins to collapse inwards, with material moving rapidly towards the cloud’s center to form one or more massive stars there.

NASA’s Spitzer Space Telescope and the European Space Agency’s Herschel Space Observatory were the first to reveal the SDC’s vivid environment of dark, dense filaments of gas and dust. However, the ALMA was able to give astronomers an in-depth look at both the amount of dust and the motion of the gas moving around within the dark cloud.

Nicolas Peretto of CEA/AIM Paris-Saclay points out that the information from ALMA provided astronomers with the very first in-depth view of what is happening within the SDC. Through their efforts to examine how monster stars form and grow, the astronomers discovered one of the sources of these special stars: the largest protostellar core ever spotted in the Milky Way.

According to the international team of astronomers, this particular core has over 500 times the mass of our Sun moving around within it. Furthermore, information from ALMA showed that much more material is still flowing inwards and boosting the mass of the protostellar core. When this material collapses to form a star, astronomers believe that it will be up to 100 times as massive as the Sun.

Interestingly, only about one in ten thousand of all the stars in the Milky Way obtain that level of mass, Peretto notes.

Adding his two cents, Gary Fuller of the University of Manchester posits that finding one of these stars in its earliest stages is made more difficult by the fact that their birth is rapid and their childhood is short.

Observations from ALMA will help the team update their knowledge of star formation, while raising additional questions in the process.