Ten times bigger and fifteen times heavier than the Sun, X3 is the youngest star found in the Milky Way. A group of researchers from the Institute for Astrophysics at the University of Cologne made the discovery.
Journalists describe it as “a cosmic baby” because of its youth: it is “barely” tens of thousands of years old.
headed by german Florian Peissker, the team published the results this year in The AstrophysicalJournal.
The center of the Milky Way, known as Sagittarius A*, is a supermassive black hole that creates new luminous bodies. One of them is the X3 star.
The origin of the star X3
According to the researchers, X3 originated in an extensive cloud of dust that orbits the supermassive black hole.
“The properties of star formation are well defined and require environments characterized by sufficiently low temperature (below 20 K) and high gas density,” Peissker said, quoted by the Sci News portal.
“By contrast, the temperature of the gaseous dust filaments at the center of our Milky Way galaxy exceeds the gas temperature of 6000 K and the dust temperature of 250 K.”
According to Peissker, the dispersal velocity of all known objects near Sagittarius A* exceeds typical numerical values in star-forming regions by several magnitudes.
“Due to the presence of Sagittarius A*, tidal forces make it difficult for gas to accumulate, which is necessary for star formation,” the researcher stresses.
How did they come to discover the “cosmic baby”?
The astronomers used nearly three decades of data from four different telescopes to study a highly dynamic stellar object close to Sagittarius A*.
X3 probably belongs to a star cluster called IRS 13, which meets the conditions for star formation: a ring of gas and dust, cold and shielded from destructive radiation.
“With its large mass of around 10 solar masses, X3 is a giant among stars, and these giants evolve very quickly towards maturity,” said Michal Zajacek, an astronomer at Masaryk University and co-author of the research.
“We were lucky to detect the massive star in the middle of the comet-shaped circumstellar envelope. Subsequently, we identified key features associated with a young age, such as the compact circumstellar envelope that revolves around it.”