Scientists have observed a cloud of gas and dust giving birth to stars near Cygnus X-3, which could provide new insights on how stars form.
Images captured by NASA's Chandra X-ray Observatory and the Smithsonian's Submillimeter Array (SMA) showed that the stellar birth had been reflecting X-rays from the binary system Cygnus X-3, a source of X-rays produced by a system where a massive star is slowly being eaten by its companion black hole or neutron star.
"We nicknamed this object the 'Little Friend' because it is a faint source of X-rays next to a very bright source that showed similar X-ray variations," Michael McCollough of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts who led the most recent study about the star system, said in a statement.
In 2003, observations from Chandra's high-resolution X-ray vision showed a mysterious source of X-ray emission very near Cygnus X-3. In 2013, astronomers found that the source was a cloud of gas and dust. According to astronomers, the cloud, which is only about 0.7 light-years in diameter, was acting as a mirror and reflecting some of the X-rays generated by Cygnus X-3 towards earth.
The Chandra observations in 2013 suggested that the Little Friend had a mass between two and 24 times that of the sun, an indication that the cloud was a "Bok globule," a small dense cloud where baby stars could be born.
Moreover, data from SMA also revealed the presence of a jet or outflow within the Little Friend, which means that a star has started to form inside.
"Typically, astronomers study Bok globules by looking at the visible light they block or the radio emission they produce," Lia Corrales of the Massachusetts Institute of Technology and co-author of the study, said in the same statement. "With the Little Friend, we can examine this interstellar cocoon in a new way using X-rays - the first time we have ever been able to do this with a Bok globule."
According to the researchers, the proximity between Cygnus X-3 and Little Friend also give an opportunity to make precise distance measurements, which is difficult to do in astronomy.