An article published in “The Astrophysical Journal Letters” describes a research on Cygnus X-3, a binary system consisting of a massive star slowly consumed by its companion, a black hole or a neutron star that is gas continuously taking gas away from it. A team of researchers used NASA’s Chandra X-ray Observatory and the Smithsonian’s Submillimeter Array (SMA) to detect the emissions generated from Cygnus X-3, reflected by a star-forming cloud.
The Cygnus X-3 system is about 24,000 light years away from Earth and over the years it’s been already observed with various telescopes. In 2003, a study using the Chandra space telescope identified a source of X rays very close to that binary system. In astronomical terms, the distance is extremely small and that made it difficult to study a source close to a much more powerful one.
Only in 2013 it was announced that the mysterious object was a cloud of gas and dust. It’s small in astronomical terms with a diameter of about 0.7 light years and was nicknamed “little friend” for its proximity to Cygnus X-3 and Because it showed the same variations with a period of 4.8 hours of the binary system in the emission of X-rays. The astronomers realized that the cloud reflected the X-rays from Cygnus X-3 like a mirror.
The mass of the cloud was estimated very roughly, between 2 and 24 solar masses but it was an indication that it was a Bok globule, a small and dense star-forming cloud. The SMA radio telescope was used to study little friend discovering the presence of carbon monoxide molecules: its presence is a marker of molecular gas, the fuel that feeds star formation. It was a confirmation of the fact that the cloud is a Bok globule.
Another discovery was the presence of small jets coming from little friend and directed outwards, which indicate the presence of a star that started forming within it. Because of the location of the star with respect to Earth, a jet is moving toward us while another is moving away from us.
The image that brings together X-ray and radio detections shows Cygnus X-3 at the center, where is the brightest white object, while little friend is the other white, smaller, object with the jet moving toward us in blue and the one moving away from us in red.
The scientists think that Cygnus X-3 originated in a region of the Milky Way where stars are still forming. The problem is that these regions are found in the galaxy arms while Cygnus X-3 is in another area. One possible explanation is that a supernova pushed it away at very high speeds. It’s another of the research that can continue on this small group that include a forming star, one in its main sequence and one that ended its life.
