In a remarkable discovery made by NASA’s Chandra X-ray Observatory as well as NASA’s NuSTAR and CSIRO’s ATCA, the scientists have stumbled on to what can be termed as the rarest and tightest orbital dance involving an alleged black hole and a companion star.
The reason why it is considered as one of the rarest is that when such a pair involving a dying star (that would later become a black hole) and another star exists, the gravitational pull on the part of the dead star is so large that the companion star doesn’t usually last this long. Meaning, as soon as the black hole is formed, the matter from the companion star is sucked into itself by the black hole, and eventually, the companion star ceases to exist.
However, in this case of the binary system that has been named as the X9, located in the globular cluster 47 Tucanae which is about 14800 light years away from earth the companion star has been at the closest distance to the black hole ever observed by the scientific community. The findings have been detailed and would be published in the Monthly Notices of the Royal Astronomical Society under the title “The ultracompact nature of the black hole candidate X-ray binary 47 Tuc X9.”
NASA’s Chandra X-Ray telescope also revealed that the companion star in the binary system has an orbital period of about 28 minutes. More specifically speaking, the companion star in this binary system is a white dwarf, and the supposed black hole could be a neutron star according to a few astronomers. The fact whether a dying star that has run out of its nuclear fuel would become a black hole or not is dependent on the mass of the star, and the mathematical relation is given by the Chandrasekhar limit.