A short-lived, super-bright, high-energy flare, an X-ray nova has been detected by a NASA satellite. The X-ray nova is being released by a star system, which is 8,000 light-years away from Earth and is named V404 Cygni. The system, which is present in the constellation Cygnus, has a black hole in addition to a star that is somewhat smaller than the Sun.

As per reports, an X-ray nova sometimes is released from this black hole. However, since 1989, it was undiscovered until NASA’s Swift Gamma-ray Burst Explorer detected it on June 15.

According to Neil Gehrels, Swift's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland, “Relative to the lifetime of space observatories, these black hole eruptions are quite rare. So when we see one of them flare up, we try to throw everything we have at it, monitoring across the spectrum, from radio waves to gamma rays”.

Astronomers classify the V404 Cygni system as a low-mass X-ray binary. According to reports, in this system, a star, which is somewhat smaller than the Sun, orbits a black hole 10 times its mass in merely 6.5 days.

Tidal forces are generated by the close orbit and strong gravity of the black hole. These forces drag a stream of gas from its companion star that is nearly the size of the Sun. The gas approaches a storage disk around the black hole and increases temperature to millions of degrees and leads to production of a stable stream of X-rays, while falling inward.