The specialists don't know the exact reasons behind the disappearance of the star. The most probable hypothesis is that the star has turned into a black hole.
The scientists, who observed the star, did not expect such a scenario. They believed that N6946-BH1 would explode as a supernova instead of disappearing out of sight.
"The typical view is that a star can form a black hole only after it goes supernova," a professor of astronomy at Ohio State University, Christopher Kochanek, was quoted by NASA website as saying.
"If a star can fall short of a supernova and still make a black hole that would help to explain why we don't see supernovae from the most massive stars," he added.
In 2015, astronomers found only a source of infrared radiation. They suspected that the star could have turned into a black hole, but the data have been confirmed only recently.
Assumptions suggest that about 30 percent of such stars may quietly collapse into black holes without supernova explosion.