A black hole in stealth mode

Astronomers observed a binary star system that contains a low-mass star and a black hole. The black hole pulls material from its companion star extremely slowly and therefore emits only a very small amount of X-rays. “It is so quiet that it is practically a stealth black hole”.

The most luminous supernova revised

Last June astronomers detected the brightest supernova that has ever been observed, known as ASASSN-15lh. The object had been classified as hydrogen-poor superluminous supernova fuelled by a magnetar, altough it is hotter and more luminous than any other hydrogen–poor supernova thus making the classification uncertain. Now scientists try to uncover the nature of this mysterious source using new observational data.