Date Time Black hole in Milky Way more massive than at first thought An international team of renowned astrophysicists including researchers from FAU has gained new insights into Cygnus X1. The black hole and its companion star are further away from Earth and considerably more massive than previously thought. The project has also delivered new answers to the question of how black holes are formed. The findings have been published in the leading journal ‘Science’. The first indication of something unusual was detected in 1964: two Geiger counters on board a suborbital rocket launched from New Mexico registered a strong x-ray source in our Milky Way. Eight years later, the US astronomer Tom Bolton discovered that this x-ray source was circling the star HDE 226868, a blue giant. Bolton concluded that Cygnus X-1, the name given to the invisible source, must be a black hole. Later observations proved that this assumption was in fact correct. ‘Cygnus X-1 is the first black hole ever discovered in our Milky Way,’ explains Prof. Dr. Jörn Wilms, astrophysicist at the FAU University Observatory.