Once the motion of the star is known, and the mass of the compact object has been determined, scientists can deduce whether the invisible component is a black hole or a neutron star: the upper limit f...Once the motion of the star is known, and the mass of the compact object has been determined, scientists can deduce whether the invisible component is a black hole or a neutron star: the upper limit for the mass of a neutron star is about three times the mass of the Sun.
Several decades ago advances in astronomical instruments opened new vistas on the Universe. Black holes popped out, sometimes glowing brightly in the darkness, other times remaining hidden except for ...Several decades ago advances in astronomical instruments opened new vistas on the Universe. Black holes popped out, sometimes glowing brightly in the darkness, other times remaining hidden except for their influence on visible neighbors. In this section we look at how black holes are detected and how they affect the Universe and its contents.