Enlarged Spleen Overview. The spleen is an important organ in the immune system. It is a bean shaped structure, located in the left upper portion of the abdominal cavity, under the diaphragm, tucked in between the 9th and 11th ribs, in the mid-back.
Chandra and NASA's Hubble Space Telescope later collected data from the event's afterglow, and together the observations led astronomers to conclude that the powerful explosions can result when a black hole and a neutron star collide, producing another black hole.
Most famously, black holes were predicted by Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass is more than about three times the mass of the Sun, the equations showed, the force of gravity overwhelms all other forces and produces a black hole.