About 10,000 light-years from Earth, a dead star is devouring its living companion. The process creates a disk of gas that’s heated to millions of degrees, so it shines brightly. Some of the gas is fired back into space at almost the speed of light, adding to the fireworks. The system is so powerful that it’s classified as a microquasar – a smaller version of some of the brightest objects in the universe.
GRO J1655-40 consists of a black hole about six or seven times the mass of the Sun, plus a close companion star more than twice the Sun’s mass.
The black hole probably began as a star about 25 times the Sun’s mass. It evolved quickly, with its core collapsing to form the black hole. Its outer layers were blasted into space. Some of that material fell on the companion. Today, the black hole is pulling some of that gas away from the companion.
The same thing happens in the cores of many remote galaxies. Supermassive black holes create monster disks as they pull in gas, dust, and stars. Such a disk can shine billions of times brighter than the Sun – forming a quasar. GRO J1655-40 is a smaller version of that.
The system is in Scorpius, which crawls across the south on summer evenings. The microquasar is near where the scorpion’s body curves to form its tail.
Script by Damond Benningfield