M4 Globular Cluster

This sparkling picture taken by the Hubble Space Telescope shows the center of globular cluster M4. The power of Hubble has resolved the cluster into a multitude of glowing orbs, each a colossal nuclear furnace. M4 is relatively close to us, lying 7,200 light-years distant, making it a prime object for study. It contains several tens of thousands of stars and is noteworthy in being home to many white dwarfs — the cores of ancient, dying stars whose outer layers have drifted away into space. In July 2003, Hubble helped make the astounding discovery of a planet called PSR B1620-26 b, 2.5 times the mass of Jupiter, which is located in this cluster. Its age is estimated to be around 13 billion years — almost three times as old as the solar system. It is also unusual in that it orbits a binary system of a white dwarf and a pulsar (a type of neutron star).