Oldest known planet in globular cluster M4
author: Nasa/Noao/Aura/Nsf/Novapix
reference: a-agb61-21002
Image Size 300 DPI: 25 * 20 cm
Hubble Space Telescope image of stars in globular cluster M4. Marked is a white-dwarf star, which is orbited by the pulsar called PSR B1620-26; this system had been discovered by radio astronomers in 1988. Only the white dwarf is visible in this image. The system has a third companion, it has a mass 2.5 times larger than planet Jupiter, and is thus recognized as a planet.