The Planet, the White Dwarf, and the Neutron Star . ... NASA , NOAO Explanation: A planet , a white dwarf , and a neutron star orbit each other in the giant globular star cluster M4 , some 5,600 light-years away. The most visible member of the trio is the white dwarf star, indicated above in an image from the Hubble Space Telescope , while the neutron star is detected at radio frequencies as a pulsar . ... In such a system, the planet is likely to be about 13 billion years old. ...