Illustration of the extrasolar planet orbiting the millisecond pulsar PSR J1719-1438. The pulsar gas a spin period of 5.8 milliseconds and is situated 4000 light-years form Earth in Serpens Cauda. Astronomers have found that the pulsar is accompanied by a companion, called the 'diamond planet'. It is similar in mass to Jupiter but less than half that planet's size. It is most likely not a planet but rather a carbon-rich white dwarf star, similar in appearance to a large diamond. This view shows the pulsar seen from the surface of its companion. A planet or moon is eclipsing the pulsar.