… The discovery has been made by an international research team, led by Professor Matthew Bailes of Swinburne University of Technology in Melbourne, Australia, and is reported in the journal Science. … For the newly discovered pulsar, known as PSR J1719-1438, the astronomers noticed that the arrival times of the pulses were systematically modulated. They concluded that this was due to the gravitational pull of a small companion planet, orbiting the pulsar in a binary system.
The pulsar and its planet are part of the Milky Way’s plane of stars and lie 4,000 light-years away in the constellation of Serpens (the Snake). The system is about an eighth of the way towards the Galactic Centre from the Earth. The modulations in the radio pulses tell astronomers a number of things about the planet. … the companion must be small, less than 60,000 km (that’s about five times the Earth’s diameter). The planet is so close to the pulsar that, if it were any bigger, it would be ripped apart by the pulsar’s gravity. But despite its small size, the planet has slightly more mass than Jupiter.
“This high density of the planet provides a clue to its origin”, said Professor Bailes.
The team thinks that the ‘diamond planet’ is all that remains of a once-massive star, most of whose matter was siphoned off towards the pulsar. …
“This remnant is likely to be largely carbon and oxygen, because a star made of lighter elements like hydrogen and helium would be too big to fit the measured orbiting times,” said Dr Michael Keith (CSIRO), one of the research team members.
The density means that this material is certain to be crystalline: that is, a large part of the star may be similar to a diamond. …
It would be great if we invented.a way to send a probe through a wormhole to anywhere we can visually see from earth. It would be nice to see this diamond planet up close.