A glitter in the sky caught their eye, and astronomers have documented what they believe is the first tiny planet made of diamond some 4,000 light years away, according to a study published on Thursday.
The discovery of the small, fast-spinning gem world that has more mass than the gas giant Jupiter was made by an international team of researchers who published their findings in the journal Science.
The diamond planet was once a huge star that is now a white dwarf after it lost most of its matter to its companion pulsar, a small spinning star about 20 kilometres in diameter. A white dwarf is what remains after a star like the Sun exhausts most of its energy, while a pulsar is a neutron star with an intense magnetic field that sends off pulses of high radiation that appear almost like blinking lights.
The pulsar's crystalline companion is believed to be about 60,000km in diameter, or about five times the size of the Earth. It orbits the pulsar every two hours and 10 minutes.
"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 the researcher Michael Keith.
Astronomers detected the odd couple with the Parkes radio telescope of the Australian Commonwealth Scientific and Industrial Research Organization.
* Agence France-Presse