It took multiple telescopes, but astronomers were able to identify a new white dwarf in the Aquarius constellation. White dwarfs are the dense end states of stars similar to our sun. At the end stage, the nuclear fuel is spent and the star collapses to roughly the size of Earth. What makes this one interesting is that its mass has crystallized to look like a diamond.
The White Dwarf is also old, clocking in at 11 billion years old or roughly the same age as the Milky Way Galaxy. The discovery was brought about by Dr. Jason Boyles when he was a graduate student at West Virginia University. He identified a millisecond pulsar in the location.
Further observations of the area discovered that the pulsar had a companion star, either a neutron star or a cool white dwarf. It took two years and the Green Bank Telescope to hone in on the location of the pulsar.
One area that has the team perplexed is given the mass and distance of the new white dwarf, it should have been visible with using optical or infrared telescopes. Regardless, the old star finally has a spot on our star plots. The diamond in the sky turned out to be a needle in haystack when searching for it.
The National Radio Astronomy Observatory has a full press release on the discovery, which you can read here.