The diamond- star, described in a paper published in The Astrophysical Journal, is one of the coldest white dwarfs researchers have discovered. In fact, it’s so cool and dim that it can’t even be seen in the overwhelming vastness of space. Even if we were able to get closer, experts still say we wouldn’t be able to see it.

But they were able to deduce the massive diamond’s presence by the way its gravity disturbs steady radio pulses coming from a spinning companion star.

“It’s a really remarkable object,” study leader David Kaplan, a professor at the University of Wisconsin-Milwaukee, said in a statement from the National Radio Astronomy Observatory (NRAO). “These things should be out there, but because they are so dim they are very hard to find.”

When talking about stellar objects, “cold” is a relative term; this white dwarf is still burning at 2,700 degrees Celsius (4,892 degrees Fahrenheit), but that’s 5,000 times cooler than the centre of our planet’s sun.

This isn’t the first time scientists have found a large space diamond. In 2012, researchers discovered a planet roughly the size of two Earths that was made primarily of diamond. This one, however, is pure cut—a gleaming crystallized white dwarf just sitting out there in space.