Astronomers find an Earth-sized diamond orbiting a pulsar .

 

Binary systems are often problematic for astronomers, since they can present situations that confuse when you don’t know what you’re looking at. The odd gravitational conditions created by having two stars in close proximity can create orbits that bend and look like a figure-eight, or some much more random Spirograph pattern that never repeats. So, when pulsar PSR J2222-0137 was found some 900 light years from Earth, its data was at first confusing. Both planets and the light they reflect seemed to be slightly off — and it wasn’t until scientists imagined a second body in the system that their observations began to make sense.

This second body is invisible because it’s so dim, emitting or reflecting little enough light that astronomers can’t resolve its properties directly. However, the disturbances in light relative to expectations can tell astronomers a lot about what must be out there — the coolest, dimmest, most unique white dwarf star ever discovered. Based on its effects on the system, this star must be roughly equal to our own Sun in mass. Given that it seems to have cooled to just 3,000 degrees Celsius — thousands of times cooler than our Sun — it is also likely no larger than the Earth itself.

This paper argues that as this star cooled it would have slowly solidified into a hardened carbon matrix — and the most famous hardened carbon matrix of all is, of course, diamond. There will undoubtably be portions of the heavenly body that are clear and classically diamond-like, but its low luminescence and the unusual way it was made make it likely that the planet won’t be a sparkling space-gem. In reality it likely has more in common with the tip of a saw blade than the setting of an engagement ring, but an Earth-sized hunk of the hardest known natural material is still pretty amazing.

Notably, this star has still not been directly observed. Though the gravitational and other data about the system make its existence a virtual certainty, it is so small and dim that it’s still difficult to capture. Remember that we only started directly seeing alien planets a few years ago, since they only reflect light and are thus much more difficult to spy from across the universe. This diamond remnant of a star should provide a nice challenge to astronomers, at least for a while, but soon enough they’ll be out hunting for objects even odder than this one.