Peculiar dwarf planet Haumea found to have rings around it

12 Oct 2017

An artist’s concept of Haumea and its moons, Hi’aka and Namaka. Image: NASA

The peculiar dwarf planet Haumea has just gotten more peculiar with the discovery of some faint rings.

One of the largest dwarf planets in our solar system, Haumea is found within the Kuiper belt band of asteroids. It shares some characteristics with Pluto, the largest-known dwarf planet in our region of space.

Earlier this year, Haumea passed between Earth and a distant star, revealing itself to astronomers like never before. With it came a surprising discovery, according to

The first sign that Haumea might have had rings was when researchers noticed that the light being emitted from the dwarf planet dipped just before and after it passed in front of the star designated URAT1 533-182543.

This suggested that something was obscuring it, most likely a series of rings, which was only confirmed after many months of follow-up research by a team led by José Luis Ortiz of Instituto de Astrofísica de Andalucía.

It is estimated that the rings could be as wide as 70km and encircle the planet at a distance of around 1,000km from its surface.

The discovery of the rings also suggests that Haumea might have been hit with something not long ago, at least in terms of space, possibly between 700m and 1bn years ago.

In fact, all of its strangeness might be linked with Haumea and its two moons – Hi’aka and Namaka – potentially originating from a larger Haumea that was struck by something in the Kuiper belt.

Dwarf planet status under threat

It wasn’t just rings that the team was looking out for, however, as researchers got an opportunity to analyse Haumea’s shape, which could jeopardise its status as a dwarf planet.

The most notable thing about Haumea’s shape is that it looks like it has more in common with an egg than something in space, being twice as long in one direction than the other, possibly caused by a very fast rotation.

The new measurements confirmed Haumea’s density – slightly lower than we thought – but its odd shape means its gravity is not strong enough to make itself round, which could see it miss out on the criteria set out for a cosmic body to be named a dwarf planet.

The study’s co-author, Pablo Santos Sanz, suggested that a debate will continue for some time but the loss of this status is likely.

Colm Gorey was a senior journalist with Silicon Republic