One of the largest objects in the Kuiper Belt, a ring of icy bodies beyond Neptune, has finally gotten a name: Makemake, after a god in the culture of Easter Island.

But the International Astronomical Union, which made the decision, may have a far tougher time christening the next dwarf planet because of controversy over who discovered it.

Makemake, formerly known as 2005 FY9, is the first dwarf planet to receive a name since 2006, when its neighbour 2003 UB313 was named Eris after the Greek goddess of discord.

It joins Pluto and Eris as the only named 'plutoids', a term devised by the IAU to describe Pluto-like objects beyond Neptune.

The name Makemake belongs to the god who created humanity in the culture of Rapa Nui, or Easter Island. The name was suggested by a team led by Mike Brown of Caltech, which discovered the object around Easter time in 2005.

Not 'splashy'

Brown says he had trouble coming up with a suitable name to suggest, because the object – which is round and estimated to be more than half Pluto's size – doesn't have many "splashy" characteristics. "This one was hard. Often there's a name that sort of speaks to you, that directly relates to the object," Brown told New Scientist.

Although thinking of a name was hard, officially naming the object was easy, says astronomer Brian Marsden, secretary of the IAU Committee on Small Body Nomenclature, one of two IAU committees that are jointly responsible for naming dwarf planets. He says the name was submitted six months ago and was picked after relatively little discussion.

But the next plutoid on the slate for receiving a name, an oblong body called 2003 EL61, will likely prove much more contentious.

That's because the IAU has said it will try to give naming preference to a dwarf planet's discoverer. And two teams – Brown's and one led by Jose-Luis Ortiz of the Institute of Astrophysics of Andalusia in Granada, Spain – have laid claim to its discovery.

Observing logs

Ortiz announced the discovery on 28 July 2005, but server records showed that someone at his institution had accessed Brown's online observing logs of the object two days earlier.

Ortiz has said he found the logs after a graduate student showed him images of the object on 25 July. He said they had noticed a similar object described by Brown's team in a meeting abstract posted online a few days earlier and had searched the web for more information.

But Brown, who filed a complaint with the IAU in August 2005, questioned whether the Spanish team had actually identified 2003 EL61 before seeing his abstract and telescope log.

Both groups submitted names for 2003 EL61 about 18 months ago, but the IAU committees are just beginning to discuss names. "Who knows what the committees will accept," Marsden told New Scientist. "That's perhaps why we solved the problem of Makemake first. That was easy."

Comment subject
Comment
No HTML except lower case italic tags or lower case bold tags, please: <i> or <b>
Your name
Your email
	We need your email in case we need to contact you about the comment. We will not use it for any other purpose.

• For exclusive news and expert analysis every week subscribe to New Scientist Print Edition
• For what's in New Scientist magazine this week see contents
• Search all stories
• Contact us about this story
• Sign up for our free newsletter