Newest Dwarf Planet (and Plutoid): Makemake

by Nancy Atkinson on July 14, 2008


A Kuiper Belt Object discovered three years ago finally has a real name. It’s also officially been classified as a dwarf planet, and plutoid as well, by the International Astronomical Union (IAU). Formerly known as 2005 FY9, and also as 136472, (in addition to being unofficially called Easterbunny) the third largest known trans-Neptunian object is now Makemake. Pronouced like “maki-maki,” the object was named after the creator god from Easter Island mythology. Astronomer Mike Brown, one of the discoverers of Makemake, wrote in his blog that the IAU finally accepted his six-month old proposal to give the object a proper name. “Three years is a long time to have only a license plate number instead of a name,” wrote Brown, who appears to be pleased that the IAU accepted the name that he and his team suggested.

Makemake is now the fourth designated dwarf planet in the solar system, and the third plutoid, reclassified as such just a month after the category of plutoid was created.

Makemake is currently visually the second brightest Kuiper belt object after Pluto, and with an apparent magnitude of about 16.7, it’s bright enough to be visible using high-end amateur telescopes. It can be seen in the constellation Coma Berenices.

The Spitzer Space Telescope has studied Makemake with its infrared capabilities, which showed the presence of methane, possibly in Makemake’s atmosphere. Its size is not precisely known, but from the Spitzer data, combined with the similarities of spectrum with Pluto, astronomers estimate a size about about 1,500 km diameter. No satellites have been detected orbiting Makemake.

This object was discovered by Mike Brown, Chad Trujillo and David Rainowitz on March 31, 2005, just before Easter that year. They nicknamed it Easterbunny (which is easier to say than 2005 FY9 or 136472) and after tossing a few different names around, they finally came up with Makemake because of its Easter Island, (also known as Rapa Nui) connection.

Makemake is the creator of humanity and the god of fertility in the mythology of the South Pacific island of Rapa Nui. He was the chief god of the Tangata manu bird-man cult and was worshipped in the form of sea birds, which were his incarnation. His material symbol, a man with a bird’s head, can be found carved in petroglyphs on the island.

Original News Sources: Mike Brown’s Planets, Slashdot


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  • http://cosmos4u.blogspot.com Dan

    In the spirit of this cartoon I’ll refrain from continuing with this increasingly immature debate. Shall Laurie keep believing that the authority of the IAU is threatened by a few raging bullies. And may Jorge harbor his belief that it was Eris that led to the planet crisis – when it was in fact in 1999 when the planet definition issue first came up. With similar shouting as in 2006-8.

    Good night and good luck …

  • Laurel Kornfeld

    Jorge, what I meant when I said that the “clearing its neighborhood” requirement doesn’t work for our solar system is exactly what you said–the criterion is vague and subject to interpretation. It is also biased against planets further from their parent star, which have a far larger neighborhood to clear.

    Scott, what I actually said was, “None of the eight classical planets fully clears its orbit” (emphasis on the word “fully”). This goes back to the question of what criteria should we use to determine if a neighborhood is “cleared?” All of the eight classical planets have asteroids within their orbital fields, and Neptune does not “clear” its orbit of Pluto. So if this criterion is applied in a very literal sense, one could say none of the eight fully clear their orbits.

    Dan, the planet definition issue first came up not in 2006 or 1999, but in 1992, when the first Kuiper Belt Object was discovered. This is why Tombaugh, who died in 1997, was already aware of the controversy (although he always maintained that Pluto is a planet).

    ” A few raging bullies?” Are we seeing your true feelings about Dr. Stern and planetary scientists who disagree with you and with four percent of the IAU? It seems there is a bit of the pot calling the kettle black here, as it is that four percent of the IAU who are attempting to impose their definition on the rest of the world. It seems to me you’re the one who has started the name calling–”Pluto lovers,” “raging bullies,” accusations of “shouting,” etc. If you are incapable of conducting a mature debate with those of differing opinions, please do not blame others for your shortcomings.

  • http://lampadamagica.blogspot.com Jorge

    Scott, strictly speaking he’s right, you know?

    It’s all in the definition of “clearing”. If you define it as meaning that you can’t have anything nearby heavier than, say, 10 tons, then there’s not a single planet in the Solar System with a clear orbital path. If you define it as meaning that you can’t have more than the object’s worth of mass in its path, (and define the path as being a more or less wide volume of space, of course) then only the 4 gas giants and the 4 terrestrials make the cut. And which of these definitions is the correct one? Since where you put your limit is totally arbitrary, they both are.

    This said, I must say that I don’t like this argument. It’s useful to show how the current IAU definition is based on arbitrarily chosen values, but it’s not a good argument to suggest it doesn’t work. Because it does work, for the solar system as it currently stands, provided your definitions of “clearing” and “neighborhood” are carefully selected.

    The dynamic approach has other weaknesses, much more serious than that one, and I think it’s wrong to focus on something that can be easily rebated or explained while there are other arguments that dynamicists have a much harder time with. I spread a list of these throughout my comments.

  • poop schwartz

    its all wort poop

  • poop schwartz

    this is mad gay nobody should read it

  • poop schwartz

    im the only one makeing replies?

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