Dwarf Planet Number Five!

Image credit: compiled from NASA public images

I like it when a new dwarf planet gets added to the Official IAU List. I was pleased to welcome Makemake onto the list in July. Now, only two months later, comes a fifth dwarf planet: hello, Haumea.

Follow up:

Formerly 2003 EL₆₁, Haumea earns an actual name along with dwarf planet status. The namesake deity this time is a goddess of Hawaiian origin (similar to Makemake). The two moons that accompany this chilly ellipsoidal are Hi'iaka and Namaka, the daughters of Haumea.

Haumea is another plutoid, a world in the Kuiper Belt. It's roughly fifty times further from the Sun than Earth is (for comparison, Pluto is about 40 times the Earth-Sun distance). It isn't very icy, surprisingly, which would make it different from the other plutoids; it has a thin icy crust over a mostly rocky body. The discovery team thinks that much of its icy coating was knocked off by an impact, possibly forming its two daughter-moons.

As you can see from the graphic above, it's rather warped, more football-shaped ("ellipsoidal") than spherical. This actually is going to make me rephrase my usual simplification.
I often say, "one of the requirements to be a planet or dwarf planet is that it have enough gravitational pull to draw itself into a sphere". Well, Haumea's clearly not a sphere, so I'll have to fall back to the official Geek-speak term, hydrostatic equilibrium.

This is another of Mike Brown's planets; I'm rapidly coming to the conclusion that Dr. Brown means to find and get dwarf-listed all the major bodies of the Kuiper Belt. (Recall that his team also discovered Eris and Makemake.)

Unfortunately, as you can see from Dr. Brown's link, there's a bit of an ugly story that goes along with this one. Briefly, Dr. Brown's team had been watching and observing this object, gathering data before they decided to announce or publish a discovery. Another team (from an observatory in Spain) made the announcement before Dr. Brown's team did. However, it turns out that the Spanish team may have looked at web logs showing where Dr. Brown's team was observing, and "discovered" the planet in Dr. Brown's data rather than in their own observations. The IAU lists Dr. Brown's team as the discoverers of Haumea's moons, and adopted their suggested planetary name; however, they have not committed themselves by listing either team as the "discoverers" of Haumea itself.

Scientists are only human, and for some, the desire for recognition may sometimes outrun the best scientific practices. Scientists too often publish "a startling result" before they've done a really thorough job of checking and re-checking. Sometimes, this even leads to the embarrassment of having to withdraw an announcement or discovery paper. Why, then, do scientists rush ahead? Because they're afraid of someone else announcing the results first, and therefore getting credit and recognition for a key finding. (For scientists, as for journalists, it's called being "scooped".)

Myself, I think this does science a disservice. The competition for first announcement can get downright unhealthy at times, as Haumea's sordid story shows. This case verged unusually close to actual cheating, but even when it's just a case of a race to the finish line, it can have repercussions. For example, a scientist may announce results in the media which never pan out in the long run, leading the public to distrust new scientific findings.

This announcement, however, is the end result of years of research, and I'm pleased as punch to pass it on! What I said before about Makemake, though, is still true now: I expect many more dwarf planet discoveries yet to come.

Note: the graphic above is an improved version of the one first posted on Sep. 19.

Note 2: Originally, text above read: "The fact that the IAU lists Dr. Brown's team as the discoverers, and adopted their suggested planetary name, suggests what they think on the subject." Brown's team isn't listed for Haumea itself, so I've corrected this.