Size of 2003 UB313 confirmed

[ajtribick]

2003 UB313 isn't quite as big as was previously thought, though still apparently (just) bigger than Pluto.

Downsizing the "Tenth Planet"

Edit: this is in error, see further down thread

[ElChristou]

BTW, is it or is it not officially the tenth planet of our system?

[Malenfant]

BTW, is it or is it not officially the tenth planet of our system?

It's not. Precisely for reasons like this, because the data needed further refinement.

[Ynjevi]

Yet another similarity with Pluto!

[ajtribick]

Then again, maybe reporters shouldn't try and scoop the discovery team...

Value given is 3000?±300 km.

[symaski62]

Code: Select all

"2003 UB313" "Sol" {

   Class "asteroid"
   Texture "asteroid.jpg"
   Radius  1500              # estimate
                InfoURL "http://www.astro.uni-bonn.de/~bertoldi/ub313/"
   EllipticalOrbit {
      Epoch        2453600.5    # 2005 Aug 18 00:00UT
      Period           557.148
      SemiMajorAxis     67.709       
      Eccentricity       0.4416
      Inclination       44.177     
      AscendingNode     35.875
      ArgOfPericenter  151.311     
      MeanAnomaly      197.538
      }
                Albedo 0.06
   RotationPeriod     48.0   # guess
}

[Captain-insane]

Sorry, but i can't class 2003 UB313 or Pluto as planet's, there just not big enough to fit my definition of planet's. Again sorry .

[Malenfant]

Sorry, but i can't class 2003 UB313 or Pluto as planet's, there just not big enough to fit my definition of planet's. Again sorry .

Why apologise? Ultimately it's the IAU definition of a planet that matters, not yours or mine or anyone else's...

[Captain-insane]

Mmmmm...yes.
Damn IAU .

[Planet X]

According to Michael brown's website, the general IAU assembly meeting to be held at Prague in August will be when the IAU will supposedly be making a decision on how to make a final decision! What the hell is that supposed to mean?

At any rate, the 3000 km size for 2003 UB313 greatly enhances the case for planethood, possibly the second member of a new class of planet. Rumor has it some members of the IAU want to create a new planetary class for bodies between roughly one sixth and half the size of Earth. Later!

J P

[buggs_moran]

Update on the IAU definition of a planet since Planet X's post. http://www.space.com/scienceastronomy/060608_planet_definition.html

"The International Astronomical Union (IAU) is expected to propose wording to delineate planets from other small, round objects at its 12-day General Assembly meeting in Prague this August. The proposal will be based on recommendations from a newly formed committee that includes experts outside the realm of astronomy tasked to break a deadlock in earlier committee discussions."

[Malenfant]

The proposal will be based on recommendations from a newly formed committee that includes experts outside the realm of astronomy tasked to break a deadlock in earlier committee discussions."

From outside the realm of astronomy? That's it, they've called in the astrologers, a tenth planet is really going to screw them up isn't it...

(though seriously I am wondering why anyone from outside the astronomical community even needed to be called in here... though reading the article I guess it makes some degree of sense if they're going to break the deadlock)

[buggs_moran]

(though seriously I am wondering why anyone from outside the astronomical community even needed to be called in here... though reading the article I guess it makes some degree of sense if they're going to break the deadlock)

They call in those people to give it a fancy name like Xena or Buffy . Oh no, wait, the astronomers actually did that... Perhaps they have some star trek fans there to show them how spherical classification is done in sci-fi (not bad ideas either)
http://en.wikipedia.org/wiki/Star_Trek_planet_classifications
http://www.ccdump.org/planetclass.html