2003 UB313 larger than Pluto!

[nacnud]

Distant world tops Pluto for size<font color="yellow"><br />By Jonathan Amos<br />BBC News science reporter<br /><br />An icy, rocky world found last year to be orbiting the Sun in the distant reaches of the Solar System really is bigger than Pluto, scientists say. New observations of the object, which goes by the designation 2003 UB313, show it to have a diameter of some 3,000km - about 700km more than Pluto. The measurement was undertaken by a German team using a Spanish telescope, and is reported in the journal Nature. It is likely to bolster claims for the body to be given planet status.<br /><br /><font color="white">Well this spices the argument over KBO's up a bit! <img src="/images/icons/smile.gif" /></font></font>

 

[krrr]

Why is it that CNN's coverage ("Measuring the heat radiation of UB313 at a wavelength of 1.2 mm,...") is much more informative than SDC's (blah, blah) or even the blurb at nature.com (blah, blah)?

 

[y_ask_y]

BS

 

[silylene old]

Nice, CNN hired a science reporter who can actually report and write science! I hope to see more of this writer.<br /><br />(My cynical side says that this reporter must be very new and has not yet completed the mandatory journalism indoctrination of writing to the 8th grade median reading level for Americans) <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[mikeemmert]

Thanks for the Nature link, krrr.<br /><br />The discoverer, Mike Brown, had an estimate based on the Hubble Observatory:<br /><br /><font color="yellow">" Brown has also been trying to measure the size of UB313 by using the Hubble Space Telescope. Although he released preliminary findings on 25 January at a public meeting at Foothill College in Los Altos Hill, California, suggesting that UB313 was just a few percent larger than Pluto, he now says that measurement is wrong. "It was an extremely preliminary estimate," he explains."<font color="white"> <br /><br />I will stick my neck out and say that I think it will be found to be a little closer to the mass of Triton. That's because it is the lost moon of Triton.<br /><br />Since 2003 UB313 has a moon, Brown's measurement should have included it's mass. I am very interested in that figure. I bet it will be close to 0.003581 Earth masses, which is the mass of Triton. We'll see.</font></font>

 

[alokmohan]

But its welcome to know KBO larger than pluto.There may be even more.But plutos historical significance remains same.

 

[mikeemmert]

<blockquote><font class="small">In reply to:</font><hr /><p>Then the board crashed and I lost entry,This time I am poor planet only.<p><hr /></p></p></blockquote>That's OK, I'm only an asteroid. I really don't think it matters that much because sometimes these posts take a while to write, so you wind up making fewer of them.<br /><br />By going to Mike Brown's website, I was able to link to the press release by the Max Planck Institute on the IR measurements. It's really interesting. Some excerpts:<br /><br /><font color="yellow">"UB313 is somewhat different from the normal Kuiper belt in that its orbit is highly excentric and 45 degrees inclined to the ecliptic plane of the planets and Kuiper Belt. It is likely that is originated in the Kuiper Belt and was deflected to its inclined orbit by Neptune. For more detailed information on the Kuiper belt, browse the web page by David Jewitt"<font color="white"><br /><br />Having felt that Xena (temporary shorthand for the clumsy 2003 UB313) originated as a binary with Triton and was ejected from a 1:1 resonance (Lagrange point L4 or L5, where formed, or a later "horseshoe" 1:1 resonance where it was perturbed) with Neptune, I spent many hours trying to get the ovserved inclination of 44 degrees to the ecliptic plane with GravitySimulations. I got a null result; this didn't happen in spite of the extra energy imparted by the loss of Triton's energy and subsequent gain of Xena's with respect to Neptune. However, I easily got aphelions of 97 AU, sometimes even more.<br /><br />Something else perturbed Xena into it's inclined orbit.<br /><br /><font color="yellow">"The intensity of radiation measured with MAMBO-2 at 1.2 mm wavelength is quite faint and the observations were therefore rather challenging. In the units astronomers use, the average flux measured in the 5.6 hours of on-sky</font></font></font>

 

[mikeemmert]

Thank you for your astute post.<blockquote><font class="small">In reply to:</font><hr /><p>The diameter measurement is suspect because it hinges on a questionable assumption.<p><hr /></p></p></blockquote>And then unlike many posters you go on to back up that assertion, which is refreshing.<blockquote><font class="small">In reply to:</font><hr /><p>That the distance from the sun controls the heat contained in UB313 is not valid if it has a significant source of internal heat.<p><hr /></p></p></blockquote>I would have a hard time trying to figure out what that source of heat might be. Radioactive decay can pretty much be eliminated unless it is nearly pure rock. However, 2003 EL61 is in fact mostly rock. But I do not believe that radioactive decay produced significant heat in this case. This is opinion, which is all we have at the moment.<blockquote><font class="small">In reply to:</font><hr /><p>It is also not valid if it has recently been significantly further or closer to the sun as compared to when the measurement was taken.<p><hr /></p></p></blockquote>Xena has a highly eccentric orbit, and objects hang around at aphelion, moving very slowly. Xena has had a couple of hundred years for it's temperature to stabilize. I would tend to discount this as a factor.<blockquote><font class="small">In reply to:</font><hr /><p>It also is not valid if the surface holds this variance in heat longer or shorter than we expect it to. That would be controled by the composition of the surface, which we cannot know.<p><hr /></p></p></blockquote>You might have seen this or something like it or figured it out yourself. A quote from that: "<font color="yellow">Earth-bound astronomers taking Pluto's temperature have confirmed suspicions that the planet is colder than it should be. It's thought that the planet’s lower temperature is the result of interactions between its icy surface and thin nitrogen atmosphere.<br /><br />Using the Submillimet</font>

 

[mikeemmert]

Hello David;<br /><br />Here is the discoverer's (Mike Brown's) webpage on 2003 UB313. Xena is currently at apheliion, I regret to inform you.<br /><br />Xena's closest approach to the Sun is 38 AU, farther than Neptune, so there is not as much heating in the first place.<br /><br />That fourth power of temperature for radiated heat means that it takes a long, long time for it to cool. Still, Xena is definitely larger than Pluto. The closer it is to Triton's size, the happier I am.

 

[bonzelite]

yes, and Xena will not be the last one found larger than Pluto. this is the beginning of the end of 9 planets.

 

[proplyd53]

If size were the only criteria for defining a planet, you might be right. Howsomever, constitution holds a more significant claim. We classify planets by asking if they are terrestrial or jovian. Objects in the Kupier Belt are neither. We'll probably continue to call Pluto a planet though because we've got three generations of habit to break with fixing that mistaken label.

 

[mikeemmert]

Thanks for your viewpoint, stevehw.<blockquote><font class="small">In reply to:</font><hr /><p>...often 10-20 billions kms. out from the sun at aphelion,...<p><hr /></p></p></blockquote>This brings up a question of the division of the solar system into "inner" solar sytem and "outer" solar system. I would propose a new classification there - inner Solar system, inside of Jupiter's orbit, the "Mesosolar system", from Jupiter's orbit out to the ~47 AU cut off of the Kuiper belt, a relatively recent discovery, and the "outer Solar system", which at this point has one major and one minor object; Sedna and Buffy.<br /><br />I think the largest objects of the Mesosolar system have been found. But the outer solar system beckons.<blockquote><font class="small">In reply to:</font><hr /><p>perhaps as many as 10-20, or so larger than Pluto.<p><hr /></p></p></blockquote>Hmm...I'm not in a postition to guess at this point. Some preliminary stuff I've done with GravitySimulator indicates at least one object of >10 Jupiter masses. In this I am indebted to mlorry, who provided additional evidence after I told him I didn't find the evidence about Nemesis presented by Raup and Sepkoski convincing. If I remember right, you posted early in that thread and also found the early evidence unconvincing.

 

[Philotas]

Well, you could just make a new classification for KBO planets.... <div class="Discussion_UserSignature"> </div>

 

[mikeemmert]

Indeed. Maybe the largest of the KBO's could be called planets to distinguish them. In that case, Ceres is a planet, too, as the largest asteroid.<br /><br />KBO's fall into separate categories anyway, cubewanos and plutinos. Under this scheme, a cubewano would have to be chosen to represent those objects. That would be 2005 FY9. "Easterbunny"...<br /><br />The Easterbunny doesn't exist. Santa (2003 EL61) was real, but his story is distorted beyond recognition. Xena was a fictional character portrayed by Lucy Lawless.<br /><br />I got a kind of a queasy feeling when I looked up "Lagrange objects" (with quotation marks) on Google. A bunch of Catholic sites popped up, so I peeked. The "objects" part of that was a verb, not a noun, like Mr. Lagrange was a lawyer objecting to a point of law (unknown if this Mr. Lagrange was the mathematician, in those days it was all Church anyway).<br /><br />The Catholic articles with Mr. Lagrange's objection concerned "Beelzebub", the Lord of the Flies, a Palestinian diety named so for the Jews of the day to insult the Arab's god. He was expropriated by Christians to represent the Lord of the Underworld (Satan somehow delegated this to Beelzebub) which explained the swarm of flies. I'd say Beelzebub existed, being carved out of a piece of stone. I still much prefer Xena. But Xena was never mentioned in any myths until late in the twentieth century, whereas Beelzebub was a popular god in Palestine.<br /><br />Mike Brown said he had to go outside the Roman god naming tradition.<br /><br />They ran out of Roman gods in the asteroid belt.

 

[Philotas]

Hmm.... Well, I want to call them all planets; but picking repesentatives for a given population, doesn`t sound to bad. <br /><br />But I think you`ve breeched the critical point already when you`ve done that, so you can just about promote `em all. <div class="Discussion_UserSignature"> </div>

 

[yanks1419]

<font color="red">I think the thought of bringing another planet into our databases would be an excellent idea.</font><font color="orange">It would liven up the 2006 spirit.</font><font color="yellow"> Icreated a post about this awhile ago, it was called "A new planet?."</font><font color="green"> I also think that as our technology goes and when the new James Webb Telescope goes into space, we will be getting new members added to our databases of planethood.</font>/safety_wrapper>