__________________
All words, phrases, definitions and theories provided in the above post are, unless otherwise stated, the property of Champion Munch © 2005.

Sign up to sue the Sun

Briefly:

The discovery date of the tenth planet released in July was incorrect. The correct discovery date is January 5, 2005.

In September, astronomers discovered a moon around the tenth planet. Ultimately, the moon's motion around the planet will reveal the planet's mass.

Methane ice has been discovered on the tenth planet. Methane ice also exists on Pluto.

The tenth planet's orbit around the Sun has been refined a bit. Its orbital period is 559 years, its mean distance from the Sun is 67.9 AU, its maximum distance is 97.5 AU, and its minimum distance is 38.2 AU (which it reaches in 2257). Thus, at its closest, the tenth planet is closer to the Sun than Pluto's mean distance from the Sun (39.5 AU).

According to a well-placed source, the IAU committee assigned with defining "planet" failed to do so.

Since the name depends on whether it's classified as a planet, there is still no name.

Crimson is happy to call both Pluto and the tenth planet planets, employing the common-sense definition that a planet of the Sun must a) go around the Sun and b) be at least as large as Pluto.

The object is still out there, has been found a moon, has not yet a name and will not for a little while. Pluto still is being called a planet, more by habit than anything else, clearly a trans-neptunian.

I won't reignite the old debate...

__________________
The impossible often has a kind of integrity which the merely improbable lacks.

__________________
All words, phrases, definitions and theories provided in the above post are, unless otherwise stated, the property of Champion Munch © 2005.

Sign up to sue the Sun

Welcome back.

The wheels of planetary nomenclature be turning slowly and it'll be a while before a consensus is reached. Right now I'm more interested in hearing about further observations using HST and Keck.

I suspect Pluto's planethood will be safe unless we discover a similar-sized object near or inside Pluto's orbit, which seems unlikely. Worst case, Pluto has the special status of being the innermost (major) TNO, and that may help it keep its current status as a planet.

Hubble imaged 2003 UB313 just a few days ago to determine its diameter. Earlier, Hubble searched satellites around it.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

__________________
All words, phrases, definitions and theories provided in the above post are, unless otherwise stated, the property of Champion Munch © 2005.

Sign up to sue the Sun

I wish that people who wrote stories about this topic would qualify the number of planets with "it hasn't been officially decided yet" instead of stating the number they believe it is, as if it is a fact.

I read two separate stories this weekend from science writers that gave different numbers. One was in the USA Weekend magazine that goes out in newspapers. I love to see this topic written about in the mainstream. But every non-science person who reads this story is going to walk away believing that UB313 is the 10th planet, because the writer called it one throughout.

This month's Discover Magazine has a feature story about discovering exoplanets, and the "Letter from Discover" has an introduction to all planets beyond our nine. This letter states flat out that there are at least 11 planets, including Sedna and Xena. Inaccurate on two accounts--they aren't officially planets, and the name isn't Xena!

I know I'm being picky, but I just would like the public to know the true story. I deal with the public on a daily basis, and they are confused because different writers tell different stories! And I'm sure that even if writers consistently added in the "not officially" qualifier, most public would still gloss over that and be confused. But at least it wouldn't be due to inaccurate reporting.

I'm also not arguing that these objects *aren't* planets. If the decision is made that they are, I will gladly teach about our newly discovered planets! But I won't calll them that unless/until the IAU does. Hurry up, guys and gals!

__________________
All words, phrases, definitions and theories provided in the above post are, unless otherwise stated, the property of Champion Munch © 2005.

Sign up to sue the Sun

Unfortunately no. You may search for the Hubble Daily Updates (the observations are listed there, but not by individual object names). I've seen them listed on Hubble observation logs, but I never remember to save the link or manage to find the page again.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

"Quotes" makes a perfectly acceptable qualifier, in my opinion!

Mike Brown has updated his page about 2003 UB313, including new size calculations. His team has determined that the planet is 2400 +/- 100 km across and reflects 86 +/- 7% of the light it receives.

http://www.gps.caltech.edu/~mbrown/planetlila

Proposed 10th Planet Shrinks Under Hubble's Gaze

__________________
Everything I need to know I learned through Googling.

From ToSeek's linked article
Is it possible to explain how one can measure to within 4% (+/- 60 miles out of 1490) when only a couple pixels light up?

thats foolish you cant learn everthing from google

The article is thin on details, but they used more than one image -- it said 2 were sufficient. If the error was +/- .06 pixels, 1.44 pixels to 1.56 pixels, they're at 4% for the diameter.

Dithering, Sampling and Image Reconstruction

__________________
0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...

By the time New Horizons reaches Pluto, UB313 will be down to the size of an unpopped popcorn kernel... Now if there was more heat it could at least pop!

And I notice he continues to call it a planet *shrugs*

__________________
The impossible often has a kind of integrity which the merely improbable lacks.

You'd be surprised.

__________________
Everything I need to know I learned through Googling.

Demote Pluto and Kill Xena

__________________
Everything I need to know I learned through Googling.

I like that idea. After all, Earth is a dwarf compaired with Jupiter.

__________________
I'm not a scientist, but I play one on the internet.
http://www.rrac.org

It works great - right up until somebody finds a KBO as big as Mars. It wouldn't be a terrestrial and it wouldn't be a dwarf . . .

As I've mentioned before, I just can't get that emotional over the subject. I just get a kick that we have a reason to have the debate. It isn't same old, same old anymore!

I think we will need a real planet classification system, not so much because of KBOs, but as better techniques find more and more exoplanets. Whatever we come up with now, it will change again as we learn more.

__________________
I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

When I was in college (late 60s-early 70s), one of my professors called Pluto the "incredible shrinking planet", because it got smaller every time measurement techniques improved.

__________________
Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

What's frustrating about those recent Hubble measurements of 2003 UB313 is that its point out how wrong earlier measurements were.

Based on heat, the Max Planck group in Bonn measured the radius at 3000km +-400km. That means a range of 2600km to 3400km, right? It's a broad range, but at least it's an apparent admission of the degree of uncertainty. But from that range, it is clearly much larger than Pluto and so it played right into all of the "10th planet" assertions.

Now the new measurements are 2400km +-100km, or 2300km to 2500km. That means that the new maximum diameter is smaller than the old minimum! Clearly, the error bars on the earlier measurement were way off. In fact, it is now possible that 2003 UB313 may be smaller than Pluto, which is currently measured at 2306km +-20km.

Personally, I don't care how big or small 2003 UB313 turns out to be. But I have to admit that I am a little peeved at the gross overestimation of its size (or the underestimation of the potential error) from the group in Bonn.

__________________
"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

My guess is that the Bonn group probably adequately estimated the +/- error (that is, the precision), but that their method is inaccurate. Hopefully, someone there is refining their methods.

Actually, after reading the details of their measurements, it seems that they set their confidence limits at just one standard deviation. This implies a 68% chance of the actual diameter being within the limits they defined.

This is what threw me off. I am used to seeing two deviations used to give a 95% confidence. Of course, that would mean that their measurement would be 3000km +-800km (not 400), so maybe they thought that an incredibly wide range (2200km to 3800km) would look too silly to report.

__________________
"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

That's a bit disturbing. If they really deviated from standard practice to make their data look more precise, they should be spanked.

I'm not suggesting that. Maybe using a 68% confidence is standard practice in the astronomical community. But most of the statistical work I do is carry with confidence limits set at 95%. I did assume that 95% was fairly standard, though.

__________________
"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

Well, perhaps a good reminder to everyone that estimating your systematic error is always the hardest part to do well.

The Bonn group responds:

Comment on the recent Hubble Space Telescope size measurement of 2003UB313

__________________
Everything I need to know I learned through Googling.