A Puffed-Up Extrasolar Planet

Maggie McKee writes, "New Scientist Space reports astronomers have found a planet less dense than a wine cork and 38% larger than Jupiter. It circles a star about 450 light years from Earth. A similarly bloated planet has been found before (HD 209458b), so these puffed-up planets may be quite common. But no one knows how they got so swollen. One possibility is 'that some poorly understood mechanism has separated hydrogen and helium in each planet.'"

Bloated?

[daeg]

Maybe it's just their time of the month. Better keep your distance.

Re:

[AstrumPreliator]

Apparently the person who modded the parent as "Offtopic" was also being visited by Aunt Flow.

it's like a piece of candy

[Alien54]

with a chewy center, not a hard center inside.

probably not much of a rocky core

Actually....

[otis wildflower]

.... It's more like Kodak film.

Astronomers...

[/ASCII]

I love astronomy. In what other science does discovering two instances of the same thing make something potentially 'common'?

Reminds me of an old joke. An astronomer, a physisist and a mathematician are traveling on a train through Scotland. Through the window of the train they notice a black sheep.

"Aha," shouts the astronomer. "In Scotland, all sheep are black."

"Nonono, " says the physist. "We only know that there are black sheep in Scotland, not that all scottish sheep are black."

The matematician looks furiously at the other two and almost screams "In Scotland there is at least one sheep with at least on black side!"

Re:Astronomers...

[gEvil (beta)]

In what other science does discovering two instances of the same thing make something potentially 'common'?

When you consider that they've only observed an infinitesimally small portion of the universe, seeing two of the same thing suggests that there's a good chance there are more of them.

Re:Astronomers...

[/ASCII]

Nope. If you take a small number of samples from a very large and diverse population, the odds are actually very high that several of the very uncommon results (e.g. planet types) will be highly overrepresented. It's a variation on "there are so many extremely unlikely things which can happen that it's extremely likely that a few of them will happen."

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[ceoyoyo]

Certainly, if you take ten samples and you find one of something then it's very likely it's actual rate of occurrence is less than 1/10.

But if you find TWO, it is much more likely that the rate is actually in the ballpark indicated by your sample.

Re:

[cswiger2005]

Certainly, if you take ten samples and you find one of something then it's very likely it's actual rate of occurrence is less than 1/10.

I'm curious to see your reasoning for this. If you know that your sampling is not representative of the population, or you have a reason to suspect a bias which makes it more likely that you are finding instances of the "something" than if you had a lot more samples available, sure, I'd agree with your reasoning.

Re:

[ceoyoyo]

Okay, assuming you have a representative sample, no biases.

Let's suppose you have hat, with numbers in it. There are 10 tens and one each of 0-9. Each number 0-9 is relatively rare, compared to the 10s.

So let's draw a sample from the hat. Our probability of drawing a 10 is 10/20 or 50%. Our probability of drawing a NOT 10 is also 10/20. Suppose we draw two samples, one is a ten, one is a 3. Not knowing anything about the numbers in the hat (how many there are, how many of each kind there are or even W

Re:

[cswiger2005]

Excellent reply; thanks. Of course, I believe the TFA said that astronomers have seen two "puffy" planets out of ten samples being drawn, not just one; but your point about the difference between a PARTICULAR rare item versus a SPECIFIC rare item is still relevant until we get enough samples to have a better feel for the variation out there.

We've observed around 180 exoplanets via Doppler and have ten which perform transits; how many do we have to observe before we start getting a feel for the more common

Re:

[ceoyoyo]

Yup, it did. I think the article said that we've observed eleven transiting planets (which is eleven chances to observe a puffy planet). Out of those, we've now seen two.

Once you see two quite similar ones you can be much more confident that puffy planets are actually somewhat common. If you see nine regular planets and two puffy ones it's unlikely that the puffy ones are actually very rare, which is why the astronomer in the article is speculating that they might be common.

There could easily be LOTS of

Re:

[be-fan]

There is no statistical reason for why that would be truel. It all depends on whether a sample size of 10 is statistically significant for the population in question. For a classroom, it may be. For the universe? Likely not.

Re:

[ceoyoyo]

How do you know if your sample size is statistically significant? You have to know something about how diverse the population is. If the population is very uniform, only a few samples are fine. If it's very diverse, you need a lot of samples to accurately characterize it.

Finding ten regular planets and one puffy one gives you an idea that most planets are probably regular ones, but doesn't really tell you much about the character of the population. There might be only regular planets and puffy planets,

Two is impossible..

[Kozar_The_Malignant]

"The number two is impossible," - Isaac Asimov in The Gods Themselves.

The meaning being that there may be none of something in the universe, there may be one of something, but if there are two, there are lots more than two. Actually, in this case he was referring to universes themselves, not just things in the univrerse, but the point is the same.

Re:

[EsbenMoseHansen]

Counterexample: Regular polyhedron in ( 3 dimensions ): The tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron. That's 5, and all there is.

And on the topic at hand: The claim were that these things are common. If they are really rare, there might still be a lot of them.

Re:

[gEvil (beta)]

The claim were that these things are common.

No, the claim was that they "suspect" they might be common. There's a big difference between declaring that something "is" and stating that something "might be."

Re:

[EsbenMoseHansen]

I was referring to an ancestor, not the article...

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[ChrisMaple]

"if there are two, there are lots more than two."

Such as polarities. There's positive and negative, so there must be lots more.

Integers can be odd or even, so there must be lots more varieties of integers.

Re:

[ivanmarsh]

I love astronomy. In what other science does discovering two instances of the same thing make something potentially 'common'?

In the universe finding even one instance of anything makes it potentially common.

Re:Astronomers...

[i_should_be_working]

A biologist, a physicist and a mathematician are sitting at a cafe patio sipping coffee and watching the people go by. They see two people enter a nearby building. A few minutes later three people come out of the building.
 
'Ah,' the biologist says, 'they must have reproduced'.
 
'Nah,' says the physicist, 'three is within statistical error of two'.
 
'Well,' says the mathematician, 'one thing is for certain: if someone walks into the building now, it will be empty'.

Re:

[NPN_Transistor]

Imagine if you have a gigantic bag that has 5,000,000 marbles in it. Let's say that 1% of the marbles are black. 1% certainly sounds like a small number, but if you do the math it means that there are 50000 black marbles. That's a lot. The reason why there are a lot of black marbles is because there are so many marbles in total. If there are five billion marbles in total, then there will be 50 million black marbles in the bag. You can apply the same concept to planets. Right now around 200 extrasolar plane [usatoday.com]

Re:

[zimus]

what is that in libraries of congress? or volkswagens? or Oprahs?

It's probably more appropriate to compare Oprah's density to that of a black hole...

marshmallow

[gEvil (beta)]

Maybe they're made of marshmallow. You ever seen how big one of those things can get in the microwave?

Re:

[crunch_ca]

Obligatory Homer:

Mmmm.... Marshmallow

New Scientist

[HatchedEggs]

They usually do a pretty good job with new science (and space) news. Plus, they have an interesting podcast, if you guys haven't listened to it before.

As to the link, for some reason the newscientistspace.com site isn't accessible to me at the moment. It is quite strange that there exist planets with such a low density. It would be very interesting to be able to send a mission to a planet like this some day and find out a little more about what factors possibly came together to create something with such a

Re:

[ObjetDart]

It would be very interesting to be able to send a mission to a planet like this some day and find out a little more about what factors possibly came together to create something with such a low density.

Dude, if we ever have the ability to send missions that far, I say F the puffed up cork planets and head straight for the earth-like ones, that's where the action is.

Obligatory "It's so dense it will float..."

[Covalent]

Yes, but where do you get a bathtub that big?

so where's the wine bottle?

[jimstapleton]

Where's the wine bottle to use it on? I think wineries should start working on that now.

They found it!

[foistboinder]

Looks like they found Majipoor [wikipedia.org].

Re:

[dpilot]

Either that, or perhaps Dhrawn (Hal Clement) or Cuckoo. (Frederik Pohl and Jack Williamson)

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[rufty_tufty]

Maybe we found our first Mega Structure

http://en.wikipedia.org/wiki/Globus_Cassus [wikipedia.org]
  Would explain a few things...

Drats!

[Atomm]

When I read Puffed Up Planet, I thought it was new geeky cereal. :(

Good grief.

[julesh]

If the cork is 1.38 Jupiter Volumes, how big was the bottle?!?

Re:

[bunions]

> If the cork is 1.38 Jupiter Volumes, how big was the bottle?!?

about 460 billion km: http://www.physorg.com/news63346824.html [physorg.com]

puffed-up planets, eh?

[Glog]

A similarly bloated planet has been found before (HD 209458b), so these puffed-up planets may be quite common.
Right you are, Ken, you needn't look further than Kirstie Alley [blogs.com].

Ah, the speculation

[jense]

So, a twice-observed occurence makes a possibly common universal feature, and to explain it, we have a poorly-understood mechanism that somehow does something we don't understand with an effect we can't mimic. Ah, the joys of physics. :-)

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[PFI_Optix]

Yes, but it's also entirely possible that those are the only two such planets out of thousands that we'll eventually identify. That would not be "common".

Mating Displays

[the phantom]

I think it is facinating that scientists can now observe the mating rituals of planets. I assume that these planets are making themselves look larger for potential mates. Soon, we will have scores of baby planets running around, which might answer questions about litter sizes among planets.

Another possibility

[ArcherB]

A similarly bloated planet has been found before (HD 209458b), so these puffed-up planets may be quite common

Maybe these bloated planets are the only large enough for us to be able to see at this point.

Re:

[merlin_jim]

Maybe these bloated planets are the only large enough for us to be able to see at this point.

There are certainly limits to the lower range of sizes of planets we can detect - and since most detection methods work based on gravitational influence, it is apparent that a large worlds close in to its sun will be easier to detect than a small one far away.

Many of the first planets we found were very large with very close orbits, however recently we've been able to detect terrestrial - "rocky" that is as opposed

Re:

[cswiger2005]

I agree that is it much easier to detect bigger planets than small ones, and to detect planets close to the star than ones farther out, but the most successful mechanism for detecting planets is the radial-velocity doppler method, which doesn't care how dense the planet is, just how much it weighs. That method can be combined with the transit method to obtain confirmation and a much more accurate estimate of the planet's true mass, for the relatively few number of systems where the geometry is such that we

Less Dense than a Wine Cork...

[trongey]

But will they ever find a planet more dense than a Slashdot editor?

Re:

[jamstar7]

Eventually. But I have my doubts if they'll find one denser than a neocon politician...

Hmmm

[popsicle67]

I see my self as a child being disappointed the moon wasn't made of green cheese and now I'm told there are Sta-Puff Marshmallow planets, Cooooool!

do these rings make me look fat?

[treeves]

Bloated planet? They really need to observe it for a few *months* and make sure there's no periodicity to it, just in case. Ba-dum-bump.

Bloated Planets?

[SlideWRX]

That's what they look like after they are done mining them for the denser, rarer materials.

o.0

Not planets

[syousef]

These are no longer classified as planets. They do not orbit the sun. The recent stupid IAU definition of a planet says if it doesn't orbit the sun (not a sun or a star but the sun) it's not a planet. Same for 'dwarf planet'

I propose we call them extrasolar goobledygooks. Perhaps the IAU will vote that in too.

Re:

[Natzapo]

Actually, the IUA 2k6 redefinition of a planet it set to apply only within this solar system, and therefore has no provision for extrasolar planets. (see http://www.answers.com/topic/2006-redefinition-of- planet-1 [answers.com])

Personally, I think they could find more important things on which to waste their time ... but, c'est la vie.

Re:

[syousef]

Actually, the IUA 2k6 redefinition of a planet it set to apply only within this solar system, and therefore has no provision for extrasolar planets

Isn't that just an (admittedly better worded) restatement of what I just said?

Frankly I think the IAU have managed to look like a bunch of bafoons. There are so many things wrong with the definition as compared with hundreds of years of usage, and doing an about face after their first press release makes them look assinine.