Scientists Find Distant Extrasolar Planet With Atmosphere

MurthyDN writes "The New York Times (Free Registration, man) has an article which says 'The Hubble Space Telescope has detected an extensive atmosphere of hydrogen enveloping and escaping from a newfound planet of a distant star, scientists reported yesterday. The discovery comes as no surprise, astronomers say, but is important nonetheless as apparent confirmation that the extrasolar planets observed so far not only are much like the solar system's Jupiter in size but also are similarly huge gaseous bodies.'"

Deja vu all over again

[infernow]

Roto-Rooter Man said it first [slashdot.org], but I agree:
Dupe. [slashdot.org]
The link's different, but the story's the same.
Guess the /. editors just can't resist "free registration [and so forth]" statements. ^_^

Old news

[barakn]

This was posted way back on March 13 here [slashdot.org]. There are links that don't require the intrusive NY Times registration. They are Spaceflightnow [spaceflightnow.com] and Nature [nature.com]

Can you imagine what kind of weather it would have

[geoswan]

Can you imagine what kind of weather it would have?

It would be receiving much more energy from its primary. Much more significant tides, too. The storms on this "Hot Jupiter" would make our Jupiter's Great Red Spot look like a spit in a bucket.

(If it comes from a star other than the Sun, would you still call it "insolation"?)

Hot Jupiter could lose entire atmosphere?

[geoswan]

Hot Jupiter could lose entire atmosphere?

IANAPhysicist, but is seems to me there is an implication of this suggestion that the articles don'e mention.

Short version: Losing all that mass will boost "hot jupiter" to a higher orbit. Wouldn't a "hot jupiter" become a merely "warm jupiter" before it lost its entire atmosphere?

This is the same phenomenon that stripped out the Hydrogen and Helium from the Earth's atmosphere. The individual gas molecules in a planet's atmosphere, have a range of velocities

Re:Hot Jupiter could lose entire atmosphere?

[CheshireCatCO]

That actually depends. If the planet were spinning rapidly, like Jupiter or Saturn, the planet would probably be pretty nearly isothermal. There is some doubt on that point, though, since planets this close to their primaries are likely tidally locked (in a 1:1 spin-orbit resonance), or at least in some low-order resonance (a la Mercury).

(Also, if it is spinning rapidly and NOT isothermal, you'll still get the bulk of the escape occuring off to one side of the planet-star line. It takes a while for an a

Hot Jupiter moves out

[geoswan]

HD 209458 is roughly similar to Sol. What would have been the effect of a "hot jupiter" boosting itself to a higher orbit in the early Solar System?

Bode's law: Tidal forces influenced the smaller planet's orbits to be in harmony with the real Jupiter. The same thing would happen if there were a hot jupiter in an inner orbin, wouldn't it?

And, as "hot jupiter" slowly boosted itself to the orbit of a merely "warm jupiter", would these smaller planets move outward too?

They aren't ejecting 90% of their mas

Re:Hot Jupiter moves out

[CheshireCatCO]

What do you mean by "harmony"? And Bode's law (as I've always seen it) doesn't work.

A hot Jupiter would have destroyed/removed any smaller inner planets as it migrated in. So there's no real issue there.

Re:Hot Jupiter moves out

[geoswan]

Well, I looked up your web-page, so I think I ought to be prepared to defer to you. Maybe I mis-spoke. Pluto, and those other recently discovered big Kuiper Belt objects? Aren't their orbits all 1.5 times that of Neptune? That is what I meant by harmony. Bode's law, there you have me. I couldn't restate it. I thought it merely described how the orbits of the Sun's smaller satellites were synchronized with Jupiter.

I visited your web-site, and looked at your talk about Pluto and Charon. I saw that yo

Re:Hot Jupiter moves out

[CheshireCatCO]

Ah, the term you want is "resonance". The simplist kind of resonance is a "mean motion" resonance wherein the bodies have orbital periods which are small-integer ratios. (3:2 for Pluto/Neptune, for instance.) The planets do not, in general, have orbtial resonances with each other. The fact that Pluto is in resonance with Neptune is, to some, a good reason to not call it a planet. In order to get into resonace, usually one of the bodies needs to be migrating. In Neptune's case, outward.

(The Titus-Bode