All...

A new transiting planet...

Not sure is this is the appropriate forum, but the extra solar planet hunters are coming up with some really odd discoveries..... this latest one seems right out of science fiction .... a super hot Mesklin... HAT-P-2b is an 8 jup mass, radius 1.18 jup, density 6.6gm/c3 planet (?) that orbits the F8 star HD147506 in 5.63 days at an orbital separation of 0.0685 AU and an eccentricity of 0.5e. But according to researchers its radius fits right on the theoretical curves for a super massive planet due to extreme electron degeneracy pressure. See http://oklo.org/?p=208

Or perhaps we have a cryptoplanet? See http://fr.arxiv.org/abs/0704.2860

Whew!!!!

Popular Articles
http://www.spaceref.com/news/viewpr.html?pid=22544
http://www.space.com/scienceastronomy/0705...ive_planet.html

Paper
http://fr.arxiv.org/abs/0705.0126

Mesklin.... anyone read Hal Clement?
http://en.wikipedia.org/wiki/Mesklin

Hot jupiters, hot neptunes, evaporating worlds, carbon planets, pulsar planets, water worlds, variety galore....

Craig

That Meslkin would need an asbestos hided Barlenan.

Mesklin had a rotation rate measured in minutes, meaning equatorial gravity was 3 gs while polar gravity went to over 800 (if I remember right). Clement described it as "disc-shaped." (More like "discus-shaped.")

Anyway, I don't see anything about HAT-P-2b's rotation rate, so what makes it like Mesklin?

--Greg

Mesklin was a terrestrial planet with equatorial radius half that of Jupiter. Its polar radius was less than half of that, so it was very oblate because of the extremely fast rotation speed. It was based on the tentative 16 M_J object around 61 Cygni B.

It is almost certain that HAT-P-2b is tidally locked with its orbital period. The great eccentricity should complicate the issue (extreme libration; a non-1:1 tidal lock like Mercury's is out of question?)

Except it had liquid methane oceans; if you think that's "terrestrial" what part of Terra are you from?

Oh! Never mind! :-)

--Greg

Well, it's not that cold here (...although it sometimes feels that).

Of course, when extrasolar planets are concerned, "terrestrial" means the planet has a solid surface as opposed to a gas giant which doesn't have one.

Trouble is, back when Clement was writing his novels, most authors assumed Jupiter had a solid surface as well. Check out "Victory Unintentional" by Asimov or "Three Worlds to Conquer" by Poul Anderson -- and that's just in the "A" section. :-)

--Greg

full quote removed - Doug

The first is from 1942, which is not surprising, but the second seems to be as late as 1964 -- unless it's a re-titling of an older story. When did the lack of a solid surface on Jupiter (and other giant planets) become common knowledge?

Three Worlds to Conquer may have an earlier serialized publication, or it may be a Fixup from several previously published novellas. The copyright date on some SF is the date of final "assembly and publication".

Till the idea of an entirely "gaseous - transitioning - to - supercritical - fluids" atmosphere and "envelope" for giant planets was rigorously worked out together with the realization that such an atmosphere would be adiabatic and convecting down to super-pressured and super-heated depths, the giant planets "did not compute" and sometimes even good writers just ignored confusing reality in favor of pure story.

Another Anderson, one that's a classic despite it's inaccuracy, that's set ON Jupiter is "Call Me Joe" from about 1957 Astounding: http://www.noosfere.com/showcase/IMAGES/ast_5704.jpg

I loved "Three Worlds to Conquer". My reasoning for starting this thread was really, old guy that I am, just my amazement at how varied are the planets being found. When I first read "Mission of Gravity" I thought a planet on such an eccentric orbit was just crazy. You have to remember that after the whole Velikovsky thing in the fifties and sixties, the IDEA of eccentric and MIGRATING planets was considered something of a heresy. We inhabited a solar system where all the planets seemd to have formed inplace in a neat and tidy disk that was chemically segregated by temperature. Planetary orbits did not cross.

And then, after so MANY false detections, there came 51 Pegasi b .... a gas giant closer to it's sun than Mercury. What a wow that was and some researchers refused to believe these were really planets until the first transiting body, HD 206458 was tracked in 1999.

Now with STARDUST results implying some mixing of hot and cold material in disks, and the detectiom of so many hot and eccentric gas giants... well, for a guy born in the fifties, this is very weird and exotic stuff.

As for Mesklin... wish there really was such a place out there... perhaps in a trillion or a few billlion years, some ice giants or gas giants will cool down enough to allow giant ice balls with hydrogen breathers to evolve. There is hope yet for a Barlenan.

Craig

Craig: I hear you on that. To tell you the truth, I didn't really believe the theories about migrating planets until Alan Stern responded to one of my posts here to tell me that, yes, real scientists DID believe this now.

But that still doesn't validate Velikovsky. ;-) It was all over long before Man evolved, so unlikely to have been involved in any Bible stories.

--Greg