another Planet HD149026b is hotter than some stars!!?

Question

it is a mere 279 light years away!! what do you think about this!!

Answer 1

Yes I read this (on the NASA website I think) and it surprised me, in the sense we tend to assume a Hot Jupiter "must be" cooler than a cool star.

I give a link to an article in Sky and Telescope magazine below in which the following struck me as interesting:

"The planet orbits just 0.042 a.u. (6.3 million miles) from the center of its star, much the same as Gliese 851b orbits from its star.

HD 149026b is not a place you'd want to visit. The surface gravity at the top of the core could be as high as 10 g's, and the overlying pressure and temperature would simultaneously scrunch and melt a human into an organic puddle.

A person would fare little better at the cloudtops, where the close proximity to the star — about 0.042 the average Earth-Sun distance — raises temperatures to a scalding 1,270° C (2,300° F).

Theorists are struggling to understand how any planet could accumulate so much heavy-element material. HD 149026b presumably formed when small planetesimals collided in a disk around the star during the star's infancy, building up a large rocky body that accreted more surrounding material.

But as Alan Boss notes, "I have not seen any core-accretion models that predict the formation of such a beast. I suspect that the core-accretion folks will be scratching their heads for awhile over how this thing could have formed." Saumon adds, "I don't think anyone has a plausible formation mechanism for this new planet yet."

Answer 2

i havent heard of this planet yet i need to research it, however i dont see how it could be hotter than "some" stars unless they mean its hotter than the surface of some stars. the only way to reach the temperature of a "star" is through nuclear fusion, and therefore if you are going through nuclear fusion you ARE a star. interesting thought though!!!!!!!

Answer 3

Considering that it orbits its star in 3 days, it must be incredibly close in...

Details here:
http://en.wikipedia.org/wiki/HD_149026_b