forwarded on behalf of Amanda Baker

["Dr. H. Paul Shuch" <n6tx@setileague.org>]

Greetings, all,

        Just a brief reply I'm afraid, but hope it helps.

Rashid Faizullin

>planet near H209458 -
>Basic data:
>          M:      0.69 ± 0.05 MJ
>          Radius:
>               1.54 ± 0.18 RJ (Mazeh et al. 2000)
>               1.42 ± 0.08 RJ (Henry et al., 1999)
>          Semi-major axis:      ~ 0.045 AU
>http://www.obspm.fr/encycl/HD209458.html
>
>Note  there are no hydrogen of course but density of the planet
>is equal to 1/5 Jupiters density !
>May be it hollow ?

        Why do you say, there is no hydrogen? Remembering that
Jupiter probably has a rocky core of about 10 Earth masses, I
suggest that you re-do your calculations, assuming that H209458b
is at a much higher temperature than Jupiter due to its proximity
to its primary star, and predominantly consists of hydrogen and
helium in primordial proportions.

        Thanks,

        Amanda Baker

(teaching a course in Planetary Science this semester...)