Re: conplaneteering
| From: | Roger Mills <rfmilly@...> |
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| Date: | Friday, February 11, 2005, 22:48 |
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Mark J. Reed wrote:
> I'm trying to calculate the orbital period of an Earth-sized planet at
> 15 AUs out from a star that's about 7.5 times the mass of the Sun. I'm
> guestimating around 50 years, but Kepler's laws don't seem to be much
> help when looking for absolutes; you need a known quantity within the
> same solar system to compare against. Can anyone point me at the
> correct formulae?
>
Using the formula at
http://curriculum.calstatela.edu/courses/builders/lessons/less/les1/kepler3_2.html
(all one line)--
year^2 = AU^3 or x^2 = 15^3=3375
sq.root of 3375 is approx. 58.1 (x Earth year [=l])
Accuracy not guaranteed!!
you might want to look at the rest of that calstatela site too, if you
haven't already. Note that she seems to be using simplified versions of some
formulae, and I'm not sure how much difference that makes. AFAIK, it all
worked for Cindu....:-)))