Seven earth-sized planets discovered circling a star 39 light years from Earth

Re:Seven earth-sized planets discovered circling a star 39 l... by verandaguy on Wednesday February 22, 2017 @01:34PM (#13707855)

Depending on the spectrum of the star, I would be concerned about non-visible radiation doses when in close proximity to the star.

IANA astrophysicist, though.

Actually, adding onto that, I'm wondering whether orbits this tight would result in a noticeable centripetal force -- that is, that you'd feel lighter on the night side of the planet than on the day side.

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Re:Seven earth-sized planets discovered circling a star 39 l... by mturmon on Wednesday February 22, 2017 @01:43PM (#13707969)

Good point, this is in TFA:

"Although at least some fraction of each planet could harbor liquid water, it doesn't necessarily follow that they are habitable. TRAPPIST-1 emits about the same amount of X-ray and ultraviolet radiation as the Sun does, which could chew away at any protective atmospheres the planets might have."

But it's complicated. For example, apparently the energetic radiation can help by stripping away the H/He atmosphere. For more, see:

https://academic.oup.com/mnrasl/article-lookup/doi/10.1093/m...

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