Paper: astro-ph/0605061
Date: Tue, 2 May 2006 17:37:07 GMT (98kb)

Title: Rapid Formation of Super-Earths around M Dwarf Stars

Authors: Alan P. Boss

Comments: 13 pages, 2 figures, 1 table. Astrophysical Journal (Letters), in
press
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While the recent microlensing discoveries of super-Earths orbiting two M
dwarf stars have been taken as support for the core accretion mechanism of
giant planet formation, we show here that these planets could also have been
formed by the competing mechanism of disk instability, coupled with
photoevaporative loss of their gaseous envelopes by a strong external source of
UV radiation, i.e., an O star. M dwarfs that form in regions of future
high-mass star formation would then be expected to have super-Earths orbiting
at distances of several AU and beyond, while those that form in regions of
low-mass star formation would be expected to have gas giants at those
distances. Given that most stars are born in the former rather than in the
latter regions, M dwarfs should have significantly more super-Earths than gas
giants, as seems to be indicated by the microlensing surveys.

\\ ( http://arXiv.org/abs/astro-ph/0605061 , 98kb)