It has been shown that an Earth-size planet or a super-Earth, in resonance
with a transiting Jupiter-like body in a short-period orbit around an M star,
can create detectable TTV signals (Kirste \& Haghighipour, 2011). Given the low
masses of M stars and their circumstellar disks, it is expected that such a
transiting giant planet to have formed at large distances and migrated to its
close-in orbit. That implies, if such systems are discovered around M stars,
the terrestrial planet had to form during the migration of the giant planet.
The formation of this object may be either in-situ (in a close-in orbit)
followed by its capture in resonance, or the object is formed at larger
distances where it was subsequently captured in a resonance with the migrating
giant planet. We have investigated these two scenarios by simulating the
dynamics of a disk of protoplanetary embryos and the formation of terrestrial
planets during the migration of a Jupiter-like planet around an M star. Results
suggest that unless the migration of the giant planet is very slow (slower than
1E-7 AU/year), it is unlikely that the close-in terrestrial planet is formed
in-situ. If a terrestrial planet is detected in a mean-motion resonance with a
close-in giant planet around an M star, the terrestrial planet was most likley
formed at large distances and carried to its close-in resonant orbit by the
migrating giant body.Comment: 8 pages, 3 figures, to appear in "Detection and dynamics of
transiting exoplanets" (ed. F. Bouchy, R. F. Diaz, C. Moutou
