Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets

Details Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets

2007-11-13

arxiv.org/abs/0711.2015v1

Astronomy and Astrophysics

Astrophysics

Accepted to MNRAS. 14 pages, 4 figures, 1 table

Scientific paper

10.1111/j.1365-2966.2007.12712.x

To date, two planetary systems have been discovered with close-in, terrestrial-mass planets (< 5-10 Earth masses). Many more such discoveries are anticipated in the coming years with radial velocity and transit searches. Here we investigate the different mechanisms that could form "hot Earths" and their observable predictions. Models include: 1) in situ accretion; 2) formation at larger orbital distance followed by inward "type 1" migration; 3) formation from material being "shepherded" inward by a migrating gas giant planet; 4) formation from material being shepherded by moving secular resonances during dispersal of the protoplanetary disk; 5) tidal circularization of eccentric terrestrial planets with close-in perihelion distances; and 6) photo-evaporative mass loss of a close-in giant planet. Models 1-4 have been validated in previous work. We show that tidal circularization can form hot Earths, but only for relatively massive planets (> 5 Earth masses) with very close-in perihelion distances (< 0.025 AU), and even then the net inward movement in orbital distance is at most only 0.1-0.15 AU. For planets of less than about 70 Earth masses, photo-evaporation can remove the planet's envelope and leave behind the solid core on a Gyr timescale, but only for planets inside 0.025-0.05 AU. Using two quantities that are observable by current and upcoming missions, we show that these models each produce unique signatures, and can be observationally distinguished. These observables are the planetary system architecture (detectable with radial velocities, transits and transit-timing) and the bulk composition of transiting close-in terrestrial planets (measured by transits via the planet's radius).

Affiliated with

Also associated with

No associations

Rating

Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-271472