HR: 1340h
AN: SA53B-1179    [Abstracts]
TI: New Extra-Solar Planet - thermal state and structure
AU: * Valencia, D
EM: valencia@mail.geophysics.harvard.edu
AF: Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138 United States
AU: O'Connell, R J
EM: oconnell@mail.geophysics.harvard.edu
AF: Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138 United States
AU: Sasselov, D
EM: dsasselov@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 United States
AB: For the last decade astronomers have found more than 160 planets orbiting stars other than our sun. All but three of them are gaseous planets. The variety of characteristics of these newly discovered planets opens a new field with questions about planetary formation, structure and evolution, as well as the possibility of existence of life beyond our solar system. Planetary formation models suggested the existence of terrestrial extra-solar planets with masses up to 10 times the mass of the Earth. In June of 2005 the first Super-Earth was discovered orbiting a star 15 light years away with a mass that is about 7.5 times the mass of the Earth and a period of 1.94 days. The composition of this planet is unknown but probably has an Earth-like composition. Astronomers believe the surface temperature ranges between ~500 K and ~700 K. Liquid water can exist at temperatures above T=400K at high pressures (above 10 MPa) allowing for the possibility of a water layer on top of a rocky core. Our work focuses on determining scaling relationships with mass, internal structure parameters and thermal state. We explore the effects of a water/icy layer above a rocky core as well as other types of compositions in determining the internal structure. This water layer may convect causing the planet to have two layer convection. We explore the effects of a layer convection mode versus whole mantle convection for a Super-Earth. Due to the closeness of this planet to its parent star we can expect substantial tidal heating that can affect the thermal state of this planet. We explore the effects of tidal heating in the internal structure of a planet. Differences in composition have much larger effects in the mass-radius relationship than the uncertainties in thermodynamic parameters of the minerals composing the planet.
DE: 5400 PLANETARY SCIENCES: SOLID SURFACE PLANETS
DE: 5410 Composition (1060, 3672)
DE: 5430 Interiors (8147)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005