2006/10/04 by Diana Valencia, Dimitar D. Sasselov, Rirchard J. O'Connell +1 · 4 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Exoplanet #Field (mathematics) #Planet #RADIUS #Solar System #Stellar, planetary, and galactic studies #Terrestrial planet #Transit (satellite) #astro-ph #physics.geo-ph
paper · pdf · doi:10.1086/509800
published as Astrophys.J.656:545-551,2007 · 22 pages, 3 tables, 5 figures; Article will appear in ApJ Jan 2007 issue
arxiv created 2006/10/04 · openalex publication_date 2007/02/03 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
With improving methods and surveys, the young field of extrasolar planet studies has recently expanded into a qualitatively new domain—terrestrial (mostly rocky) planets. The first such planets were discovered during the past year and a half, judging by their measured masses of less than 10 M ⊕ ("super-Earths"). They are introducing a novel physical regime that has not been explored before, as such planets do not exist in our solar system. Their compositions can be completely terrestrial, or they may harbor an extensive ocean (water and ices) above a rocky core. We model the structure and properties of the first super-Earth (mass ~7.5 M ⊕ ), discovered in 2005, illustrating the possible compositions and providing radius evaluations in view of future detection of similar planets by transits. We find that there exists a threshold in radius above which a super-Earth most certainly has an extensive water content. In the case of GJ 876d, this threshold is at about 12,000 km. Our results show that unique characterization of the bulk composition of super-Earths will be possible with future transit studies.