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Atmospheres of Super-Earth Exoplanets. Korey Haynes May 16, 2011. Image courtesy of NASA. Introduction to Super-Earths. 1-10 Earth masses Rocky make-up Discoveries just beginning. Images courtesy of NASA. Forcing and feedback mechanisms for an Earth-like atmosphere (Von Bloh 2007).
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Atmospheres of Super-Earth Exoplanets Korey Haynes May 16, 2011 Image courtesy of NASA
Introduction to Super-Earths • 1-10 Earth masses • Rocky make-up • Discoveries just beginning Images courtesy of NASA
Forcing and feedback mechanisms for an Earth-like atmosphere(Von Bloh 2007) Basics of atmospheric mechanisms
Atmospheric Formation Methods of atmospheric formation and resulting composition possibilities * Nebular capture * Degassing * Sublimation (Rogers 2010)Atmospheric loss:
Atmospheric Variations Atmosphere temperature and pressure are dependent on the composition of atmosphere.A plot of temperature vs. pressure, with lines denoting various mineral buffers (Schaefer & Fegley 2011)
(Showman 2009) As well as temperature/pressure gradients, rotation rates and the balance of forces given by the Rossby number are the main factors in global circulation.
Atmospheric circulation II Vorticity for a set of three model planets, identical except for the rate of rotation, which is zero on the left, medium in the middle, and rapid on the right (Showman 2009)
Geochemical cycles Biomarkers Spectra of a model atmosphere showing sulfur features detectable for missions such as JWST (Kaltenegger 2010) http://www.primalscience.com/?page_id=533
GJ 1214b 6.55 ± 0.98 Earth masses; 2.68 ± 0.13 Earth radii; 1.6 day period. First super-Earth with transmission spectra Significant gas envelope, probably water-based Gleise 581c and 581d 581c: 5.06 Earth masses, 0.073 AU 581d: 8.3 Earth masses, 0.25 AU Inner planet too hot Outer planet maybe too cold, but atmosphere could protect it. Case Studies
Atmospheric Composition (GJ 1214b) Spitzer measurements rule out H-rich atmosphere at 7 sigma level (Desert 2011).
Ranges for stable atmospheres (Gleise 581d) Surface temperature and partial pressure of carbon dioxide and water as a function of orbital distance (Selsis 2007).