Detection of H-alpha Absorption in Exoplanetary Exospheres

Details Detection of H-alpha Absorption in Exoplanetary Exospheres Detection of H-alpha Absorption in Exoplanetary Exospheres

Sep 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011ess.....2.1204r&link_type=abstract

American Astronomical Society, ESS meeting #2, #12.04

Astronomy and Astrophysics

Astrophysics

Scientific paper

The number of exoplanets with detected atmospheres is rapidly increasing. Particularly intriguing are detections of hydrogen that are attributed to the upper, unbound portion of their atmospheres (i.e., the exospheres) and indicate that some gas giants may be evaporating. Exospheric hydrogen has been detected in Lyman-alpha in the ultraviolet. We present the first detection of hydrogen absorption in H-alpha in the optical, which can be used to study hydrogen level populations and make measurements of the excitation temperature and density of hydrogen in these exospheres. We present a comparative survey of four transiting systems, based on high resolution optical spectra taken with the 9.2 meter Hobby-Eberly Telescope. We clearly detect H-alpha absorption (1.5% over the H-alpha feature) at the 4.6 sigma level for HD189733, and put strong limits on detections in our other systems. These measurements will provide important constraints on models of hydrodynamical atmospheric escape from these planets. Two systems (HD209458 and HD189733) have complementary Lyman-alpha detections. The detection of exospheric absorption in the optical of H-alpha provides a new window into the physical properties of these planetary atmospheres, and ensures access to exospheric measurements even after the end of HST and our capability to acquire UV spectra. This work is supported by the National Science Foundation through an Astronomy and Astrophysics Research Grant (AST-0903573).

Affiliated with

Also associated with

No associations

Rating

Detection of H-alpha Absorption in Exoplanetary Exospheres 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 Detection of H-alpha Absorption in Exoplanetary Exospheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of H-alpha Absorption in Exoplanetary Exospheres will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-832715