University of Florida | 31 Aug 2010
GTC OSIRIS Transiting Exoplanet Atmospheric Survey:Any driver who’s seen deer silhouetted by the headlights of an oncoming car knows that vital information can be conveyed by the outlines of objects.
Building on this concept, University of Florida astronomers have analyzed light passing through the upper atmosphere of the giant planet HD 80606 b, about 190 light years from Earth, and determined that its atmosphere contains the element potassium.
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Coincidentally, another team led by David Sing at the University of Exeter, in Devon, U.K., has just used the same technique to detect potassium in the atmosphere of XO-2b, another huge planet about 485 light years from Earth.
Both planets, known as gas giants, have extremely high temperatures by earthly standards – HD 80606 b reaches about 2,200 degrees Fahrenheit and XO-2b is about 1,700 degrees. That’s hot enough to vaporize potassium.
Together, these observations support previous computer models that predicted what the atmospheres of such planets would be like. The findings also demonstrate the value of a new observational technique that could one day aid in the characterization of planets that might support life. The two groups’ findings are available online at the arXiv preprint server, http://arxiv.org, and have been submitted to the journals Astronomy & Astrophysics and the Monthly Notices of the Royal Astronomical Society. Colón and Sing will present their findings at the ExoClimes 2010 conference to be held at the University of Exeter, Sept. 7-10.
The observational technique is called narrow-band transit spectrophotometry, and it can measure the light absorbed by the atoms and molecules in a planet’s atmosphere, said Eric Ford, a UF astronomy associate professor and Colón’s adviser.
Detection of potassium in XO-2b from spectrophotometry - DK Sing et al
- arXiv.org > astro-ph > arXiv:1008.4795 > 27 Aug 2010
transit spectrophotometry from the Gran Telescopio Canarias - KD Colón et al
- arXiv.org > astro-ph > arXiv:1008.4800 > 27 Aug 2010