nai

Project Progress

D. Deming and his collaborators made new measurements of the temperature of the transiting extrasolar planet HD 209458b, using Spitzer observations of the planet’s secondary eclipse. The new observations indicate that the planet is somewhat hotter that the T ~ 1130° K temperature obtained from the initial Spitzer observations in 2005. Our undergraduate summer interns Catherine Elder (Cornell Univ.) and Kamen Todorov (Connecticut College) were deeply involved in the data analysis. Moreover, postdoctoral associate L. Jeremy Richardson worked with Deming and with undergraduate intern Karen Horning to publish the first spectrum of a planet orbiting another star.
Using Spitzer data, the team was able to measure the spectrum of HD 209458b in the infrared spectral region from 7 to 13 micrometers (Figure 1). They found evidence of thermal emission from silicate clouds, and a feature possibly due to polycyclic aromatic hydrocarbons. Their result was published in Nature on 22 February 2007. The technique used by this team to measure the spectrum – involving the secondary eclipse of this transiting planet – has potential application to obtain the spectra of transiting earth-like planets orbiting in the habitable zones of lower main sequence stars. This may eventually lead to the detection of biomarkers in extrasolar planetary spectra.

{{ 1 }}