Vol. 577
In section 10. Planets and planetary systems

Spectrally resolved detection of sodium in the atmosphere of HD 189733b with the HARPS spectrograph

by A. Wyttenbach, D. Ehrenreich, C. Lovis, S. Udry, and F. Pepe, A&A 577, A62


The authors obtained the first ever high-resolution spectrum of the sodium doublet in the hot Jupiter HD 189733b with the HARPS spectrograph. They analyzed the line shapes to provide constraints on the temperature in the low-pressure atmosphere. The temperatures increase from 1500 K in the lower atmosphere to about 3300 K 10,000 km above this layer. Measurements like this will enable a much better characterization of the upper atmospheres of these planets and will help understanding their mass-loss rates.