Astrophys. J. 710, L35–L38 (2010)

Astronomers have for the first time directly captured the spectrum of light emitted by a planet orbiting a Sun-like star outside the Solar System. Space telescopes have previously measured spectra from planets beyond the Solar System — a way to learn about their atmospheres — although this could only be done in the rare cases in which a planet was in front of or behind its star in relation to Earth.

Markus Janson of the University of Toronto in Canada and his colleagues needed almost six hours of time on the Very Large Telescope in Chile to obtain the direct spectrum of the young, massive and hot planet called HR 8799c. It doesn't match modelled spectra for a typical hot planet, suggesting that HR 8799c might be surrounded by dust or that its atmosphere is still mixing turbulently.