Exoplanet Forecast: Hot and Wet
Ssc2007 12a

Credit: ESA, NASA/ JPL-Caltech/G. Tinett (Instiute d'Astrophysique de Paris, University College London)

Chart • July 11th, 2007 • ssc2007-12a


This plot of data from NASA's Spitzer Space Telescope tells astronomers that a toasty gas exoplanet, or a planet beyond our solar system, contains water vapor.

Spitzer observed the planet, called HD 189733b, cross in front of its star at three different infrared wavelengths: 3.6 microns, 5.8 microns, and 8 microns (see lime-colored dots). For each wavelength, the planet's atmosphere absorbed different amounts of the starlight that passed through it. The pattern by which this absorption varies with wavelength matches known signatures of water, as shown by the theoretical model in blue.

About the Object

HD 189733b
Planet > Special Cases > Transiting
Planet > Special Cases > Hot Jupiter
63 Light Years

Color Mapping

Band Wavelength Telescope
Infrared 3.6 µm Spitzer IRAC
5.8 µm Spitzer IRAC
8.0 µm Spitzer IRAC