TY - CONF
T1 - The complete transmission spectrum of an exoplanet from UV to IR
AU - Pont, F.
AU - Sing, D.
AU - Huitson, C.
AU - Gibson, N.
AU - Gilliland, R.
AU - Knutson, H.
AU - Charbonneau, D.
AU - Desert, J.-M.
PY - 2011/10/1
Y1 - 2011/10/1
N2 - Transmission spectroscopy of transiting planets is one tool to obtain
atmospheric spectra of planets outside the solar system. Using four
different instruments on the HST - STIS, ACS, NICMOS and WF3 - we
combined wide-band and narrow-band spectrophotometry over dozens of HST
orbits to piece together the complete transmission spectrum of the hot
Jupiter prototype HD 189733b. These observations paint a very different
picture of the atmosphere of this planet than predicted by the models.
The transmission spectrum is dominated by Rayleigh scattering over the
whole visible and nearinfrared range, with narrow sodium and potassium
lines, and excess absorption in the UV. This is interpreted as
indicating an atmosphere dominated by haze over at least six scale
heights, with residual alkali metal absorption above the haze, and
possible opacity from photochemical products in the UV. Altogether the
atmosphere of HD 189733b seems to be more dominated by hazes or/and
clouds than expected for hot Jupiters, not unlike Solar System planets
like Venus or Titan. The only other well-studied case, the planet HD
209458b, has a transparent, absorbing atmosphere, suggesting the
existence of at least two families of hot gas giant planet atmospheres.
AB - Transmission spectroscopy of transiting planets is one tool to obtain
atmospheric spectra of planets outside the solar system. Using four
different instruments on the HST - STIS, ACS, NICMOS and WF3 - we
combined wide-band and narrow-band spectrophotometry over dozens of HST
orbits to piece together the complete transmission spectrum of the hot
Jupiter prototype HD 189733b. These observations paint a very different
picture of the atmosphere of this planet than predicted by the models.
The transmission spectrum is dominated by Rayleigh scattering over the
whole visible and nearinfrared range, with narrow sodium and potassium
lines, and excess absorption in the UV. This is interpreted as
indicating an atmosphere dominated by haze over at least six scale
heights, with residual alkali metal absorption above the haze, and
possible opacity from photochemical products in the UV. Altogether the
atmosphere of HD 189733b seems to be more dominated by hazes or/and
clouds than expected for hot Jupiters, not unlike Solar System planets
like Venus or Titan. The only other well-studied case, the planet HD
209458b, has a transparent, absorbing atmosphere, suggesting the
existence of at least two families of hot gas giant planet atmospheres.
M3 - Abstract
SP - 1602
ER -