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Post Info TOPIC: Kepler-7b
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NASA Space Telescopes Find Patchy Clouds on Exotic World

Astronomers using data from NASA's Kepler and Spitzer space telescopes have created the first cloud map of a planet beyond our solar system, a sizzling, Jupiter-like world known as Kepler-7b.
The planet is marked by high clouds in the west and clear skies in the east. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.
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Blobrana


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Understanding Clouds as a Necessary Ingredient in the Search for Life: the Case Study of the Exoplanet Kepler-7b

An international team, with participation from the University of Bern, has produced the first map of clouds on an exoplanet using the Kepler Space Telescope. Studying the atmospheres of exoplanets is the path towards ultimately identifying life elsewhere in the Universe. Understanding the role of clouds in exoplanet atmospheres is a necessary ingredient in the cosmic hunt for life
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Title: The high albedo of the hot Jupiter Kepler-7b
Authors: Brice-Olivier Demory, Sara Seager, Nikku Madhusudhan, Hans Kjeldsen, Joergen Christensen-Dalsgaard, Michael Gillon, Jason F. Rowe, William F. Welsh, Elisabeth R. Adams, Andrea Dupree, Don McCarthy, Craig Kulesa, William J. Borucki, David G. Koch, the Kepler Science Team

Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations. The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass of 44±5 ppm. If directly related to the albedo, this translates to a Kepler geometric albedo of 0.32±0.03, the most precise value measured so far for an exoplanet. We also characterise the planetary orbital phase lightcurve with an amplitude of 42±4 ppm. Using atmospheric models, we find it unlikely that the high albedo is due to a dominant thermal component and propose two solutions to explain the observed planetary flux. Firstly, we interpret the Kepler-7b albedo as resulting from an excess reflection over what can be explained solely by Rayleigh scattering, along with a nominal thermal component. This excess reflection might indicate the presence of a cloud or haze layer in the atmosphere, motivating new modelling and observational efforts. Alternatively, the albedo can be explained by Rayleigh scattering alone if Na and K are depleted in the atmosphere by a factor of 10-100 below solar abundances.

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