Hot Jupiters clear with scattered clouds
*IMAGES*
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Astronomy and planetary science
Embargo
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London: Monday 14 December 2015 16:00 (GMT)
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New York: Monday 14 December 2015 11:00 (EST)
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Tokyo: Tuesday 15 December 2015 01:00 (JST)
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Sydney: Tuesday 15 December 2015 03:00 (AEDT)
The presence of clouds or hazes in the atmospheres of ‘hot’ Jupiter-like planets existing outside
our Solar System is supported by a study published online in Nature this week. Hot Jupiters are
extrasolar planets similar to Jupiter in size, but with tight orbits around their parent stars and very
high atmospheric temperatures.
Previous studies have shown that in some hot Jupiters, the spectra—measured when atoms in a
gas absorb or emit light at characteristic frequencies—are characterized by weak water
absorption lines. This could be a result of water depletion that took place when the planet
formed, or may have arisen as a result of clouds and hazes in the atmospheres of these
exoplanets. Using spectral data from instruments on board the Hubble Space Telescope and the
Spitzer Space Telescope, David Sing and colleagues analysed the atmospheres of ten hot
Jupiters, covering a range of wavelengths from 0.3 micrometres to 5 micrometres. The results
reveal a diverse range of atmospheres for these exoplanets, with a continuum from clear to
cloudy.
The authors also find that strong water absorption is a feature of exoplanets with a clear
atmosphere. On the basis of these results, they argue against primordial water depletion during
exoplanet formation, and propose that clouds and hazes are the cause of weaker spectral
signatures observed in these distant planets.
Article and author details
1. A continuum from clear to cloudy hot-Jupiter exoplanets
without primordial water depletion
Corresponding Author
David Sing
University of Exeter, Exeter, Devon, United Kingdom
Email: sing@astro.ex.ac.uk, Tel: +44 1392725652
DOI
10.1038/nature16068
Online paper*
http://nature.com/articles/doi:10.1038/nature16068
* Please link to the article in online versions of your report (the URL will go live after the embargo ends).
Geographical listings of authors
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France, Germany, United Kingdom & United States
Image 1
Caption: This image shows an artist’s impression of the ten hot Jupiter exoplanets studied by David
Sing and his colleagues. From top left to to lower left these planets are WASP-12b, WASP-6b,
WASP-31b, WASP-39b, HD 189733b, HAT-P-12b, WASP-17b, WASP-19b, HAT-P-1b and HD
209458b.
The images are to scale with each other. HAT-P-12b, the smallest of them, is approximately the size
of Jupiter, while WASP-17b, the largest planet in the sample, is almost twice the size. The planets are
also depicted with a variety of different cloud properties.
Credit: ESA/Hubble & NASA
Image 2
Caption: This image shows an artist’s impression of the ten hot Jupiter exoplanets studied by David
Sing and his colleagues.
The images are to scale with each other. HAT-P-12b, the smallest of them, is approximately the size
of Jupiter, while WASP-17b, the largest planet in the sample, is almost twice the size. The planets are
also depicted with a variety of different cloud properties.
Credit: ESA/Hubble & NASA