A near-infrared transmission spectrum for the warm Saturn HAT-P-12b

Journal Article · Sun Dec 01 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/2/183· OSTI ID:22341912

Line, Michael R.; Knutson, Heather; Desert, Jean-Michel ^[1]; Deming, Drake; Wilkins, Ashlee ^[2]

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1. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)
2. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

We present a Hubble Space Telescope Wide Field Camera-3 (WFC3) transmission spectrum for the transiting exoplanet HAT-P-12b. This warm (1000 K) sub-Saturn-mass planet has a smaller mass and a lower temperature than the hot Jupiters that have been studied so far. We find that the planet's measured transmission spectrum lacks the expected water absorption feature for a hydrogen-dominated atmosphere and is instead best described by a model with high-altitude clouds. Using a frequentist hypothesis testing procedure, we can rule out a hydrogen-dominated cloud-free atmosphere to 4.9σ. When combined with other recent WFC3 studies, our observations suggest that clouds may be common in exoplanetary atmospheres.

• OSTI ID: 22341912
• Journal Information: Astrophysical Journal, Vol. 778, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
ALTITUDE
HYDROGEN
HYPOTHESIS
JUPITER PLANET
MASS
RADIO TELESCOPES
SATELLITE ATMOSPHERES
SATELLITES
SATURN PLANET
SPACE
SPECTRA
TRANSMISSION
WATER