Journal
NATURE
Volume 548, Issue 7665, Pages 58-+Publisher
NATURE PUBLISHING GROUP
DOI: 10.1038/nature23266
Keywords
-
Categories
Funding
- NASA
- European Research Council under the European Union [336792]
- ERC [724427]
- NASA [HST-GO-14767]
- NASA Postdoctoral Program
- NASA Exoplanets Research Program
- Royal Astronomical Society Fellowship
- National Centre for Competence in Research PlanetS by the Swiss National Science Foundation (SNSF)
- CNES
- French Agence Nationale de la Recherche (ANR) [ANR-12-BS05-0012]
- Spanish MINECO [AYA2014-54348-C3-2-R]
- NSF
- Tennessee State University
- State of Tennessee through its Centers of Excellence programme
- CNES (France)
- European Research Council (ERC) [336792, 724427] Funding Source: European Research Council (ERC)
Ask authors/readers for more resources
Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere(1-3). If upper layers are cooler than lower layers, molecular gases will produce absorption features in the planetary thermal spectrum(4,5). Conversely, if there is a stratosphere-where temperature increases with altitude-these molecular features will be observed in emission(6-8). It has been suggested that stratospheres could form in highly irradiated exoplanets(9,10), but the extent to which this occurs is unresolved both theoretically(11,12) and observationally(3,13-15). A previous claim for the presence of a stratosphere(14) remains open to question, owing to the challenges posed by the highly variable host star and the low spectral resolution of the measurements(3). Here we report a near-infrared thermal spectrum for the ultrahot gas giant WASP-121b, which has an equilibrium temperature of approximately 2,500 kelvin. Water is resolved in emission, providing a detection of an exoplanet stratosphere at 5 sigma confidence. These observations imply that a substantial fraction of incident stellar radiation is retained at high altitudes in the atmosphere, possibly by absorbing chemical species such as gaseous vanadium oxide and titanium oxide.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available