DETECTION OF H2O AND EVIDENCE FOR TiO/VO IN AN ULTRA-HOT EXOPLANET ATMOSPHERE

By T. Evans, D. Sing, H. Wakeford, N. Nikolov, Gilda E. Ballester, B. Drummond, T. Kataria, Neale P. Gibson, D. S. Amundsen, J. Spake. 2016

123 citations recorded by the source corpus.

We present a primary transit observation for the ultra-hot (Teq ∼ 2400 K) gas giant expolanet WASP-121b, made using the Hubble Space Telescope Wide Field Camera 3 in spectroscopic mode across the 1.12–1.64 μm wavelength range. The 1.4 μm water absorption band is detected at high confidence (5.4σ) in the planetary atmosphere. We also reanalyze ground-based photometric light curves taken in the B, r′, and z′ filters. Significantly deeper transits are measured in these optical bandpasses relative to the near-infrared wavelengths. We conclude that scattering by high-altitude haze alone is unlikely to account for this difference and instead interpret it as evidence for titanium oxide and vanadium oxide absorption. Enhanced opacity is also inferred across the 1.12–1.3 μm wavelength range, possibly due to iron hydride absorption. If confirmed, WASP-121b will be the first exoplanet with titanium oxide, vanadium oxide, and iron hydride detected in transmission. The latter are important species in M/L dwarfs and their presence is likely to have a significant effect on the overall physics and chemistry of the atmosphere, including the production of a strong thermal inversion.

Subfields: Atmospheric Science, Electrical and Electronic Engineering, Spectroscopy

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

In Spectroscopy

Citations in the corpus

NO THERMAL INVERSION AND A SOLAR WATER ABUNDANCE FOR THE HOT JUPITER HD 209458B FROM HST/WFC3 SPECTROSCOPY (2016, background): “…exoplanets are rapidly transforming our knowledge of planetary atmospheres (Berta et al. 2012; Swain et al. 2012; Deming et al. 2013; Huitson et al. 2013; Kreidberg et al. 2014ab,15; Stevenson et al. 2014c; McCullough et al. 2014; Knutson et al. 2014; Fraine et al. 2014; Evans et al. 2016).”
Exoplanetary Atmospheres: Key Insights, Challenges, and Prospects (2019, unknown): “From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context.”
The Complete Transmission Spectrum of WASP-39b with a Precise Water Constraint (2017, methodology): “…(Na and K) and molecular (H2O) absorption in a range of exoplanet atmospheres with ground- and space-based telescopes (e.g. Charbonneau et al. 2002; Sing et al. 2011, 2015; Deming et al. 2013; Kreidberg et al. 2014; Stevenson et al. 2014; Nikolov et al. 2016; Sing et al. 2016; Evans et al. 2016).”
A Population Study of Gaseous Exoplanets (2017, methodology): “…b (Damiano et al. 2017), HD 209458 b (Deming et al. 2013), HD 189733 b (McCullough et al. 2014), WASP12 b (Kreidberg et al. 2015), WASP-31 b (Sing et al. 2015), WASP-43 b (Kreidberg et al. 2014a), WASP-101 b (Wakeford et al. 2017), WASP-121 b (Evans et al. 2016) and XO-1 b (Deming et al. 2013).”
TRANSITIONS IN THE CLOUD COMPOSITION OF HOT JUPITERS (2016, background): “To date, the signature of TiO has been found in the two of the hottest exoplanets (Haynes et al. 2015; Evans et al. 2016) but no con- vincing evidence has been found for cooler ones (Désert et al. 2008; Huitson et al. 2013).”
From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context (2018, background): “To explain this discrepancy, Evans et al. (2016) proposed that a supersolar abundance ratio of FeH over water could increase the opacities around 1.2µm and improve the fit to the observations.”
The 2020 release of the ExoMol database: Molecular line lists for exoplanet and other hot atmospheres (2020, methodology): “There is a new VOMYT line list for VO [112] which has been used to tentatively identify VO in the atmosphere of exoplanets [205, 206].”
Global Climate and Atmospheric Composition of the Ultra-hot Jupiter WASP-103b from HST and Spitzer Phase Curve Observations (2018, background): “…features, some show emission features, and some are consistent with blackbody models (Madhusudhan et al. 2011; Crossfield et al. 2012; Stevenson et al. 2014a; Haynes et al. 2015; Evans et al. 2016; Beatty et al. 2017a,b; Sheppard et al. 2017; Arcangeli et al. 2018; Mansfield et al. 2018).”
The ExoMol database: Molecular line lists for exoplanet and other hot atmospheres (2016, methodology): “There is a new VOMYT line list for VO [112] which has been used to tentatively identify VO in the atmosphere of exoplanets [205, 206].”
HST PanCET Program: A Cloudy Atmosphere for the Promising JWST Target WASP-101b (2017, methodology): “To extract the spectra we followed a similar method to Evans et al. (2016).”
ExoMol line lists – XVIII. The high-temperature spectrum of VO (2016, background): “Tentative detection of VO and TiO in the hot atmosphere of the hot exoplanet WASP-121b were recently reported by Evans et al. (2016).”