The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy1-4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality5-9. Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6-2.8 μm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy-element enhancement ('metallicity') of about 10-30 times the solar value, a sub-solar carbon-to-oxygen (C/O) ratio and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-grey clouds with inhomogeneous coverageof the planet's terminator.

Feinstein, A.d., Radica, M., Welbanks, L., Murray, C.a., Ohno, K., Coulombe, L., et al. (2023). Early Release Science of the exoplanet WASP-39b with JWST NIRISS. NATURE, 614(7949), 670-675 [10.1038/s41586-022-05674-1].

Early Release Science of the exoplanet WASP-39b with JWST NIRISS

Mancini, Luigi;
2023-02-01

Abstract

The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy1-4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality5-9. Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6-2.8 μm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy-element enhancement ('metallicity') of about 10-30 times the solar value, a sub-solar carbon-to-oxygen (C/O) ratio and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-grey clouds with inhomogeneous coverageof the planet's terminator.
feb-2023
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/05
English
Astrophysics - Earth and Planetary Astrophysics
Astrophysics - Instrumentation and Methods for Astrophysics
Astrophysics - Solar and Stellar Astrophysics
Feinstein, A.d., Radica, M., Welbanks, L., Murray, C.a., Ohno, K., Coulombe, L., et al. (2023). Early Release Science of the exoplanet WASP-39b with JWST NIRISS. NATURE, 614(7949), 670-675 [10.1038/s41586-022-05674-1].
Feinstein, Ad; Radica, M; Welbanks, L; Murray, Ca; Ohno, K; Coulombe, L; Espinoza, N; Bean, Jl; Teske, Jk; Benneke, B; Line, Mr; Rustamkulov, Z; Saba, A; Tsiaras, A; Barstow, Jk; Fortney, Jj; Gao, P; Knutson, Ha; Macdonald, Rj; Mikal-Evans, T; Rackham, Bv; Taylor, J; Parmentier, V; Batalha, Nm; Berta-Thompson, Zk; Carter, Al; Changeat, Q; Dos Santos, La; Gibson, Np; Goyal, Jm; Kreidberg, L; López-Morales, M; Lothringer, Jd; Miguel, Y; Molaverdikhani, K; Moran, Se; Morello, G; Mukherjee, S; Sing, Dk; Stevenson, Kb; Wakeford, Hr; Ahrer, E; Alam, Mk; Alderson, L; Allen, Nh; Batalha, Ne; Bell, Tj; Blecic, J; Brande, J; Caceres, C; Casewell, Sl; Chubb, Kl; Crossfield, Ijm; Crouzet, N; Cubillos, Pe; Decin, L; Désert, J; Harrington, J; Heng, K; Henning, T; Iro, N; Kempton, Em; Kendrew, S; Kirk, J; Krick, J; Lagage, P; Lendl, M; Mancini, L; Mansfield, M; May, Em; Mayne, Nj; Nikolov, Nk; Palle, E; Petit Dit de la Roche, Djm; Piaulet, C; Powell, D; Redfield, S; Rogers, Lk; Roman, Mt; Roy, P; Nixon, Mc; Schlawin, E; Tan, X; Tremblin, P; Turner, Jd; Venot, O; Waalkes, Wc; Wheatley, Pj; Zhang, X
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/316798
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