Examinando por Autor "Gibson, Neale P."
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Ítem Constraints on TESS albedos for five hot Jupiters(Oxford University Press, 2022-07-01) Blažek, Martin; Kabáth, Petr; Piette, Anjali A. A.; Madhusudhan, Nikku; Skarka, Marek; Šubjak, Ján; Anderson, David R.; Boffin, Henri M. J.; Cáceres, Claudio C.; Gibson, Neale P.; Hoyer, Sergio; Ivanov, Valentin D.; Rojo, Patricio M.Photometric observations of occultations of transiting exoplanets can place important constraints on the thermal emission and albedos of their atmospheres. We analyse photometric measurements and derive geometric albedo (Ag) constraints for five hot Jupiters observed with TESS in the optical: WASP-18 b, WASP-36 b, WASP-43 b, WASP-50 b, and WASP-51 b. For WASP-43 b, our results are complemented by a VLT/HAWK-I observation in the near-infrared at 2.09μm. We derive the first geometric albedo constraints for WASP-50 b and WASP-51 b: Ag < 0.445 and Ag < 0.368, respectively. We find that WASP-43 b and WASP-18 b are both consistent with low geometric albedos (Ag < 0.16) even though they lie at opposite ends of the hot Jupiter temperature range with equilibrium temperatures of ∼1400 K and ∼2500 K, respectively. We report self-consistent atmospheric models that explain broad-band observations for both planets from TESS, HST, Spitzer, and VLT/HAWK-I. We find that the data of both hot Jupiters can be explained by thermal emission alone and inefficient day-night energy redistribution. The data do not require optical scattering from clouds/hazes, consistent with the low geometric albedos observed. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.Ítem Early Release Science of the exoplanet WASP-39b with JWST NIRISS(Nature Research, 2023-02) Feinstein, Adina D.; Radica, Michael; Welbanks, Luis; Murray, Catriona Anne; Ohno, Kazumasa; Coulombe, Louis-Philippe; Espinoza, Néstor; Bean, Jacob L.; Teske, Johanna K.; Benneke, Björn; Line, Michael R.; Rustamkulov, Zafar; Saba, Arianna; Tsiaras, Angelos; Barstow, Joanna K.; Fortney, Jonathan J.; Gao, Peter; Knutson, Heather A.; MacDonald, Ryan J.; Mikal-Evans, Thomas; Rackham, Benjamin V.; Taylor, Jake; Parmentier, Vivien; Batalha, Natalie M.; Berta-Thompson, Zachory K.; Carter, Aarynn L.; Changeat, Quentin; dos Santos, Leonardo A.; Gibson, Neale P.; Goyal, Jayesh M.; Kreidberg, Laura; López-Morales, Mercedes; Lothringer, Joshua D.; Miguel, Yamila; Molaverdikhani, Karan; Moran, Sarah E.; Morello, Giuseppe; Mukherjee, Sagnick; Sing, David K.; Stevenson, Kevin B.; Wakeford, Hannah R.; Ahrer, Eva-Maria; Alam, Munazza K.; Alderson, Lili; Allen, Natalie H.; Batalha, Natasha E.; Bell, Taylor J.; Blecic, Jasmina; Brande, Jonathan; Caceres, Claudio; Casewell S.L.; Chubb, Katy L.; Crossfield, Ian J. M.; Crouzet, Nicolas; Cubillos, Patricio E.; Decin, Leen; Désert, Jean-Michel; Harrington, Joseph; Heng, Kevin; Henning, Thomas; Iro, Nicolas; Kempton, Eliza M.-R.; Kendrew, Sarah; Kirk, James; Krick, Jessica; Lagage, Pierre-Olivier; Lendl, Monika; Mancini, Luigi; Mansfield, Megan; May E.M.; Mayne N.J.; Nikolov, Nikolay K.; Palle, Enric; Petit dit de la Roche, Dominique J. M.; Piaulet, Caroline; Powell, Diana; Redfield, Seth; Rogers, Laura K.; Roman, Michael T.; Roy, Pierre-Alexis; Nixon, Matthew C.; Schlawin, Everett; Tan, Xianyu; Tremblin P.; Turner, Jake D.; Venot, Olivia; Waalkes, William C.; Wheatley, Peter J.; Zhang, XiThe 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. © 2023, The Author(s).