Examinando por Autor "Bean, Jacob L."

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    A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b
    (Nature Research, 2023-08) Coulombe, Louis-Philippe; Benneke, Björn; Challener, Ryan; Piette, Anjali A. A.; Wiser, Lindsey S.; Mansfield, Megan; MacDonald, Ryan J.; Beltz, Hayley; Feinstein, Adina D.; Radica, Michael; Savel, Arjun B.; Dos Santos, Leonardo A.; Bean, Jacob L.; Parmentier, Vivien; Wong, Ian; Rauscher, Emily; Komacek, Thaddeus D.; Kempton, Eliza M.-R.; Tan, Xianyu; Hammond, Mark; Lewis, Neil T.; Line, Michael R.; Lee, Elspeth K. H.; Shivkumar, Hinna; Crossfield, Ian J. M.; Nixon, Matthew C.; Rackham, Benjamin V.; Wakeford, Hannah R.; Welbanks, Luis; Zhang, Xi; Batalha, Natalie M.; Berta-Thompson, Zachory K.; Changeat, Quentin; Désert, Jean-Michel; Espinoza, Néstor; Goyal, Jayesh M.; Harrington, Joseph; Knutson, Heather A.; Kreidberg, Laura; López-Morales, Mercedes; Shporer, Avi; Sing, David K.; Stevenson, Kevin B.; Aggarwal, Keshav; Ahrer, Eva-Maria; Alam, Munazza K.; Bell, Taylor J.; Blecic, Jasmina; Caceres, Claudio; Carter, Aarynn L.; Casewell, Sarah L.; Crouzet, Nicolas; Cubillos, Patricio E.; Decin, Leen; Fortney, Jonathan J.; Gibson, Neale P.; Heng, Kevin; Henning, Thomas; Iro, Nicolas; Kendrew, Sarah; Lagage, Pierre-Olivier; Leconte, Jérémy; Lendl, Monika; Lothringer, Joshua D.; Mancini, Luigi; Mikal-Evans, Thomas; Molaverdikhani, Karan; Nikolov, Nikolay K.; Ohno, Kazumasa; Palle, Enric; Piaulet, Caroline; Redfield, Seth; Roy, Pierre-Alexis; Tsai, Shang-Min; Venot, Olivia; Wheatley, Peter J.
    Close-in giant exoplanets with temperatures greater than 2,000 K (‘ultra-hot Jupiters’) have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from the Hubble Space Telescope (HST) and Spitzer Space Telescope 1–3. However, previous studies have yielded inconsistent results because the small sizes of the spectral features and the limited information content of the data resulted in high sensitivity to the varying assumptions made in the treatment of instrument systematics and the atmospheric retrieval analysis 3–12. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS 13 instrument on the JWST. The data span 0.85 to 2.85 μm in wavelength at an average resolving power of 400 and exhibit minimal systematics. The spectrum shows three water emission features (at >6σ confidence) and evidence for optical opacity, possibly attributable to H−, TiO and VO (combined significance of 3.8σ). Models that fit the data require a thermal inversion, molecular dissociation as predicted by chemical equilibrium, a solar heavy-element abundance (‘metallicity’, M/H=1.03−0.51+1.11 times solar) and a carbon-to-oxygen (C/O) ratio less than unity. The data also yield a dayside brightness temperature map, which shows a peak in temperature near the substellar point that decreases steeply and symmetrically with longitude towards the terminators. © 2023, The Author(s).
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    A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270
    (Nature Research, 2019-12-01) Günther, Maximilian N.; Pozuelos, Francisco J.; Dittmann, Jason A.; Dragomir, Diana; Kane, Stephen R.; Daylan, Tansu; Feinstein, Adina D.; Huang, Chelsea X.; Morton, Timothy D.; Bonfanti, Andrea; Bouma, L. G.; Burt, Jennifer; Collins, Karen A.; Lissauer, Jack J.; Matthews, Elisabeth; Montet, Benjamin T.; Vanderburg, Andrew; Wang, Songhu; Winters, Jennifer G.; Ricker, George R.; Vanderspek, Roland K.; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Armstrong, James D.; Barkaoui, Khalid; Batalha, Natalie; Bean, Jacob L.; Caldwell, Douglas A.; Ciardi, David R.; Collins, Kevin I.; Crossfield, Ian; Fausnaugh, Michael; Furesz, Gabor; Gan, Tianjun; Gillon, Michaël; Guerrero, Natalia; Horne, Keith; Howell, Steve B.; Ireland, Michael; Isopi, Giovanni; Jehin, Emmanuël; Kielkopf, John F.; Lepine, Sebastien; Mallia, Franco; Matson, Rachel A.; Myers, Gordon; Palle, Enric; Quinn, Samuel N.; Relles, Howard M.; Rojas-Ayala, Bárbara; Schlieder, Joshua; Sefako, Ramotholo; Shporer, Avi; Suárez, Juan C.; Tan, Thiam-Guan; Ting, Eric B.; Twicken, Joseph D.; Waite, Ian A.
    One of the primary goals of exoplanetary science is to detect small, temperate planets passing (transiting) in front of bright and quiet host stars. This enables the characterization of planetary sizes, orbits, bulk compositions, atmospheres and formation histories. These studies are facilitated by small and cool M dwarf host stars. Here we report the Transiting Exoplanet Survey Satellite (TESS)1 discovery of three small planets transiting one of the nearest and brightest M dwarf hosts observed to date, TOI-270 (TIC 259377017, with K-magnitude 8.3, and 22.5 parsecs away from Earth). The M3V-type star is transited by the super-Earth-sized planet TOI-270 b (1.247−0.083+0.089R⊕) and the sub-Neptune-sized planets TOI-270 c (2.42 ± 0.13 R⊕) and TOI-270 d (2.13 ± 0.12 R⊕). The planets orbit close to a mean-motion resonant chain, with periods (3.36 days, 5.66 days and 11.38 days, respectively) near ratios of small integers (5:3 and 2:1). TOI-270 is a prime target for future studies because (1) its near-resonance allows the detection of transit timing variations, enabling precise mass measurements and dynamical studies; (2) its brightness enables independent radial-velocity mass measurements; (3) the outer planets are ideal for atmospheric characterization via transmission spectroscopy; and (4) the quietness of the star enables future searches for habitable zone planets. Altogether, very few systems with small, temperate exoplanets are as suitable for such complementary and detailed characterization as TOI-270.
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    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, Xi
    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. © 2023, The Author(s).