7 results on '"Casewell, Sarah L"'
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2. Visible extreme adaptive optics on extremely large telescopes: towards detecting oxygen in Proxima Centauri b and analogs
- Author
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Ruane, Garreth J., Fowler, J., Haffert, Sebastiaan Y., van Kooten, Maaike A. M., Landman, Rico, Bidot, Alexis, Hours, Adrien, N'Diaye, Mamadou, Absil, Olivier, Altinier, Lisa, Baudoz, Pierre, Belikov, Ruslan, Bonse, Markus Johannes, Bott, Kimberly, Brandl, Bernhard, Carlotti, Alexis, Casewell, Sarah L., Choquet, Elodie, Cowan, Nicolas B., Desai, Niyati, Doelman, David, Fogarty, Kevin, Gebhard, Timothy D., Gutierrez, Yann, Guyon, Olivier, Herscovici-Schiller, Olivier, Juanola-Parramon, Roser, Kenworthy, Matthew, Kleisioti, Elina, König, Lorenzo, Krasteva, Mariya, Laginja, Iva, Leboulleux, Lucie, Mazoyer, Johan, Millar-Blanchaer, Maxwell A., Mouillet, David, Por, Emiel, Pueyo, Laurent, Snik, Frans, van Dam, Dirk, van Gorkom, Kyle, and Vaughan, Sophia R.
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- 2023
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3. A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b
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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, and Wheatley, Peter J.
- Abstract
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 Telescope1–3. 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 analysis3–12. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS13instrument 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 >6σconfidence) 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+1.11times 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.
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- 2023
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4. Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H
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Alderson, Lili, Wakeford, Hannah R., Alam, Munazza K., Batalha, Natasha E., Lothringer, Joshua D., Adams Redai, Jea, Barat, Saugata, Brande, Jonathan, Damiano, Mario, Daylan, Tansu, Espinoza, Néstor, Flagg, Laura, Goyal, Jayesh M., Grant, David, Hu, Renyu, Inglis, Julie, Lee, Elspeth K. H., Mikal-Evans, Thomas, Ramos-Rosado, Lakeisha, Roy, Pierre-Alexis, Wallack, Nicole L., Batalha, Natalie M., Bean, Jacob L., Benneke, Björn, Berta-Thompson, Zachory K., Carter, Aarynn L., Changeat, Quentin, Colón, Knicole D., Crossfield, Ian J. M., Désert, Jean-Michel, Foreman-Mackey, Daniel, Gibson, Neale P., Kreidberg, Laura, Line, Michael R., López-Morales, Mercedes, Molaverdikhani, Karan, Moran, Sarah E., Morello, Giuseppe, Moses, Julianne I., Mukherjee, Sagnick, Schlawin, Everett, Sing, David K., Stevenson, Kevin B., Taylor, Jake, Aggarwal, Keshav, Ahrer, Eva-Maria, Allen, Natalie H., Barstow, Joanna K., Bell, Taylor J., Blecic, Jasmina, Casewell, Sarah L., Chubb, Katy L., Crouzet, Nicolas, Cubillos, Patricio E., Decin, Leen, Feinstein, Adina D., Fortney, Joanthan J., Harrington, Joseph, Heng, Kevin, Iro, Nicolas, Kempton, Eliza M.-R., Kirk, James, Knutson, Heather A., Krick, Jessica, Leconte, Jérémy, Lendl, Monika, MacDonald, Ryan J., Mancini, Luigi, Mansfield, Megan, May, Erin M., Mayne, Nathan J., Miguel, Yamila, Nikolov, Nikolay K., Ohno, Kazumasa, Palle, Enric, Parmentier, Vivien, Petit dit de la Roche, Dominique J. M., Piaulet, Caroline, Powell, Diana, Rackham, Benjamin V., Redfield, Seth, Rogers, Laura K., Rustamkulov, Zafar, Tan, Xianyu, Tremblin, P., Tsai, Shang-Min, Turner, Jake D., de Val-Borro, Miguel, Venot, Olivia, Welbanks, Luis, Wheatley, Peter J., and Zhang, Xi
- Abstract
Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems1,2. Access to the chemical inventory of an exoplanet requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based3–5and high-resolution ground-based6–8facilities. Here we report the medium-resolution (R≈ 600) transmission spectrum of an exoplanet atmosphere between 3 and 5 μm covering several absorption features for the Saturn-mass exoplanet WASP-39b (ref. 9), obtained with the Near Infrared Spectrograph (NIRSpec) G395H grating of JWST. Our observations achieve 1.46 times photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO2(28.5σ) and H2O (21.5σ), and identify SO2as the source of absorption at 4.1 μm (4.8σ). Best-fit atmospheric models range between 3 and 10 times solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterizing the chemistry in exoplanet atmospheres and showcase NIRSpec G395H as an excellent mode for time-series observations over this critical wavelength range10.
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- 2023
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5. High precision ground-based CCD photometry from the Next Generation Transit Survey
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Holland, Andrew D., Beletic, James, Bayliss, Daniel, O'Brien, Sean M., Bryant, Edward, Wheatley, Peter, West, Richard, McCormac, James, Chote, Paul, Gill, Sam, Anderson, David R., Wise, Adam, Juvan-Beaulieu, Ines, Coates, Colin, Gillen, Edward, Smith, Alexis M. S., Jenkins, James S., Moyano, Maximiliano, Alves, Douglas R., Burleigh, Matthew R., Goad, Michael R., Casewell, Sarah L., Acton, Jack, Tilbrook, Rosanna L., Henderson, Beth A., and Kendall, Alicia
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- 2022
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6. A remnant planetary core in the hot-Neptune desert
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Armstrong, David J., Lopez, Théo A., Adibekyan, Vardan, Booth, Richard A., Bryant, Edward M., Collins, Karen A., Deleuil, Magali, Emsenhuber, Alexandre, Huang, Chelsea X., King, George W., Lillo-Box, Jorge, Lissauer, Jack J., Matthews, Elisabeth, Mousis, Olivier, Nielsen, Louise D., Osborn, Hugh, Otegi, Jon, Santos, Nuno C., Sousa, Sérgio G., Stassun, Keivan G., Veras, Dimitri, Ziegler, Carl, Acton, Jack S., Almenara, Jose M., Anderson, David R., Barrado, David, Barros, Susana C. C., Bayliss, Daniel, Belardi, Claudia, Bouchy, Francois, Briceño, César, Brogi, Matteo, Brown, David J. A., Burleigh, Matthew R., Casewell, Sarah L., Chaushev, Alexander, Ciardi, David R., Collins, Kevin I., Colón, Knicole D., Cooke, Benjamin F., Crossfield, Ian J. M., Díaz, Rodrigo F., Mena, Elisa Delgado, Demangeon, Olivier D. S., Dorn, Caroline, Dumusque, Xavier, Eigmüller, Philipp, Fausnaugh, Michael, Figueira, Pedro, Gan, Tianjun, Gandhi, Siddharth, Gill, Samuel, Gonzales, Erica J., Goad, Michael R., Günther, Maximilian N., Helled, Ravit, Hojjatpanah, Saeed, Howell, Steve B., Jackman, James, Jenkins, James S., Jenkins, Jon M., Jensen, Eric L. N., Kennedy, Grant M., Latham, David W., Law, Nicholas, Lendl, Monika, Lozovsky, Michael, Mann, Andrew W., Moyano, Maximiliano, McCormac, James, Meru, Farzana, Mordasini, Christoph, Osborn, Ares, Pollacco, Don, Queloz, Didier, Raynard, Liam, Ricker, George R., Rowden, Pamela, Santerne, Alexandre, Schlieder, Joshua E., Seager, Sara, Sha, Lizhou, Tan, Thiam-Guan, Tilbrook, Rosanna H., Ting, Eric, Udry, Stéphane, Vanderspek, Roland, Watson, Christopher A., West, Richard G., Wilson, Paul A., Winn, Joshua N., Wheatley, Peter, Villasenor, Jesus Noel, Vines, Jose I., and Zhan, Zhuchang
- Abstract
The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune ‘desert’1,2(a region in mass–radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b3, which is thought to have an unusually massive core, and recent discoveries such as LTT9779b4and NGTS-4b5, on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune’s but an anomalously large mass of 39.1−2.6+2.7Earth masses and a density of 5.2−0.8+0.7grams per cubic centimetre, similar to Earth’s. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than 3.9−0.9+0.8per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation6. Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.
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- 2020
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7. The Transiting Exoplanet Community Early Release Science Program for JWST
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Bean, Jacob L., Stevenson, Kevin B., Batalha, Natalie M., Berta-Thompson, Zachory, Kreidberg, Laura, Crouzet, Nicolas, Benneke, Björn, Line, Michael R., Sing, David K., Wakeford, Hannah R., Knutson, Heather A., Kempton, Eliza M.-R., Désert, Jean-Michel, Crossfield, Ian, Batalha, Natasha E., Wit, Julien de, Parmentier, Vivien, Harrington, Joseph, Moses, Julianne I., Lopez-Morales, Mercedes, Alam, Munazza K., Blecic, Jasmina, Bruno, Giovanni, Carter, Aarynn L., Chapman, John W., Decin, Leen, Dragomir, Diana, Evans, Thomas M., Fortney, Jonathan J., Fraine, Jonathan D., Gao, Peter, Muñoz, Antonio García, Gibson, Neale P., Goyal, Jayesh M., Heng, Kevin, Hu, Renyu, Kendrew, Sarah, Kilpatrick, Brian M., Krick, Jessica, Lagage, Pierre-Olivier, Lendl, Monika, Louden, Tom, Madhusudhan, Nikku, Mandell, Avi M., Mansfield, Megan, May, Erin M., Morello, Giuseppe, Morley, Caroline V., Nikolov, Nikolay, Redfield, Seth, Roberts, Jessica E., Schlawin, Everett, Spake, Jessica J., Todorov, Kamen O., Tsiaras, Angelos, Venot, Olivia, Waalkes, William C., Wheatley, Peter J., Zellem, Robert T., Angerhausen, Daniel, Barrado, David, Carone, Ludmila, Casewell, Sarah L., Cubillos, Patricio E., Damiano, Mario, Val-Borro, Miguel de, Drummond, Benjamin, Edwards, Billy, Endl, Michael, Espinoza, Nestor, France, Kevin, Gizis, John E., Greene, Thomas P., Henning, Thomas K., Hong, Yucian, Ingalls, James G., Iro, Nicolas, Irwin, Patrick G. J., Kataria, Tiffany, Lahuis, Fred, Leconte, Jérémy, Lillo-Box, Jorge, Lines, Stefan, Lothringer, Joshua D., Mancini, Luigi, Marchis, Franck, Mayne, Nathan, Palle, Enric, Rauscher, Emily, Roudier, Gaël, Shkolnik, Evgenya L., Southworth, John, Swain, Mark R., Taylor, Jake, Teske, Johanna, Tinetti, Giovanna, Tremblin, Pascal, Tucker, Gregory S., Boekel, Roy van, Waldmann, Ingo P., Weaver, Ian C., and Zingales, Tiziano
- Abstract
The James Webb Space Telescope(JWST) presents the opportunity to transform our understanding of planets and the origins of life by revealing the atmospheric compositions, structures, and dynamics of transiting exoplanets in unprecedented detail. However, the high-precision, timeseries observations required for such investigations have unique technical challenges, and prior experience with Hubble, Spitzer, and other facilities indicates that there will be a steep learning curve when JWSTbecomes operational. In this paper, we describe the science objectives and detailed plans of the Transiting Exoplanet Community Early Release Science (ERS) Program, which is a recently approved program for JWSTobservations early in Cycle 1. We also describe the simulations used to establish the program. The goal of this project, for which the obtained data will have no exclusive access period, is to accelerate the acquisition and diffusion of technical expertise for transiting exoplanet observations with JWST, while also providing a compelling set of representative data sets that will enable immediate scientific breakthroughs. The Transiting Exoplanet Community ERS Program will exercise the timeseries modes of all four JWSTinstruments that have been identified as the consensus highest priorities, observe the full suite of transiting planet characterization geometries (transits, eclipses, and phase curves), and target planets with host stars that span an illustrative range of brightnesses. The observations in this program were defined through an inclusive and transparent process that had participation from JWSTinstrument experts and international leaders in transiting exoplanet studies. The targets have been vetted with previous measurements, will be observable early in the mission, and have exceptional scientific merit. Community engagement in the project will be centered on a two-phase Data Challenge that culminates with the delivery of planetary spectra, timeseries instrument performance reports, and open-source data analysis toolkits in time to inform the agenda for Cycle 2 of the JWSTmission.
- Published
- 2018
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