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Constraining Stellar Photospheres as an Essential Step for Transmission Spectroscopy of Small ExoplanetsTransiting exoplanets offer a unique opportunity to study the atmospheres of terrestrial worlds in other systems in the coming decade. By absorbing and scattering starlight, exoplanet atmospheres produce spectroscopic transit depth variations that allow us to probe their physical structures and chemical compositions. These same variations, however, can be introduced by the photospheric heterogeneity of the host star (i.e., the transit light source effect). Recent modeling efforts and increasingly precise observations are revealing that our understanding of transmission1spectra of the smallest transiting exoplanets will likely be limited by our knowledge of host star photospheres. Here we outline promising scientific opportunities for the next decade that can provide useful constraints on stellar photospheres and inform interpretations of transmission spectra of the smallest(R < 4R) exoplanets. We identify and discuss four primary opportunities: (1) refining stellar magnetic active region properties through exoplanet crossing events; (2) spectral decomposition of active exoplanet host stars; (3) joint retrievals of stellar photospheric and planetary atmospheric properties with studies of transmission spectra; and (4) continued visual transmission spectroscopy studies to complement longer-wavelength studies from JWST. In this context, we make four recommendations to the Astro2020 Decadal Survey Committee:(1) identify the transit light source (TLS) effect as a challenge to precise exoplanet transmission spectroscopy and an opportunity ripe for scientific advancement in the coming decade; (2) include characterization of host star photospheric heterogeneity as part of a comprehensive research strategy for studying transiting exoplanets; (3) support the construction of ground-based extremely large telescopes (ELTs); (4) support multi-disciplinary research teams that bring together the heliophysics, stellar physics, and exoplanet communities to further exploit transiting exoplanets as spatial probes of stellar photospheres; and (5) support visual transmission spectroscopy efforts as complements to longer-wavelength observational campaigns with JWST.
Document ID
20190032595
Acquisition Source
Goddard Space Flight Center
Document Type
Other
Authors
Rackham, Benjamin V.
(Arizona State Univ. Phoenix, AZ, United States)
Pinhas, Arazi
(University of Cambridge Cambridge, England, United Kingdom)
Apai, D´aniel
(University of Northern Arizona Flagstaff, AZ, United States)
Haywood, Rapha¨elle
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Cegla, Heather
(Geneva Observatory Sauverny, Switzerland)
Espinoza, N´estor
(Max-Planck-Institut für Aeronomie Heidelberg, Germany)
Teske, Johanna
(Carnegie Institution for Science Pasadena, CA, United States)
Gully-Santiago, Michael
(NASA Ames Research Center Moffett Field, CA, United States)
Rau, Gioia
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Morris, Brett M.
(Washington State Univ. Pullman, WA, United States)
Angerhausen, Daniel
(Bern Univ. Bern, Switzerland)
Wit, Julien de
(Massachusetts Institute of Technology (MIT) Cambridge, MA, United States)
Barclay, Thomas
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Carone, Ludmila
(Max-Planck-Institut für Aeronomie Heidelberg, Germany)
Cauley, P. Wilson
(Colorado Univ. Boulder, CO, United States)
Domagal-Goldman, Shawn
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Dong, Chuanfei
(Princeton Univ. Princeton, NJ, United States)
Dragomir, Diana
(Massachusetts Institute of Technology (MIT) Cambridge, MA, United States)
Giampapa, Mark S.
(National Solar Observatory Boulder, CO, United States)
Hasegawa, Yasuhiro
(Jet Propulsion Laboratory (JPL), California Institute of Technology (CalTech) Pasadena, CA, United States)
Hinkel, Natalie R.
(Southwest Research Inst. Boulder, CO, United States)
Hu, Renyu
(Jet Propulsion Laboratory (JPL), California Institute of Technology (CalTech) Pasadena, CA, United States)
Jord´an, Andr´es
(Pontifical Catholic Univ. of Chile Santiago, Chile)
Kitiashvili, Irina
(NASA Ames Research Center Moffett Field, CA, United States)
Kreidberg, Laura
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Lisse, Carey
(Johns Hopkins Univ. Baltimore, MD, United States)
Llama, Joe
(Lowell Observatory Flagstaff, AZ, United States)
L´opez-Morales, Mercedes
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Mennesson, Bertrand
(Jet Propulsion Laboratory (JPL), California Institute of Technology (CalTech) Pasadena, CA, United States)
Molaverdikhani, Karan
(Max-Planck-Institut für Aeronomie Heidelberg, Germany)
Osip, David J.
(Las Campanas Observatory La Serena, Chile)
Quintana, Elisa V.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
November 7, 2019
Publication Date
July 22, 2019
Subject Category
Instrumentation And Photography
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN71306
Funding Number(s)
CONTRACT_GRANT: 80GSFC17M0002
Distribution Limits
Public
Copyright
Public Use Permitted.
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