FUV flux of nearby exoplanet host stars in the Ariel target list
- Author(s)
- Sudeshna Boro Saikia, Stefano Bellotti, Andrea Bocchieri, Sarah Casewell, Billy Edwards, Luca Fossati, A. García Muñoz, Manuel Güdel, Franz Kerschbaum, Kristina Kislyakova, Theresa Lueftinger, Antonio Maggio, Yamila Miguel, Lorenzo. V. Mugnai, Ignazio Pillitteri, Donna Rodgers-Lee, Simon Schleich, Giovanna Tinetti, Gwenael Van Looveren, Olivia Venot, Krisztián Vida, A. A. Vidotto, Jiri Zak
- Abstract
Stellar extreme ultraviolet (EUV) radiation drives atmospheric photochemistry and loss in orbiting planets. Hence, knowledge of EUV fluxes of exoplanet host stars is essential in the interpretation of exoplanet transmission spectra, as shown by the recent discovery of SO2 in gaseous exoplanets observed by JWST. In the absence of an instrument observing in the EUV wavelength and the known problem of instellar absorption in this wavelength range, far ultraviolet (FUV) flux acts as a proxy for the EUV flux.
We aim to estimate the EUV flux of a volume-limited sample of Ariel target stars within 100 pc from FUV spectra taken by HST/COS in the G140L grating. Planned to be launched in five years (2029), the Ariel mission will carry out transit and eclipse spectroscopy of ~1000 exoplanets and determine their atmospheric chemical abundances. The Ariel target list contains 154 exoplanet host stars within 100 pc out of which 17 have prior FUV data. We ask for a snapshot survey of the remaining 137 Ariel targets for which no FUV spectra exist.
Our sample is divided into three groups, with the top priority given to common Ariel and JWST targets, followed by high-priority and medium-to-low priority Ariel targets. The estimated EUV fluxes will be used as input in atmospheric photochemical models and in the target refinement of Ariel. The results will also be useful to the community in future JWST proposal preparations. Since snapshot programmes do not guarantee observations of all 137 targets, a completion rate of 13% (17 new stellar spectra) will double the current archival sample. This will enable us to perform a robust statistical analysis on the combined new and archival data.- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Institut de Recherche en Astrophysique et Planetolgie, Sapienza University of Rome, University of Leicester, SRON Netherlands Institute for Space Research , Österreichische Akademie der Wissenschaften (ÖAW), Université Paris Saclay, Science and Operations Department - Science Division (SCI-SC), INAF Osservatorio Astronomico di Palermo, Leiden University, Dublin Institute for Advanced Studies, University College London, Université Paris VII - Paris-Diderot, HUN-REN Hungarian Research Network, European Southern Observatory (Germany)
- Publication date
- 07-2024
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/92c7d71a-004b-4285-9d8a-6f736fa74be7