TransitFit: combined multi-instrument exoplanet transit fitting for JWST, HST, and ground-based transmission spectroscopy studies
Issued Date
2024-01-01
Resource Type
ISSN
00358711
eISSN
13652966
Scopus ID
2-s2.0-85179742423
Journal Title
Monthly Notices of the Royal Astronomical Society
Volume
527
Issue
3
Start Page
4936
End Page
4954
Rights Holder(s)
SCOPUS
Bibliographic Citation
Monthly Notices of the Royal Astronomical Society Vol.527 No.3 (2024) , 4936-4954
Suggested Citation
Hayes J.J.C., Priyadarshi A., Kerins E., Awiphan S., McDonald I., A-Thano N., Morgan J.S., Humpage A., Charles S., Wright M., Joshi Y.C., Jiang I.G., Inyanya T., Padjaroen T., Munsaket P., Chuanraksasat P., Komonjinda S., Kittara P., Dhillon V.S., Marsh T.R., Reichart D.E., Poshyachinda S. TransitFit: combined multi-instrument exoplanet transit fitting for JWST, HST, and ground-based transmission spectroscopy studies. Monthly Notices of the Royal Astronomical Society Vol.527 No.3 (2024) , 4936-4954. 4954. doi:10.1093/mnras/stad3353 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/96016
Title
TransitFit: combined multi-instrument exoplanet transit fitting for JWST, HST, and ground-based transmission spectroscopy studies
Author's Affiliation
National Astronomical Research Institute of Thailand
Faculty of Science, Engineering and Medicine
Aryabhatta Research Institute of Observational Sciences
Suranaree University of Technology
The University of North Carolina at Chapel Hill
National Tsing Hua University
National University of Singapore
Mahidol University
The Open University
Instituto Astrofisico de Canarias
The University of Manchester
The University of Sheffield
Chiang Mai University
Yupparaj Wittayalai School
Faculty of Science, Engineering and Medicine
Aryabhatta Research Institute of Observational Sciences
Suranaree University of Technology
The University of North Carolina at Chapel Hill
National Tsing Hua University
National University of Singapore
Mahidol University
The Open University
Instituto Astrofisico de Canarias
The University of Manchester
The University of Sheffield
Chiang Mai University
Yupparaj Wittayalai School
Corresponding Author(s)
Other Contributor(s)
Abstract
We present transitfit1, a package designed to fit exoplanetary transit light curves. transitfit offers multi-epoch, multi-wavelength fitting of multi-telescope transit data. transitfit allows per-telescope detrending to be performed simultaneously with transit parameter fitting, including custom detrending. Host limb darkening can be fitted using prior conditioning from stellar atmosphere models. We demonstrate transitfit in a number of contexts. We model multi-telescope broad-band optical data from the ground-based SPEARNET survey of the low-density hot-Neptune WASP-127b and compare results to a previously published higher spectral resolution GTC/OSIRIS transmission spectrum. Using transitfit, we fit 26 transit epochs by TESS to recover improved ephemeris of the hot-Jupiter WASP-91b and a transit depth determined to a precision of 111 ppm. We use transitfit to conduct an investigation into the contested presence of TTV signatures in WASP-126b using 180 transits observed by TESS, concluding that there is no statistically significant evidence for such signatures from observations spanning 27 TESS sectors. We fit HST observations of WASP-43 b, demonstrating how transitfit can use custom detrending algorithms to remove complex baseline systematics. Lastly, we present a transmission spectrum of the atmosphere of WASP-96b constructed from simultaneous fitting of JWST NIRISS Early Release Observations and archive HST WFC3 transit data. The transmission spectrum shows generally good correspondence between spectral features present in both data sets, despite very different detrending requirements.