TY - JOUR
T1 - Colorado Ultraviolet Transit Experiment Near-ultraviolet Transmission Spectroscopy of the Ultrahot Jupiter KELT-9b
AU - Egan, Arika
AU - France, Kevin
AU - Sreejith, Aickara Gopinathan
AU - Fossati, Luca
AU - Koskinen, Tommi
AU - Fleming, Brian
AU - Nell, Nicholas
AU - Suresh, Ambily
AU - Cauley, P. Wilson
AU - Desert, Jean Michel
AU - Petit, Pascal
AU - Vidotto, Aline A.
N1 - Publisher Copyright:
© 2024. The Author(s). Published by the American Astronomical Society.
PY - 2024/9/1
Y1 - 2024/9/1
N2 - We present new near-ultraviolet (NUV, λ = 2479-3306 Å) transmission spectroscopy of KELT-9b, the hottest known exoplanet, obtained with the Colorado Ultraviolet Transit Experiment CubeSat. Two transits were observed on 2022 September 28th and September 29th, referred to as Visits 1 and 2 respectively. Using a combined transit and systematics model for each visit, the best-fit broadband NUV light curves are R p/R ⋆ = 0.136 − 0.0146 + 0.0125 for Visit 1 and R p/R ⋆ = 0.111 − 0.0190 + 0.0162 for Visit 2, appearing an average of 1.54× larger in the NUV than at optical wavelengths. While the systematics between the two visits vary considerably, the two broadband NUV light curves are consistent with each other. A transmission spectrum with 25 Å bins suggests a general trend of excess absorption in the NUV, consistent with expectations for ultrahot Jupiters. Although we see an extended atmosphere in the NUV, the reduced data lack the sensitivity to probe individual spectral lines.
AB - We present new near-ultraviolet (NUV, λ = 2479-3306 Å) transmission spectroscopy of KELT-9b, the hottest known exoplanet, obtained with the Colorado Ultraviolet Transit Experiment CubeSat. Two transits were observed on 2022 September 28th and September 29th, referred to as Visits 1 and 2 respectively. Using a combined transit and systematics model for each visit, the best-fit broadband NUV light curves are R p/R ⋆ = 0.136 − 0.0146 + 0.0125 for Visit 1 and R p/R ⋆ = 0.111 − 0.0190 + 0.0162 for Visit 2, appearing an average of 1.54× larger in the NUV than at optical wavelengths. While the systematics between the two visits vary considerably, the two broadband NUV light curves are consistent with each other. A transmission spectrum with 25 Å bins suggests a general trend of excess absorption in the NUV, consistent with expectations for ultrahot Jupiters. Although we see an extended atmosphere in the NUV, the reduced data lack the sensitivity to probe individual spectral lines.
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U2 - 10.3847/1538-3881/ad61e5
DO - 10.3847/1538-3881/ad61e5
M3 - Article
AN - SCOPUS:85200821646
SN - 0004-6256
VL - 168
JO - Astronomical Journal
JF - Astronomical Journal
IS - 3
M1 - 108
ER -