The Terminator Region Atmosphere of the hot Jupiter WASP-77Ab with ESPRESSO/VLT observations

Fuente: arXiv
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Main Authors: Jiang, Zewen, Wang, Wei, Chen, Guo, Shi, Yaqing, Zhai, Meng, Rojo, Patricio, Liu, Yujuan, Zhao, Gang
Format: Preprint
Published: 2024
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author Jiang, Zewen
Wang, Wei
Chen, Guo
Shi, Yaqing
Zhai, Meng
Rojo, Patricio
Liu, Yujuan
Zhao, Gang
author_facet Jiang, Zewen
Wang, Wei
Chen, Guo
Shi, Yaqing
Zhai, Meng
Rojo, Patricio
Liu, Yujuan
Zhao, Gang
contents Atmospheric studies are essential for elucidating the formation history, evolutionary processes, and atmospheric dynamics of exoplanets. High-resolution transmission spectroscopy offers the advantage of detecting subtle variations in stellar spectral profiles, thereby enabling the identification of the sources of observed signals. In this study, we present the transmission spectra of the exoplanet WASP-77Ab, a hot Jupiter with a 1.36-day orbital period around a G8 host star with $V=11.29$ mag. These observations were conducted using the high-resolution spectrograph ESPRESSO at the Very Large Telescope over three transit events. We analyze the Rossiter-McLaughlin effect for WASP-77A and determine a projected spin-orbit angle of ${λ= 16.131^{\circ}}^{+2.106}_{-2.324}$, indicating that the planet's orbit is nearly aligned. Following the generation of transmission spectra for the three nights, we model and correct for center-to-limb variation and the Rossiter-McLaughlin effects. In the residual transmission spectra, we detect H$α$, H$β$ and CaII H with a significance exceeding 3.5$σ$. After applying 0.1-0.5 Å masks to the cores of these lines to mitigate stellar contamination, all them still shows visible absorptions although not significant, suggesting at least partial planet contribution to them. Therefore, we are yet unable to confirm or reject the planetary origin of these spectral signals based on the current data set. Further investigation of WASP-77Ab's atmosphere, particularly in areas beyond the terminator region, is essential to illuminate the planet's two-dimensional atmospheric structure.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02095
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The Terminator Region Atmosphere of the hot Jupiter WASP-77Ab with ESPRESSO/VLT observations
Jiang, Zewen
Wang, Wei
Chen, Guo
Shi, Yaqing
Zhai, Meng
Rojo, Patricio
Liu, Yujuan
Zhao, Gang
Earth and Planetary Astrophysics
Atmospheric studies are essential for elucidating the formation history, evolutionary processes, and atmospheric dynamics of exoplanets. High-resolution transmission spectroscopy offers the advantage of detecting subtle variations in stellar spectral profiles, thereby enabling the identification of the sources of observed signals. In this study, we present the transmission spectra of the exoplanet WASP-77Ab, a hot Jupiter with a 1.36-day orbital period around a G8 host star with $V=11.29$ mag. These observations were conducted using the high-resolution spectrograph ESPRESSO at the Very Large Telescope over three transit events. We analyze the Rossiter-McLaughlin effect for WASP-77A and determine a projected spin-orbit angle of ${λ= 16.131^{\circ}}^{+2.106}_{-2.324}$, indicating that the planet's orbit is nearly aligned. Following the generation of transmission spectra for the three nights, we model and correct for center-to-limb variation and the Rossiter-McLaughlin effects. In the residual transmission spectra, we detect H$α$, H$β$ and CaII H with a significance exceeding 3.5$σ$. After applying 0.1-0.5 Å masks to the cores of these lines to mitigate stellar contamination, all them still shows visible absorptions although not significant, suggesting at least partial planet contribution to them. Therefore, we are yet unable to confirm or reject the planetary origin of these spectral signals based on the current data set. Further investigation of WASP-77Ab's atmosphere, particularly in areas beyond the terminator region, is essential to illuminate the planet's two-dimensional atmospheric structure.
title The Terminator Region Atmosphere of the hot Jupiter WASP-77Ab with ESPRESSO/VLT observations
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2412.02095