Atmospheric characterization and tighter constraints on the orbital misalignment of WASP-94 A b with HARPS

Summary, in English

We present high spectral resolution observations of the hot Jupiter WASP-94 A b using the HARPS instrument on ESO’s 3.6-m telescope in La Silla, Chile. We probed for Na absorption in its atmosphere as well as constrained the previously reported misaligned retrograde orbit using the Rossiter–McLaughlin effect. Additionally, we undertook a combined atmospheric retrieval analysis with previously published low-resolution data. We confirm the retrograde orbit as well as constrain the orbital misalignment with our measurement of a projected spin-orbit obliquity of λ = 123.0 ± 3.0°. We find a tentative detection of Na absorption in the atmosphere of WASP-94 A b, independent of the treatment of the Rossiter–McLaughlin effect in our analysis (3.6σ and 4.4σ). We combine our HARPS high-resolution data with low-resolution data from the literature and find that while the posterior distribution of the Na abundance results in a tighter constraint than using a single data set, the detection significance does not improve (3.2σ), which we attribute to degeneracies between the low- and high-resolution data.

• Author: E Ahrer; J V Seidel; L Doyle; S Gandhi; B Prinoth; H M Cegla; C H McDonald; N Astudillo-Defru; E Ayache; R Nealon; Dimitri Veras; P J Wheatley; D Ehrenreich
• Department/s: Astrophysics
• Publishing year: 2024-04-25
• Language: English
• Pages: 2749-2759
• Publication/Series: Monthly Notices of the Royal Astronomical Society
• Volume: 530
• Issue: 3
• Links: http://dx.doi.org/10.1093/mnras/stae1000
• Document type: Journal article
• Publisher: Oxford University Press
• Topic: Astronomy, Astrophysics and Cosmology
• Status: Published
• ISBN/ISSN/Other: ISSN: 1365-2966