Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?

• DOI: 10.48550/arxiv.2401.01465
• Publication Date: 2024-01-01
• Authors: Quentin Changeat; J. W. Skinner; James Y‐K. Cho; Joonas Nättilä; I. Waldmann; A. F. Al-Refaie; Achrène Dyrek; Billy Edwards; T. M. Evans; Max Joshua; Giuseppe Morello; Nour Skaf; Angelos Tsiaras; Olivia Vénot; Kai Hou Yip
• Keywords: Hot Jupiter; Atmosphere of Jupiter; Solar eclipse

We present a comprehensive analysis of the Hubble Space Telescope observations atmosphere WASP-121 b, ultra-hot Jupiter. After reducing transit, eclipse, and phase-curve with uniform methodology addressing biases from instrument systematics, sophisticated atmospheric retrievals are used to extract robust constraints on thermal structure, chemistry, cloud properties atmosphere. Our shows that consistent strong inversion beginning at ~0.1 bar dayside, solar subsolar metallicity Z (i.e., -0.77 < log(Z) 0.05), super-solar C/O ratio 0.59 0.87). More importantly, utilizing high signal-to-noise repeated planet, we identify following unambiguous time-varying signals in data: i) shift putative hotspot offset between two phase-curves ii) varying spectral signatures transits eclipses. By simulating global dynamics b high-resolution, show identified quasi-periodic weather patterns, hence variability, level probed by (~5% ~10%) change timescale ~5 planet days; simulations, patterns arise formation movement storms fronts, causing hot (as well as cold) patches deform, separate, mix time.