Uranus’ hydrogen upper atmosphere: Insights from pre- and post-equinox HST Lyman-α images Sushen Joshi, Lorenz Roth, Randy Gladstone, Nickolay Ivchenko, Wayne Pryor and Laurent Lamy A&A, 693 (2025) A231 Published online: 21 January 2025 DOI: 10.1051/0004-6361/202450719