NICER views moderate, strong, and extreme photospheric expansion bursts from the ultracompact X-ray binary 4U 1820–30Wenhui Yu, Zhaosheng Li, Yongqi Lu, Yuanyue Pan, Xuejuan Yang, Yupeng Chen, Shu Zhang and Maurizio FalangaA&A, 683 (2024) A93DOI: https://doi.org/10.1051/0004-6361/202348195
