Two decades of optical variability of Small Magellanic Cloud high-mass X-ray binaries H. Treiber, G. Vasilopoulos, C. D. Bailyn, F. Haberl and A. Udalski A&A, 694 (2025) A43 Published online: 31 January 2025 DOI: 10.1051/0004-6361/202451132