2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/1838We report on a large X-ray flare from the Lindroos binary system HD 560 during a pointed ROSAT PSPC observation. Strong magnetic activity is expected for the late-type component (a G dwarf star and post-T Tauri Star candidate). The system is unresolved in the ROSAT image. Therefore, although not expected from a theoretical point of view, it can not be excluded that the flare has erupted on the primary, a late-B type star. We discuss the luminosity and temperature evolution comparing the quiescent and the flare state of HD 560, and present arguments for the G star as host of the flare.4 pages, 2 figures, accepted by A&AAstrophysicstext