Flares in open clusters with K2 - II. Pleiades, Hyades, Praesepe, Ruprecht 147, and M 67 Ekaterina Ilin, Sarah J. Schmidt, Katja Poppenhäger, James R. A. Davenport, Martti H. Kristiansen and Mark Omohundro A&A, 645 (2021) A42 Published online: 07 January 2021 DOI: 10.1051/0004-6361/202039198