Search for flares and associated CMEs on late-type main-sequence stars in optical SDSS spectra Florian Koller, Martin Leitzinger, Manuela Temmer, Petra Odert, Paul G. Beck and Astrid Veronig A&A, 646 (2021) A34 Published online: 02 February 2021 DOI: 10.1051/0004-6361/202039003