  Results of high-cadence multi-colour observations of 121 pre-main sequence
stars available from the northern hemisphere are presented. The aim of this
survey was to detect transit-like signatures caused by occultation of these
young stars and their accretion-induced hot spots by close-in planets and/or
dusty clumps. Although none planetary transits were detected, our data allow to
determine rotational periods for some T Tauri stars, characterise accretion
processes operating in classical T Tauri-type stars in time scales ranging from
a few minutes to days, as well as the large-scale dips caused by dusty warped
discs.
