Pre-main sequence solar type stars (aka T Tauri stars) accrete matter from a circumstellar disk. While there is little doubt that the accretion is mediated by a stellar magnetic field, the details of the accretion process and of the associated phenomena are, however, poorly understood.

  BP Tau is a well studied classical TTS, that is accreting matter at an average rate of around 3.0e-8 Msun/yr. This accretion is responsible for the observed UV, optical and near-infrared excess continuum emission. BP Tau is known to display photometric and spectroscopic variability in timescales ranging from around 30 minutes to a few days. These variations have been interpreted as the result of inhomogeneous accretion and rotational modulation.

  In this talk I will present results of an ongoing study that probes the shortest timescales (minutes) of variability in BP Tau and discuss how they help us to better understand TTS and hence the early history of the Sun.