Pre-conditions for disc-generated FU Orionis outbursts

We examine the condition in which a protostellar disc must be set up in order to generate FU Orionis outbursts. We find that FU Orionis behaviour can be produced by perturbation of a low accretion rate disc around a normal T Tauri star. Suitable perturbations involve a substantial surface density enhancement and heating to $$\thicksim {10}^{4}\,\text{K}$$ of the inner disc.