PS1-10jh - a tidal disruption event with an extremely low disc temperature.

The cooler than expected optical-UV transient PS1-10jh detected by the Pan-STARRS1 survey is probably related to a tidal disruption event in which a He-rich stellar core remnant is implied. The evolution of bound debris during the disc-phase is studied by solving the hydrodynamic equations. The model provides a good fit either of the raising part of the light curve in the bands g_P1, r_P1 and i_P1 or in the early decay. The parameters characterizing this optimized model are the mass of the central black hole, i.e. 6.3 × 10⁶ M_⊙, and the critical Reynolds number R = 10^4 that fixes the viscosity and the accretion time-scale. Such a high value of R explains the low disc temperature and the consequent absence of X-ray emission. The predicted bolometric peak luminosity is about 10⁴⁵ erg s^{- 1} and the predicted total radiated energy is about E_rad = 2.67 × 10⁵¹ erg.