We present preliminary results on a study based on contemporaneous photometric and spectroscopic observations of the young K0-1V star SAO 51891. We find that SAO 51891, a possible member of the Local Association, shows emission cores in the CaII H&K and fillings in the Halpha and CaII Infra-Red Triplet (IRT) lines. Moreover, we detect absorption lines of HeI-D3 and LiI and measure a v sini of 19 km/s. A clear rotational modulation of both the light and the photospheric temperature, due to photospheric spots, has been detected. The net Halpha chromospheric emission does not show any detectable variation, while the CaII IRT emission displays a fair modulation.