Abstract Title: * Spectral observations of the symbiotic binary AG Peg during its 2015 eruption Authors: * M. Tomova, N. Tomov, R. Zamanov Institution: * IA and NAO, BAS poster Abstract Text: * The symbiotic system AG Peg considered not long ago as a prototype of symbiotic novae, underwent an optical eruption in 2015 and its behaviour raised the question about the evolutionary status of its accreting compact object. Based on high resolution data, taken with the 2m telescope of Bulgarian National Astronomical Observatory we analysed some optical spectral lines - typical indicators of loss of mass. The results of our analysis shed some light on the nature of the outburst and on its base - on the evolutionary status of the accreting compact object.