A spectrographic study of the symbiotic system HEN 1761

This work presents the results of a spectroscopic study in the optical and near infrared region of the symbiotic star Hen 1761. Relative fluxes and radial velocities of emission and absorption lines are obtained on the basis of low, intermediate and high resolution spectra. Our observations show that this scarcely studied object underwent very important spectroscopic variations in the interval 1990-1995. The observed variations are quite similar to those of symbiotic stars where accretion events on a hot dwarf are responsible for an eruptive behavior. Some of the physical parameters of the system are derived. Based on observations taken at Complejo Astronómico El Leoncito (CASLEO), operated under an agreement between the Consejo Nacional de Investigaciones Cient\'{\i