A digital imaging multi-slit spectrograph for measurement of line-of-sightvelocities on the Sun

A multi-slit digital imaging spectrograph has been installed at Udaipur Sol ar Observatory, Udaipur (India) to measure the line-of-sight velocities in Ha associated with the mass motions of the dynamic phenomena on the solar s urface viz. solar flares, eruptive prominences and surges. This spectrograp h is being used in conjunction with a 15 cm aperture Coude telescope to obt ain the Ha spectra at a high rate of a specific region of interest on the S un. In this paper, we describe the principal features of this instrument an d the data acquisition method. We also present spectral observations of a s urge and a quiescent prominence recorded using this instrument.