The optical spectrum of R Coronae Borealis close to 2003 decline

Abstract

Two sets of high-resolution spectra of R CrB obtained during the 2003 light decline are described. The first set was obtained on the descending branch of the light curve when V ~12.0 and the second one in the recovery phase with V ~7.5. The usual sharp and broad emissions are described and the lines radial velocities measured. C2 Swan system (0,0) band was found to be in emission for the first set. The other C2 bands were in absorption. Few CN red system (5,1) band rotational lines and low excitation FeI lines were in absorption. A table with measured radial velocities of various spectral features is presented.