Spectroscopic observations of comet P/Brorsen-Metcalf in the 3500–7550 Å wavelength region

Abstract

The spectroscopic observations of comet P/Brorsen-Metcalf were made at the high-altitude station “Terskol” of the Main Astronomical Observatory of Ukraine in August 1989. The spectra were taken using the image intensifier “Topaz” with the UMK-91VM image tube as the basic unit. The spectra cover the wavelength region from 3500 to 7550 Å at resolution ranging from 1.8 to 7.7 Å. We carried out the identification of 329 spectral features in the P/Brorsen-Metcalf spectra. We found emissions of CN, C 2, 12C 13C, CH, C 3, NH 2, Na, O[I] neutrals, and N 2 +, OH +, CO +, CH +, CO 2 +, H 2O + ions in our spectra. We detected the transitions from the rotational levels up to J″ = 99 for the Δν = 0 C 2 sequence for the first time. We found five features which coincide with the wavelength of laboratory band heads for HCO, and three which coincide with the heads of the Swan “tail” bands as well.