The Near Ultraviolet Spectra of Comets P/Brorsen-Metcalf and Austin

We-report results of spectrophotometric observations of comets P/Brorsen-Metcalf and Austin from 3000 to 3600Å at a spectral resolution of about 1.8A. The strongest features are the OII (A-X) 0-0 and 1-1 bands, and the NH (A-X) 0-0 bands. We have clearly found, for the first time, the OII (A-X) 0-1 band. We verify the existence of, and quantitatively measure, the CN (B-X) 2-1 and 3-2 bands, We detect a feature at 3258Å that was first seen in uncalibrated spectra, and suggest identification as the NH singlet (c-a) 0-0 transition. We have also firmly identified the CO features at 3378, 3504, and 3512Å. This ion was reported as being present in the tail of Comet Hester (1948 I) by Swings and Page (1950). We propose identification of a weak feature at 3547Å as the fundamental transition of H2CO, which would make this the first optical cometary detection of this molecule which is very abundant in giant molecular clouds.