Observations of several new transitions of interstellar HCO

Four new transitions of the interstellar formyl radical, HCO have been detected. Five transitions are now known for interstellar HCO, and thus its identification is secure. The column density found by assuming NGC 2024 is an extended source is N subT(HCO) = (8.5 + or - 4.0) x 10 to the 12th/sq cm. This gives a fractional abundance (abundance relative to hydrogen) for NGC 2024 which agrees quite well with some theoretical predictions. Several unidentified lines were detected and are reported here. Tentative identification for some of the unidentified lines are suggested.