Detection of the 610 micron /492 GHz/ line of interstellar atomic carbon

The ground-state transition of neutral atomic carbon, /sup 3/P/sub 1//sup en-dash3/P/sub 0/, has been detected in the interstallar medium at the frequency of 492.162 GHz determined in the laboratory by Saykally and Evenson. The observations were made fom the NASA Kuiper Airborne Observatory using an InSb heterodyne bolometer receiver. The line was detected as strong emission from eight molecular clouds and apparently provides a widely useful probe of the interstellar medium.