Photometric observations of emission line features of the coma of comet Kohoutek (1973f) were made with narrow band interference filters. The emission features observed were CN(3879 A°), C3(4057 A°), and C2(4732, 5165,5634 A°). The radial dependence of the emission was investigated by employing six diaphragms set concentrically about the brightest part of the comet's head.
The photometric observations were made at the Optical Research Facility and Observatory of NASA/Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. The observatory is located 13 miles Northeast of Washington, D.C. (longitude = 5h07m18s22, latitude = +39° 01′ 11.″48, altitude = 49 meters) and is operated by the Laboratory for Optical Astronomy of Goddard (GSFC).