The methylidyne radical (CH) was the
astromolecule conclusively to be identified. CH was detected via
electronic transitions in both the interstellar medium and in comets. The interstellar reports included papers by
Swings & Rosenfeld
in 1937, followed by
McKellar in 1940, and
Adams in 1941.
A radio detection by
Rydbeck et al.
followed in 1974. The initial cometary detections were reported by
Nicolet in 1938 and
Dufay in 1940.
April 2007 - A new study by
Sheffer & Federman reports the
identification of half a dozen lines for CH in the UV region.
The CH radical is very reactive. It can be produced in
hydrocarbon combustion and can
even attack the very stable N2 molecule.