Eleven emission bands have been rotationally analyzed in the 3000-2500
Angstrom spectral region and attributed as being due to transitions f
rom the (U) over tilde electronic state to vibronic levels of the (X)
over tilde(2) Sigma(+) ground state of C2H. Two new vibronic levels of
the (U) over tilde state have been identified and a new vibronic leve
l at 740 cm(-1) has been tentatively attributed to the 2 nu(2)('') lev
el of the ground state. (C) 1995 Academic Press, Inc.