CN(B 2Σ+) is produced in a corona-excited supersonic expansion and its fluorescence spectrum is measured with a Fourier transform UV/VIS spectrometer. Rotational temperatures as low as 75 K and vibrational temperatures on the order of 2200 K are achieved in the expansion. Under some expansion conditions, rotational levels as high as K′ = 66 are observed. We report new D0 and γ0 values for the B-state based on an analysis of P-branch line positions and spin-rotation splittings. These values are: D0 = 0.6626 × 10−5 cm−1 and γ0 = 1.553 × 10−2 cm−1. The power and sensitivity of this technique for the study of the electronic spectroscopy of highly reactive molecules is discussed.