Four electronic transition systems, namely, the [12.7]3Π2 – [0.1]3Δ3, the [13.5]3Φ3 – [0.9]3Δ2, the [13.9]3Φ4 – [0.1]3Δ3, and the [13.9]3Π1 – [0.9]3Δ2 transitions of the ruthenium monocarbide molecule (RuC) were recorded and analyzed using laser vaporization/reaction supersonic free jet expansion and high resolution laser induced fluorescence spectroscopy. New vibrational bands of these transitions were observed and analyzed. Some of the observed bands show resolved hyperfine structure, which is caused principally by the unpaired 5sσ electron interacting with large magnetic moment of the 99Ru and 101Ru nuclei with spin I=5/2. The hyperfine width decreases rapidly as J increases suggesting that the hyperfine structure conforms to the Hund’s case aβ coupling scheme. Accurate molecular constants for the seven RuC isotopic molecules were obtained and the hyperfine constants for the [0.1]3Δ3, [12.7]3Π2 and [13.9]3Φ4 states of both 99RuC and 101RuC isotopes were also determined.