Résumé : Fourier-transform intracavity laser absorption spectroscopy allowed five 12C13CH2Σ+- Σ+ bands, all from the ground state, to be identified in the 0.83 μm range. Their rotational analysis was performed and rotational constants are provided. Three of these bands, with origins at 11616.9684(18), 11737.2356(14), and 11761.0322(23) cm-1, have never been reported before. Their upper states are assigned to V1V2V 3v4l4v5l5 = 1302 020, 130113-1, and 22011 1-1, respectively. © 2004 Elsevier Inc. All rights reserved.