We present near-infrared spectroscopic monitoring of the carbon star RW LMi (2019–2024), revealing phase-dependent variations in molecular band depths and their anomalous behavior. Observations were obtained with the ASTRONIRCAM spectrograph on the 2. 5-m telescope at the Caucasian Mountain Observatory. The detection of molecular bands across 1. 1–2. 3 m despite a dense, hot circumstellar dust envelope suggests their formation occurs within the envelope rather than in the stellar atmosphere.
Vakhonin et al. (Mon,) studied this question.