Infrared spectroscopy of Mira variables. II - R Leonis, the H2O vibration-rotation bands

Abstract

Stellar water bands in high-resolution IR spectra in the 4000-6700 kayser region of the bright Mira variable R Leonis are described. The water spectrum originates in two layers, one near the boundary layers of the photosphere and the other in a cooler overlying region. The water spectrum layers are identified with the two CO and OH line-forming regions described by Hinkle (1978). An examination of characteristics of these regions provides support for a pulsation-shock model for Mira variables. An approximate column density of water molecules through the entire R Leo atmosphere is derived.