A new analysis of the OH radical spectrum from solar infrared observations

The solar spectrum offered the opportunity to discover OH lines with high rotational quantum numbers, which do not appear on laboratory spectra. On solar absorption spectra, we have identified about 580 lines, among which about 400 were observed for the first time. They belong to pure rotational transitions in the ground state (upsilon = 0 --> 3; J(max)'' = 48.5), as well as to the (1-0), (2-1), and (3-2) vibration-rotation bands (J(max)'' = 32.5). Previous pure rotation, vibration-rotation, and Lambda-doubling data sets related to the upsilon = 0 up to 3 levels were fitted simultaneously together with this new set of data in order to obtain a very complete and accurate set of molecular constants for the X(2) Pi ground state. (C)1995 Academic Press, Inc.