Knowledge Bank

The vibration-rotation OH spectrum emitted by an acetylene oxygen flame has been measured between 2700 and $11000cm-1$ with a high resolution Fourier Spectrometer. The main interferences in the spectra are due to water vapor absorption and emission necessarily mixed with OH in the source. Nevertheless, line positions to high J values (more than 20 for some P branches) of the 1-0, 2-1 bands of the $\Delta v=1$ sequence, 2-0, 3-1, 4-2, 5-3 of $\Delta v$ = 2 and 3-0, 4-1, 5-2 bands of $\Delta v=3$ are reported. Molecular constants for each band were derived by using a computer program described by Albritton, et al. Ground state molecular constants of OH were derived from a least squares fit to these data, weighted according to their estimated uncertainties. Uncertainties in the molecular constants derived from these data are considerably improved relative to the previously available constants. Predicted positions of some unobserved bands of OH have been determined from these new constants for the purpose of aiding stellar atmospheric studies.