Vibration-rotation parameters for high-temperature silicon monoxide from sunspot spectra

Absorption features from vibrational transitions of silicon monoxide have been observed in sunspot umbrae between 1070 and 1225 cm^?1 using the Fourier transform spectrometer (FTS) at the McMath Solar Telescope of the National Solar Observatory, located at Kitt Peak. Sunspots are a source of high-temperature spectra not easily obtained in the laboratory. Measurements were made of 937 ²⁸SiO, ²⁹SiO, and ³⁰SiO fundamental and hot band transitions in the umbral spectrum extending to v = 10 and J = 80. All three isotopic species were treated together to derive 10 Dunham rotation-vibration coefficients.