On the search for BF, BH and BS molecular lines in sunspot spectra

A search has been carried out for the presence of rotational lines of boron containing diatomic molecules BF, BH and BS in the high resolution Fourier Transform Spectra of sunspots observed at the National Solar Observatory in Kitt Peak. The spectra were examined for a large number of rotational lines due to nine bands of BF, ten bands of BH and eight bands of BS in the range 9600-25,500 cm−1. The presence of the lines due to six bands of BF and five bands of BS is confirmed. However, the presence of BH is found to be questionable. Equivalent widths have been measured for well resolved lines of BF and BS and effective rotational temperatures have been estimated.