Knowledge Bank

The unassigned red-degraded bands near 5450 {\AA} are identified as the strongest sequence of the green bands of the $BO2$ molecule. The unassigned violet-degraded bands near 5800 {\AA} have been studied under a variety of conditions. They were freest of overlapping impurity bands when obtained from a solid mixture, $SiO2-KBF4$, in an electrodeless discharge tube. It has been possible to obtain the spectrum in the absence of silicon but never without oxygen, fluorine and boron simultaneously present. The assignment of the correct number of atoms of each type to the emitting molecule will be discussed.