An ultraviolet system of Na2 at 2700 Å

The spectrum of Na2 from 2600 A to 2750 A has been recorded in absorption in the second order of a 3.4 m Ebert spectrograph with a reciprocal dispersion of 2.6 A/mm. The vibrational structure appears to the higher-energy side of theE-X system extending to about 2600 A. This system is namedF-X system. The vibrational analysis is performed and the molecular constants are evaluated.