Knowledge Bank

The absorption spectrum of $N2$ has been photographed with a 6.5 m vacuum spectrograph in second order and rotational analysis has been performed for the bands belonging to two systems, $b\leftarrow X$ and $i\leftarrow X1$. The rotational constants obtained for five levels in the i-state are found to be identical with corresponding levels of the b-state. The constants in the lower state of the i-bands are $B""=1.9722cm-1$ and $D""=5.3\times 10-6cm-1$, in excellent agreement with those of the $v=1$ of the ground state. A newly-observed diffuse band at $990\backslash AA$ will be discussed in connection with a diffuse band at $1010\backslash AA$ which has been attributed to an $a""\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g+\leftarrow X1\Sigma g+$ $transition.2$