The astronomical lines have been reported by
(1) J. R. Pardo, C. Cabezas, J. P. Fonfría, M. Agúndez, F. Tercero, P. de Vincente, M. Guélin, and J. Cernicharo, 2021, Astron. Astrophys. 652, Art. No. L13.
The transition frequencies and their uncertainties were communicated by J. Cernicharo; the frequencies differ slightly from those in the letter. The uncertainties are close to those derived from standard errors, half those communicated.
For low N transitions, hyperfine splitting due to the ¹⁴N nucleus may be resolvable. Therefore, calcultions at lower frequencies should be viewed with some caution. The calcultions should be quite reliable up to 70 or 80 GHz.
The dipole moment was taken from an ab initio calculation in (1).