2009A&A...508.1067L

The detection of rotational transitions of the AlO radical at millimeter wavelengths from an astronomical source has recently been reported. In view of this, rotational transitions in the ground X²Σ⁺ state of AlO have been reinvestigated. Comparisons between Fourier transform and microwave data indicate a discrepancy regarding the derived value of γ_D in the v=0 level of the ground state. This discrepancy is discussed in the light of comparisons between experimental data and synthesized rotational spectra in the v=0, 1 and 2 levels of X²Σ⁺. A list of calculated rotational lines in v=0, 1 and 2 of the ground state up to N'=11 is presented which should aid astronomers in analysis and interpretation of observed AlO data and also facilitate future searches for this radical.