  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 X^2 Sigma^+ state of AlO have been
reinvestigated. Comparisons between Fourier transform and microwave data
indicate a discrepancy regarding the derived value of gamma_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 X^2 Sigma^+. 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.
