Top and middle panels: five lines of AlO observed in the submm-wave, single sideband spectra of Mira obtained in 2013−2015 with APEX. The features of AlO are broader (FWHM) than most other lines owing to unresolved hyperfine splitting (the components are shown as red bars). Bottom: an archival spectrum of Mira obtained with Herschel in July 2010, where one other transition of AlO was observed. This double side-band spectrum contains a large number of emission lines from different species in two overlapping frequency ranges. This spectrum is smoothed to a lower resolution than in the APEX spectra shown in the upper panels.