Mg I emission lines at 12 and 18 mu m in K giants
Context. The solar mid-infrared metallic emission lines have already been observed and analyzed well, and the formation scenario of the Mg I 12 mu m lines has been known for more than a decade. Detections of stellar emission at 12 mu m have, however, been limited to Mg I in very few objects. Previous modeling attempts have been made only for Procyon and two cool evolved stars, with unsatisfactory