Elemental abundances of the mercury--manganese stars HR 89 and 33 Geminorum

Abstract

Using atlas9 model atmospheres and two spectrograms each of the mercury-manganese stars HR 89 and 33 Geminorum obtained with a 3 kpixel long CCD, camera 5 and grating A at the Kitt Peak National Observatory coudé feed telescope, we derive the elemental abundances of these stars. Both are extraordinary objects with Mn abundances similar to those of Fe and marked He deficiencies. 33 Gem is the hottest known HgMn star.