We present alpha element to iron abundance ratios , \text { [ } \alpha / \text { Fe ] } , for four stars in the outer stellar halo of the Andromeda Galaxy ( M 31 ) .
The stars were identified as high-likelihood field halo stars by Gilbert et al .
( 13 ) and lie at projected distances between 70 and 140 kpc from M31 ’ s center .
These are the first alpha abundances measured for a halo star in a galaxy beyond the Milky Way .
The stars range in metallicity between [ Fe/H ] = -2.2 and [ Fe/H ] = -1.4 .
The sample ’ s average \text { [ } \alpha / \text { Fe ] } ratio is +0.20 \pm 0.20 .
The best-fit average value is elevated above solar which is consistent with rapid chemical enrichment from Type II supernovae .
The mean \text { [ } \alpha / \text { Fe ] } ratio of our M31 outer halo sample agrees ( within the uncertainties ) with that of Milky Way inner/outer halo stars that have a comparable range of [ Fe/H ] .