A comparison of stellar populations in the Andromeda galaxy and its elliptical companion

. For selected fields in the Andromeda Galaxy, M 31, and in its elliptical companion, NGC 205, the resolved stars were counted and the surface brightnesses measured photoelectrically. The count-brightness ratio thus obtained was found to be significantly higher for the companion than for the Andromeda Galaxy. The count-brightness ratio for the companion agrees with that for globular clusters, whereas the ratio for the Andromeda Galaxy agrees with that for the solar neighborhood. This indicates that the bulk of the light of the Andmmeda Galaxy is contributed not by extreme Population II stars but likely by old Population I stars.