CfA OIR Division Lunch Talks

Thursday, April 3, 2008, 12:30 pm, Pratt Conference Room

The Children of Andromeda

Dr. Nelson Caldwell (CfA)

In the last decade, stars and star clusters in the Andromeda galaxy have been examined in ways previously possible only in the Milky Way. I will present the results of one such project, which centers around a large spectroscopic survey of star clusters and planetary nebulae done at the MMT Observatory with SAO's Hectospec multifiber spectrograph. High quality spectra of over 500 clusters have been obtained, with over 300 of those being globular clusters (there are 150 known globulars in the Milky Way). Ages and abundances may be estimated from these spectra, and the kinematics of the different kinds of clusters may be analyzed and compared with the kinematics of the planetaries and the unresolved light of the disk (also observed with Hectospec). Several clusters, planetaries and one star can be identified as part of the giant stream, the remnant of a dwarf galaxy.

Hectospec spectra around M31