Office: Kerr 231A
Robert Kraft's current research interest is the chemical composition, kinematics, and spatial distribution of stars in the halo of our galaxy and other galaxies. He and his research associates (Smith, UCSC; Sneden, University of Texas; Langer, Colorado College) and graduate student (Shetrone) have been studying the composition gradient, motions, and locations of RR Lyrae stars and evolved blue stars in the far halo, in order to test whether the galaxy was formed in a single collapse or was assembled from already-formed small stellar subsystems.
A second problem has to do with the chemical composition of evolved stars in globular clusters. One can examine the changes in the surface abundances that result from the dredgeup to the surface of material that has experienced nuclear reactions as a globular cluster star evolves. The spectroscopy of globular cluster stars gives puzzling results, which suggest that mixing and dredgeup in late evolutionary stages is not well understood.