\def\kms{km s$^{-1}$}
Rotational Velocities for Blue Horizontal Branch Stars in Globular Clusters
Session 50 -- Globular Clusters
Display presentation, Wednesday, 9:20-6:30, Pauley Room

## [50.03] Rotational Velocities for Blue Horizontal Branch Stars in Globular Clusters

Ruth C. Peterson (UCO/Lick), Deborah A. Crocker (UAlabama), Robert T. Rood (UVa)

Rotational velocities $v \sin i$ are derived for two dozen stars in each of the globular clusters M3, M13, and NGC 288. Rotation is most prevalent in M13: most stars are rotating more rapidly than 20 \kms, and a half dozen more rapidly than 30 \kms. In M3, only a few are rotating more rapidly than 20 \kms, and none reach this level in NGC 288. We illustrate our method of determining $v \sin i$ from fits to a grid of synthetic spectra, present the results for the stars observed in each cluster, and discuss the distribution of $v \sin i$ values and their ramifications for stellar evolution and the appearance of the globular-cluster color-magnitude diagram.