A Spectroscopic Analysis of Blue Stragglers, Horizontal Branch and   Turn-Off Stars in Four Globular Clusters
  We present a spectroscopic analysis of HST/STIS and FOS low- and intermediate-resolution spectroscopy of 55 stars (turn-off stars, horizontal branch stars and blue stragglers) in four globular clusters (47 Tucanae, M3, NGC6752, and NGC6397). Stars were analyzed with non-Local Thermodynamic Equilibrium model atmospheres, and values for their effective temperatures and gravities and some rotation rates were obtained. Using photometric fluxes, we also obtained radii, luminosities and spectroscopic masses. 
Orsola De Marco, Michael M. Shara, D. Zurek, John A. Ouellette,   Thierry Lanz, Rex A. Saffer, Jeremy F. Sepinsky