Rotation and Hα Emission in a Young SMC Cluster: a Spectroscopic View of NGC 330

We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff of the young (similar to 40 Myr) Small Magellanic Cloud globular cluster NGC 330. Spectra were obtained with the Michigan/Magellan Fiber System and Magellan Inamori Kyocera Echelle spectrographs located on the Magellan-Clay 6.5 m telescope. These spectra revealed the presence of Be stars, occupying primarily the cool side of the split main sequence. Rotational velocity (v sin i) measurements for most of the targets are consistent with the presence of two populations of stars in the cluster: one made up of rapidly rotating Be stars (< v sin i > approximate to 200 km s(-1)) and the other consisting of warmer stars with slower rotation (< v sin i > approximate to 50 km s(-1)). Core emission in the H delta photospheric lines was observed for most of the H alpha emitters. The shell parameter computed for the targets in our sample indicates that most of the observed stars should have inclinations below 75 degrees. These results confirm the detection of Be stars obtained through photometry but also reveal the presence of narrow H alpha and H delta features for some targets that cannot be detected with low-resolution spectroscopy or photometry. Asymmetry variability of H alpha line profiles on the timescales of a few years is also observed and could provide information on the geometry of the decretion disks. Observations revealed the presence of nebular H alpha emission, strong enough in faint targets to compromise the extraction of spectra and to impact narrow-band photometry used to assess the presence of H alpha emission.