Rotation and Activity in the Solar‐Metallicity Open Cluster NGC 2516

We report new measures of radial velocities and rotation rates ( v sin i ) for 51 F and early G stars in the open cluster NGC 2516 and combine these with previously published data. From high signal-to-noise ratio spectra of two stars, we show that NGC 2516 has a relative iron abundance with respect to the Pleiades of Δ[Fe/H] = +0.04 ± 0.07 at the canonical reddening of E ( B - V ) = 0.12, in contrast to previous photometric studies that placed the cluster 0.2-0.4 dex below solar. We construct a color-magnitude diagram based on radial velocity members and explore the sensitivity of photometric determinations of the metallicity and distance to assumed values of the reddening. For a metal abundance near solar, the Hipparcos distance to NGC 2516 is probably underestimated. Finally, we show that the distribution of rotation rates and X-ray emission does not differ greatly from that of the Pleiades, when allowance is made for the somewhat older age of NGC 2516.