A Sr-rich Star on the Main Sequence of ω Centauri

Abundance ratios relative to iron for carbon, nitrogen, strontium, and barium are presented for a metal-rich main-sequence star ([Fe/H] = -0.74) in the globular cluster ω Centauri. This star, designated 2015448, shows depleted carbon and solar nitrogen but, more interestingly, shows an enhanced abundance ratio of strontium [Sr/Fe] ≈ 1.6 dex, while the barium abundance ratio is [Ba/Fe] ≤ 0.6 dex. At this metallicity one usually sees strontium and barium abundance ratios that are roughly equal. Possible formation scenarios of this peculiar object are considered.