A broad perspective on multiple abundance populations in the globular
  cluster NGC 1851
  We present an analysis of the multiple stellar populations of the globular
cluster NGC 1851. We used lower resolution spectra of giant stars to measure
CN, CH, and calcium H & K spectral indices, and determine elemental abundances
for carbon and nitrogen. The CN and CH indices were used to confirm that there
are four populations of stars in the cluster. The primordial population of
stars, with the lowest CN, was found to be generally chemically distinct in
elemental abundances from the second generation populations. As expected,
[N/Fe] increases with increasing CN strength, but the only other element that
correlated with CN was barium. The two largest populations of stars were found
to have the same rate of carbon astration as the stars ascend the giant branch.
We were also able to confirm that four previously identified extratidal stars
are chemically associated with the cluster. This work shows the benefit of
considering the chemistry of globular clusters with both high- and
low-resolution spectra.
