CN and CA abundance variations among the giants in M22

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

41

Abundance, Calcium, Cyanogen, Globular Clusters, Horizontal Branch Stars, Red Giant Stars, Stellar Composition, Color-Magnitude Diagram, Cyanates, Metallicity, Stellar Spectrophotometry

Scientific paper

We have obtained uvbyCa data for over 300 giants and horizontal-branch stars in three fields of M22. The spread in (b - y) for the giant and horizontal branches is consistent with a spread in foreground reddening delta E (B - V) is approximately equal to 0.08. Reanalysis of the data of Norris and Freeman (1983) indicates not only positive correlations between CH, CN, and Ca, but decidely bimodal distributions of CH and CN and a unimodal distribution for Ca. Our photometric indices, m1 and hk, demonstrate a range in metallicity that persists to two magnitudes below the horizontal branch, and confirms the correlation between calcium abundance and CN/CH. We infer from comparisons to spectroscopic data that m1 is dominated by the CN and CH abundance and find no independent evidence of a range in (Fe/H). The excessive ranges in m1 and hk also suggest the influence of a continuous opacity source, reminiscent of the Bond-Neff effect, that is correlated with CNO abundance. The relative contributions of internal mixing and primordial variations for M22's giants are discussed.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

CN and CA abundance variations among the giants in M22 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with CN and CA abundance variations among the giants in M22, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CN and CA abundance variations among the giants in M22 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-836885

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.