Broad-band j, H, and K magnitudes and narrow-band CO and H2O indices for 25 giant and horizontal-branch stars in the strong-lined globular cluster M7 1 are presented. These data are compared with similar data for M67 and for metal-poor globular clusters. In most photometric indices the M71 stars are intermediate between M67 and the metal-poor globulars, although the M71 giant branch extends to considerably cooler temperatures. Bolometric magnitudes and effective temperatures determined for the M7 1 stars also place this cluster between the other globulars and M67. A theoretical analysis of the CO indices indicates that M71 is metal deficient by 0.4 (+- 0.2) dex in the mean with respect to field giants. The relationship between the CO indices and CN absorption strengths as determined from DDO photometry is as expected from empirically determined temperature dependences and theoretically determined abundance dependences. Subject headings: clusters: globular - stars: abundances - stars: Population II
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Frogel et al. (1979) studied this question.