CN and CH inhomogeneities among red horizontal branch stars in M71

Journal Article · Mon May 01 00:00:00 EDT 1989 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/115080· OSTI ID:5629554

Smith, G H; Penny, A J

Spectra have been obtained of a sample of horizontal branch stars in the globular cluster M71. These display clear variations in the strengths of the 3883-A and 4215-A CN bands, with the former of these features showing a bimodal distribution. A clear anticorrelation exists between the strength of the 3883-A CN band and the CH absorption in the region of the 4300-A G band, indicating that part of the surface material of the CN-strong stars has been processed through the CN cycle of hydrogen burning. The percentage of CN-strong stars found on the horizontal branch is consistent with that observed by Smith and Norris (1982) on the giant branch of M71. Hence, there is no evidence from the available data that the percentage of these stars increases during the transition between the red giant and horizontal branch stages of evolution. 39 refs.

• Research Organization: Space Telescope Science Institute, Baltimore, MD (USA); SERC, Rutherford Appleton Laboratory, Didcot (England)
• OSTI ID: 5629554
• Journal Information: Astron. J.; (United States), Vol. 97
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
STAR CLUSTERS
CHEMICAL COMPOSITION
ABUNDANCE
AGE ESTIMATION
CYANOGEN
HYDROCARBONS
HYDROGEN BURNING
RED GIANT STARS
SPECTRA
STAR EVOLUTION
VARIATIONS
GIANT STARS
ORGANIC COMPOUNDS
STAR BURNING
STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources