A WFC3/HST VIEW OF THE THREE STELLAR POPULATIONS IN THE GLOBULAR CLUSTER NGC 6752

Journal Article · Sat Apr 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/2/120· OSTI ID:22126910

Milone, A. P.; Marino, A. F.; others, and

Multi-band Hubble Space Telescope photometry reveals that the main sequence, sub-giant, and the red-giant branch of the globular cluster NGC 6752 splits into three main components in close analogy with the three distinct segments along its horizontal branch stars. These triple sequences are consistent with three stellar groups: a stellar population with a chemical composition similar to field-halo stars (Population a), a Population (c) with enhanced sodium and nitrogen, depleted carbon and oxygen, and an enhanced helium abundance ({Delta}Y {approx} 0.03), and a Population (b) with an intermediate (between Populations a and c) chemical composition and slightly enhanced helium ({Delta}Y {approx} 0.01). These components contain {approx}25% (Population a), {approx}45% (Population b), and {approx}30% (Population c) of the stars. No radial gradient for the relative numbers of the three populations has been identified out to about 2.5 half-mass radii.

• OSTI ID: 22126910
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CARBON
CHEMICAL COMPOSITION
HELIUM
MASS
NITROGEN
OXYGEN
PHOTOMETRY
POPULATIONS
SODIUM
SPACE
STARS