Calibrations of the reddening, luminosity, and abundance of old disk giants from photometry of stars in M67, NGC 3680, NGC 2420, and the Wolf 630 and Arcturus groups

Journal Article · Wed Jun 01 04:00:00 EDT 1983 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/113368· OSTI ID:5760499

Eggen, O J

Calibrations of photometric indices for red giants in the old disk population for the determination of reddening, luminosity, and metal abundance are discussed. The Wolf 630 Group and the cluster M67 are very similar with a photometrically determined abundance of P(Fe/H) = -0.25 and NGC 3680 has a value near -0.5. The latter may contain red stragglers (i.e., evolved blue stragglers). The Arcturus Group is very similar to the cluster NGC 2420 and has P(Fe/H)approx.-0.6. The main-sequence luminosity at R-I = 0.50, as a function of P(Fe/H), is shown to support the assumption that the halo main-sequence has small dispersion in luminosity.

• Research Organization: Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile
• OSTI ID: 5760499
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 88:6; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
AGE ESTIMATION
CALIBRATION
CHEMISTRY
COSMOCHEMISTRY
ELEMENTS
GIANT STARS
LUMINOSITY
MEASURING INSTRUMENTS
METALS
OPTICAL PROPERTIES
PHOTOMETERS
PHOTOMETRY
PHYSICAL PROPERTIES
RED GIANT STARS
STAR CLUSTERS
STARS