Anomalous Cepheids in the Sculptor dwarf galaxy

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/114162· OSTI ID:6988583

Smith, H A; Stryker, L L

The Sculptor dwarf galaxy contains at least three Cepheids (V25, V26, and V119), each with a period near 1 day and B magnitudes about 1.4 mag brighter than those of the Sculptor RR Lyrae stars. Low-resolution spectra of these so-called anomalous Cepheids were obtained. Metal abundances of the Cepheids have been determined by the Delta-S method and are found to be: Fe/H = -1.9 + or - 0.2, -1.8 + or - 0.2, and -2.2 + or - 0.3 for V25, V26, and V119, respectively. These values are consistent with the metal abundances of Sculptor red giants estimated from the color of the giant branch. Pulsational masses have been estimated for V25 and V26, but there is a need for improved photometry of these stars to obtain accurate results. It cannot be unambiguously established whether the Sculptor anomalous Cepheids are evolved single stars, aged about 3 Gyr, or whether they are created by mass transfer in older binary systems. The occurrence of anomalous Cepheids in other systems is discussed. There is some evidence that most anomalous Cepheids in the Small Magellanic Cloud are evolved single stars. 89 references.

• Research Organization: Michigan State Univ., East Lansing; Carnegie Institution of Washington, Washington, DC; Arizona State Univ., Tempe
• OSTI ID: 6988583
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 92; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102 -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
BINARY STARS
CEPHEIDS
DISTRIBUTION
GALAXIES
MAGELLANIC CLOUDS
MASS
MASS DISTRIBUTION
PULSATING VARIABLE STARS
SPATIAL DISTRIBUTION
SPECTROPHOTOMETRY
STAR EVOLUTION
STARS
VARIABLE STARS