2008/08/19 by K. Kinemuchi, Karen Kinemuchi, Hugh C. Harris +8 · 82 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Cepheid variable #Dwarf galaxy #Dwarf spheroidal galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Globular cluster #Interacting galaxy #Metallicity #Photometry (optics) #Physics #RR Lyrae variable #Stars #Stellar, planetary, and galactic studies #Variable star #astro-ph
paper · pdf · doi:10.1088/0004-6256/136/5/1921
published in The Astronomical Journal 136(5), 1921-1939 (Institute of Physics) · Accepted to AJ. 61 pages, 14 figures, 10 tables
arxiv created 2008/08/19 · openalex publication_date 2008/10/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We present a CCD survey of variable stars in the Draco dwarf spheroidal galaxy. This survey, which has the largest areal coverage since the original variable star survey by Baade & Swope, includes photometry for 270 RR Lyrae (RRL) stars, 9 anomalous Cepheids (ACs), 2 eclipsing binaries, and 12 slow, irregular red variables, as well as 30 background QSOs. Twenty-six probable double-mode RRL stars were identified. Observed parameters, including mean V and I magnitudes, V amplitudes, and periods, have been derived. Photometric metallicities of the ab-type RRL stars were calculated according to the method of Jurcsik & Kovacs, yielding a mean metallicity of 〈[Fe/H]〉 = −2.19 ± 0.03. The well-known Oosterhoff intermediate nature of the RRL stars in Draco is reconfirmed, although the double-mode RRL stars, with one exception, have properties similar to those found in Oosterhoff type II globular clusters. The period–luminosity relation of the ACs is rediscussed with the addition of the new Draco ACs.