Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-06-22
Astron. Astrophys., 375 (2001) 469
Astronomy and Astrophysics
Astrophysics
7 pages, 5 figures, 2 tables, accepted in Astronomy & Astrophysics
Scientific paper
10.1051/0004-6361:20010880
Frequency analysis of more than 300 stars of the OGLE database on Sculptor galaxy has led to the discovery of 18 double-mode RR Lyrae (RRd) variables. This yields a 20% incidence rate for double-mode pulsation among the variables previously classified as first overtone RR Lyrae stars in this galaxy. Most of the RRd stars cover the period range of 0.47d < P_0 < 0.49d but there are two stars with longer periods of ~0.54d. All variables fit well in the pattern of the P_0 --> P_1/P_0 diagram, spanned by the RRd stars of the Galactic globular clusters and those of the Large Magellanic Cloud (LMC). It follows from our previous investigations that the luminosities and masses of the RRd stars in Galactic globular clusters and in the LMC are almost independent of metallicity. By assuming that the Sculptor RRd variables also obey this rule, with the aid of the pulsation equations we estimate their metallicities. For most of the stars we get [Fe/H]~ -1.5, which is the same value as that obtained from a semi-empirical method for the average metallicity of the fundamental mode (RRab) stars. Two RRd stars have considerably lower metallicities, but even those are within the range corresponding to the RRab stars. The narrower metallicity range of the RRd stars is in agreement with their observed luminosity range, which is about three times smaller than that of the RRab stars.
No associations
LandOfFree
On the double-mode RR Lyrae variables of the Sculptor dwarf galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the double-mode RR Lyrae variables of the Sculptor dwarf galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the double-mode RR Lyrae variables of the Sculptor dwarf galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-435759