The ninth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) comprises RR Lyrae stars in the Small Magellanic Cloud (SMC). Our sample consists of 2475 variables, of which 1933, pulsate in the fundamental mode (RRab), 175 are the first overtone pulsators (RRc), 258 oscillate simultaneously in both modes (RRd) and 109 stars are suspected second-overtone pulsators (RRe). 30 objects are Galactic RR Lyr stars seen in the foreground of the SMC.
We discuss some statistical features of the sample. Period distributions show distinct differences between SMC and LMC populations of RR Lyr variables, with the SMC stars having on average longer periods. The mean periods for RRab, RRc and RRe stars are 0.596, 0.366 and 0.293 days, respectively. The mean apparent magnitudes of RRab stars are equal to 19.70 mag in the V-band and 19.12 mag in the I-band. Spatial distribution of RR Lyr stars shows that the halo of the SMC is roughly round in the sky, however the density map reveals two maxima near the center of the SMC.
For each object the multi-epoch V- and I-band photometry collected over 8 or 13 years of observations and finding charts are available to the astronomical community from the OGLE Internet archive.
PLEASE cite the following paper when using the data or referring to these OGLE results:
Soszyński et al., 2010, Acta Astron., 60, 165 (arXiv:1009.0528)
Any comments about the data and the form of their presentation are welcome as they can improve the future releases of catalogs of variable stars detected by the OGLE collaboration. Send your messages to this address.