OGLE RR Lyrae stars in Galactic bulge and disk

The size of our sample has been doubled and reached 78350 RR Lyr variables, of which 56508 are fundamental-mode pulsators (RRab stars), 21321 pulsate solely in the first-overtone (RRc stars), 458 are classical double-mode pulsators (RRd stars), and 63 are anomalous RRd variables (including five triple-mode pulsators). For all the newly identified RR Lyr stars, we publish time-series photometry obtained during the OGLE Galaxy Variability Survey.

We present the spatial distribution of RR Lyr stars on the sky, provide a list of globular clusters hosting RR Lyr variables, and discuss the Petersen diagram for multimode pulsators. We find new RRd stars belonging to a compact group in the Petersen diagram (with period ratios P_1O_/P_F_~0.74 and fundamental-mode periods P_F_~0.44d) and we show that their spatial distribution is roughly spherically symmetrical around the Milky Way center.