Related papers: RR Lyrae variables in the dwarf spheroidal galaxy …

Almost every known low-luminosity Milky Way dwarf spheroidal (dSph) satellite galaxy contains at least one RR Lyrae star. Assuming that a fraction of distant (60 < d_{helio} < 100 kpc) Galactic halo RR Lyrae stars are members of yet to be…

We present a search for variable stars in the Fornax dwarf galaxy covering an area of 1/2 a square degree. We have ~30 epochs of VI data. We found and determined periods for more than 500 RR Lyrae, 17 anomalous Cepheids, 6 Population II…

We present an upgrade of the OGLE Collection of RR Lyrae stars in the Galactic bulge and disk. The size of our sample has been doubled and reached 78 350 RR Lyr variables, of which 56 508 are fundamental-mode pulsators (RRab stars), 21 321…

We use the fundamental-mode RR Lyr-type variable stars (RRab) from OGLE-IV survey to draw a 3D picture of the central part of the tidally disrupted Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. We estimate the line-of-sight thickness of…

We present the first stellar spectroscopy in the low-luminosity (M_V ~-9.3 mag), dwarf galaxy Leo P. Its significantly low oxygen abundance (3% solar) and relative proximity (~1.6 Mpc) make it a unique galaxy to investigate the properties…

We present the first results of a variable star search in the field and in the globular clusters of the Fornax dwarf spheroidal galaxy. Variable stars were identified using the Image Subtraction Technique (Alard 2000) on time-series data…

CCD observations for 10 (6 previously known and 4 newly discovered) of the 11 RR Lyrae variables in NGC 5897 have been analysed. The period-luminosity and period-amplitude plots indicate that the population of RR Lyrae variables in NGC 5897…

We report the discovery of a new double-mode RR Lyrae variable (RRd) in the field of our Galaxy: CU Comae. CU Comae is the sixth such RRd identified to date and is the most metal-poor RRd ever detected. Based on BVI CCD photometry spanning…

We report 272 radial velocities for 19 RR Lyrae variables. For most of the stars we have radial velocities for the complete pulsation cycle. These data are used to determine robust center--of--mass radial velocities that have been compared…

We present B and V time series photometry of the M31 satellite galaxy Andromeda XXVII (And XXVII) that we observed with the Large Binocular Cameras of the Large Binocular Telescope. In the field of And XXVII we have discovered a total of 90…

We present the analysis of 12227 type-ab RR Lyrae found among the 200 million public lightcurves in the Catalina Surveys Data Release 1 (CSDR1). These stars span the largest volume of the Milky Way ever surveyed with RR Lyrae, covering…

We present predicted relations connecting pulsational and evolutionary parameters, as based on a wide set of convective pulsating models of RR Lyrae stars with Z=0.001, Y=0.24 and mass and luminosity suitable for the ``old'' (age $>$ 8 Gyr)…

We present new period-$\phi_{31}$-[Fe/H] relations for first overtone RRL stars (RRc), calibrated over a broad range of metallicities ($-2.5 < \textrm{[Fe/H]}< 0.0$) utilizing the largest currently available set of Galactic halo field RRL…

We collected over 6000 high-resolution spectra of four dozen field RR Lyrae (RRL) variables pulsating either in the fundamental (39 RRab) or in the first overtone (9 RRc) mode. We measured radial velocities (RVs) of four strong metallic and…

We present preliminary results concerning the search for short-period variable stars in Tucana and LGS3 based on very deep HST/ACS imaging. In the fraction of the observed field we studied in each galaxy, a total of 133 and 30 variables…

We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediate resolution spectra and infrared images were obtained with FORS1 at the ESO VLT and with the…

We present radial velocities of 33 red giants in the Leo I dSph galaxy obtained from spectra taken with the HIRES echelle spectrograph on the Keck I telescope. These data have a mean precision of 2.2 km/s and lead to estimates of the…

We use deep Hubble Space Telescope imaging to study the resolved stellar populations in BST1047+1156, a gas-rich, ultradiffuse dwarf galaxy found in the intragroup environment of the Leo I galaxy group. While our imaging reaches…

An examination of the period-V amplitude relation for RRab stars (fundamental mode pulsators) with `normal' light curves in the Oosterhoff type I clusters M3 and M107 and in the Oosterhoff type II clusters M9 and M68 reveals that the V…

We combine precision radial velocity data from four different published works of the stars in the Leo II dwarf spheroidal galaxy. This yields a dataset that spans 19 years, has 14 different epochs of observation, and contains 372 unique red…