Related papers: RR Lyrae Stars in the MACHO Database
We analyze the mean luminosity of three samples of field RRab Lyr stars observed in the course of the OGLE microlensing experiment: 73 stars from the Galactic bulge and 110 and 128 stars from selected fields in the LMC and SMC,…
The properties of RR Lyrae variables make them excellent probes of the formation and evolution of a stellar population. The mere presence of such stars necessitates an age greater than ~10 Gyr while their periods and amplitudes can be used…
We characterize the spatial density of the Pan-STARRS1 (PS1) sample of RR Lyrae stars, to study the properties of the old Galactic stellar halo as traced by RRab stars. This sample of 44,403 sources spans Galactocentric radii of $0.55 \;…
42 RRab, 46 RRc and 7 previously unidentified double-mode RR Lyrae stars were found in the publicly available data of the WASP archive. The Galactic double-mode RR Lyrae stars appear to show a bimodal period distribution.
We present time-series $BVI$ photometry for the Galactic globular cluster NGC 6402 (M14). The data consists of $\sim$137 images per filter, obtained using the 0.9m and 1.0m SMARTS telescopes at the Cerro Tololo Inter-American Observatory.…
We present for the first time a detailed spectroscopic study of chemical element abundances of metal-poor RR Lyrae stars in the Large and Small Magellanic Cloud (LMC and SMC). Using the MagE echelle spectrograph at the 6.5m Magellan…
RR Lyrae stars are of great importance for investigations of Galactic structure. However, a complete compendium of all RR-Lyraes in the solar neighbourhood with accurate classifications and coordinates does not exist to this day. Here we…
The VISTA Variables in the V\'ia L\'actea (VVV) is a near-IR time-domain survey of the Galactic bulge and southern plane. One of the main goals of this survey is to reveal the 3D structure of the Milky Way through their variable stars.…
The 3D structure of the inner Small Magellanic Cloud (SMC) is investigated using the red clump (RC) stars and the RR Lyrae stars (RRLS). The V and I pass bands photometric data from the Optical Gravitational Lensing Experiment (OGLE III)…
MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that objects (dubbed MACHOs) with masses in the range $10^{-6}M_\odot < M \simlt 100…
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…
Context. Globular clusters (GCs) are witnesses of the past accretion events onto the Milky Way (MW). In particular, the GCs of the Sagittarius (Sgr) dwarf galaxy are important probes of an on-going merger. Aims. Our main goal is to search…
A search for RR Lyrae stars (RRLS) in 840 sq.deg. of the sky in right ascension 150 - 210 deg and declination -10 - +10 deg yielded 1013 type ab and 359 type c RRLS. This sample is used to study the density profile of the Galactic halo,…
We present 838 ab-type RR Lyrae stars from the Lowell Observatory Near Earth Objects Survey Phase I (LONEOS-I). These objects cover 1430 deg^2 and span distances ranging from 3-30 kpc from the Galactic Center. Object selection is based on…
Stellar ages are critical for understanding the temporal evolution of a galaxy. We calculate the ages of over 6000 red giant branch stars in the Large Magellanic Cloud (LMC) observed with SDSS-IV / APOGEE-S. Ages are derived using…
The properties of RR Lyrae variables make them excellent probes of the formation and evolution of a stellar population. The mere presence of such stars necessitates an age greater than ~10 Gyr while their periods and amplitudes can be used…
In the early nineties several teams started large scale systematic surveys of the Magellanic Clouds and the Galactic Bulge to search for microlensing effects. As a by product, these groups have created enormous time-series databases of…
We present a comprehensive analysis of the variable stars projected on the field of the Galactic bulge globular cluster NGC 6522, offering valuable insights into their characteristics. Using proper motions from Gaia DR3, we aim to…
Radial velocities of fifteen double-mode bulge RR Lyrae (RR01) stars are presented, six of which belong to a compact group of RR01 stars in pulsation space, with the ratio of first-overtone period to fundamental-mode period,…
We investigate the red supergiant (RSG) content of the SMC and LMC using multi-object spectroscopy on a sample of red stars previously identified by {\it BVR} CCD photometry. We obtained high accuracy ($<1$ km s$^{-1}$) radial velocities…