Variable Stars in the Newly Discovered Milky Way Satellite in Bootes

2006 ◽  
Vol 653 (2) ◽  
pp. L109-L112 ◽  
Author(s):  
Massimo Dall'Ora ◽  
Gisella Clementini ◽  
Karen Kinemuchi ◽  
Vincenzo Ripepi ◽  
Marcella Marconi ◽  
...  
Keyword(s):  
Milky Way ◽  
Variable Stars

scholarly journals The Milky Way Revealed by Variable Stars. I. Sample Selection of RR Lyrae Stars and Evidence for Merger History

2022 ◽  
Vol 258 (1) ◽  
pp. 20
Author(s):  
Iminhaji Ablimit ◽  
Gang Zhao ◽  
Uy. Teklimakan ◽  
Jian-Rong Shi ◽  
Kunduz Abdusalam
Keyword(s):  
Milky Way ◽  
Sample Selection ◽  
Variable Stars ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Sky Survey ◽  
Spectroscopic Information ◽  
History Of ◽  
Dual Origin ◽  
Lyrae Stars

Abstract In order to study the Milky Way, RR Lyrae (RRL) variable stars identified by Gaia, ASAS-SN, and ZTF sky survey projects have been analyzed as tracers in this work. Photometric and spectroscopic information of 3417 RRLs including proper motions, radial velocity, and metallcity are obtained from observational data of Gaia, LAMOST, GALAH, APOGEE, and RAVE. Precise distances of RRLs with typical uncertainties less than 3% are derived by using a recent comprehensive period–luminosity–metallicity relation. Our results from kinematical and chemical analysis provide important clues for the assembly history of the Milky Way, especially for the Gaia–Sausage ancient merger. The kinematical and chemical trends found in this work are consistent with those of recent simulations that indicated that the Gaia–Sausage merger had a dual origin in the Galactic thick disk and halo. As recent similar works have found, the halo RRL sample in this work contains a subset of radially biased orbits besides a more isotropic component. This higher orbital anisotropy component amounts to β ≃ 0.8, and it contributes between 42% and 83% of the halo RRLs at 4 < R( kpc) < 20.

scholarly journals Variability Survey of ω Centauri in the Near-IR: Period-Luminosity Relations

2015 ◽  
Vol 12 (S316) ◽  
pp. 351-352
Author(s):  
C. Navarrete ◽  
M. Catelan ◽  
R. Contreras Ramos ◽  
F. Gran ◽  
J. Alonso-García ◽  
...  
Keyword(s):  
Time Series ◽  
Milky Way ◽  
Dwarf Galaxy ◽  
Variable Stars ◽  
Star Cluster ◽  
Wide Field ◽  
Time Series Study ◽  
Near Ir ◽  
Series Study

Abstractω Centauri is by far the most massive globular star cluster in the Milky Way, and possibly the remnant of a dwarf galaxy. As such, it contains a large number of variable stars of different classes. Here we report on an extensive, wide-field time-series study of ω Cen in the J and KS bands, which has allowed us to study the near-IR period-luminosity relations for different variability classes, including the first such relations for the SX Phoenicis stars.

scholarly journals Variable Stars in the MACHO Collaboration Database

1995 ◽  
Vol 155 ◽  
pp. 221-231 ◽  
Author(s):  
Kem H. Cook ◽  
C. Alcock ◽  
R.A. Allsman ◽  
T.S. Axelrod ◽  
K.C. Freeman ◽  
...  
Keyword(s):  
Dark Matter ◽  
Experimental Design ◽  
Preliminary Analysis ◽  
Milky Way ◽  
Variable Stars ◽  
Gravitational Microlensing ◽  
Be Star ◽  
Future Work ◽  
Baryonic Dark Matter ◽  
Massive Database

AbstractThe MACHO Collaboration’s search for baryonic dark matter via its gravitational microlensing signature has generated a massive database of time ordered photometry of millions of stars in the LMC and the bulge of the Milky Way. The search’s experimental design and capabilities are reviewed and the dark matter results are briefly noted. Preliminary analysis of the ~ 39,000 variable stars discovered in the LMC database is presented and examples of periodic variables are shown. A class of a periodically variable Be star is described which is the closest background to microlensing which has been found. Plans for future work on variable stars using the MACHO data are described.

scholarly journals Three classical Cepheid variable stars in the nuclear bulge of the Milky Way

Nature ◽  
2011 ◽  
Vol 477 (7363) ◽  
pp. 188-190 ◽  
Author(s):  
Noriyuki Matsunaga ◽  
Takahiro Kawadu ◽  
Shogo Nishiyama ◽  
Takahiro Nagayama ◽  
Naoto Kobayashi ◽  
...  
Keyword(s):  
Milky Way ◽  
Variable Stars ◽  
Classical Cepheid

scholarly journals A three-dimensional map of the Milky Way using classical Cepheid variable stars

Science ◽  
2019 ◽  
Vol 365 (6452) ◽  
pp. 478-482 ◽  
Author(s):  
Dorota M. Skowron ◽  
Jan Skowron ◽  
Przemek Mróz ◽  
Andrzej Udalski ◽  
Paweł Pietrukowicz ◽  
...  
Keyword(s):  
Star Formation ◽  
Simple Model ◽  
Spiral Galaxy ◽  
Stellar Population ◽  
Milky Way ◽  
Three Dimensional ◽  
Variable Stars ◽  
Three Dimensions ◽  
Classical Cepheid ◽  
Barred Spiral Galaxy

The Milky Way is a barred spiral galaxy, with physical properties inferred from various tracers informed by the extrapolation of structures seen in other galaxies. However, the distances of these tracers are measured indirectly and are model-dependent. We constructed a map of the Milky Way in three dimensions, based on the positions and distances of thousands of classical Cepheid variable stars. This map shows the structure of our Galaxy’s young stellar population and allows us to constrain the warped shape of the Milky Way’s disk. A simple model of star formation in the spiral arms reproduces the observed distribution of Cepheids.

scholarly journals A Dual CCD Mosaic Camera System Searching for Massive Compact Halo Objects (Machos)

1995 ◽  
Vol 167 ◽  
pp. 357-357
Author(s):  
Kem H. Cook
Keyword(s):  
Focal Plane ◽  
Preliminary Analysis ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Variable Stars ◽  
Magellanic Cloud ◽  
Camera System ◽  
Massive Compact Halo Objects ◽  
Photometric Measurements ◽  
Analysis System

The Macho Collaboration uses a dedicated 1.27-m telescope (The Great Melbourne Telescope) at Mount Stromlo to make photometric measurements of tens of millions of stars per night searching for the gravitational microlensing signature of MACHOs in the halo and disk of the Milky Way. A prime focus corrector and dichroic beamsplitter provide red (6300–7800 å) and blue (4500–6300 å) foci with one degree fields. A two by two mosaic of 2048 × 2048 pixel CCDs in each focal plane provides simultaneous images of 0.5 square degrees. By August of 1994, more than 20,000, 32 Megapixel images will have been collected of fields in the Large Magellanic Cloud (LMC), Small Magellanic Cloud and the bulge of the Milky Way. We have implemented an online analysis system which produces photometric reductions of a night's data (five Gbyte of images) within 24 hours. This system allows us to identify and follow interesting events in real-time. In this search, we have identified more than 60,000 variable stars, and a preliminary analysis of their types and distribution will be presented. Microlensing events toward the LMC and the bulge have been discovered and detection efficiencies are being calculated to constrain the MACHO content of the Milky Way's halo.

scholarly journals Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I

2008 ◽  
Vol 674 (2) ◽  
pp. L81-L84 ◽  
Author(s):  
Charles Kuehn ◽  
Karen Kinemuchi ◽  
Vincenzo Ripepi ◽  
Gisella Clementini ◽  
Massimo Dall'Ora ◽  
...  
Keyword(s):  
Milky Way ◽  
Variable Stars
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