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Related papers: Variable Stars and Galactic Structure

200 papers

The lifetime of solar-like stars, the envelope structure of more massive stars, and stellar acoustic frequencies largely depend on the radiative properties of the stellar plasma. Up to now, these complex quantities have been estimated only…

We report VI CCD photometry of the globular cluster cluster NGC 1851. We aim to study the membership of the variable stars detected in the field of the cluster as listed in the Catalogue of Variable stars in Globular Clusters (CVSGC;…

Solar and Stellar Astrophysics · Physics 2024-08-22 A. Arellano Ferro , C. E. Pérez Parra , M. A. Yepez , I. H. Bustos Fierro , Z. Prudil , L. J. Zerpa Guillen

We describe variable stars found in the data collected during the OGLE-III Shallow Survey covering the I-band magnitude range from 9.7 mag to 14.5 mag. The main result is the extension of period--luminosity relations for Cepheids up to 134…

Radial abundance gradients are observed in the Galaxy and other galaxies as well, and include several chemical elements in different stellar systems. Possibly the most accurate gradients in the Galaxy are those determined from chepheid…

Astrophysics of Galaxies · Physics 2019-06-06 W. J. Maciel , S. Andrievsky

Both star clusters and variable stars are sensitive laboratories of stellar astrophysics and evolution: cluster member stars provide context for interpreting cluster populations, whereas variability reveals the nature of individual stellar…

Solar and Stellar Astrophysics · Physics 2025-08-19 Richard I. Anderson , Emily L. Hunt

Mass loss and variability are two linked, fundamental properties of evolved stars. In this paper I review our current understanding of these processes, with a particular focus on how observations and models are used to constrain reliable…

Solar and Stellar Astrophysics · Physics 2014-12-15 Massimo Marengo

Most of our knowledge about the structure of the Milky Way has come from the study of variable stars. Among the variables, mimicking the periodic variation of pulsating stars, are the eclipsing binaries. These stars are important in…

Solar and Stellar Astrophysics · Physics 2021-03-31 E. Botan , R. K. Saito , D. Minniti , A. Kanaan , R. Contreras Ramos , T. S. Ferreira , L. V. Gramajo , M. G. Navarro

We present a search and analysis of variable stars in the recently discovered Crater~II dwarf galaxy. Based on $B$, $V$, $I$ data collected with the Isaac Newton Telescope (FoV$\sim$0.44 square degrees) we detected 37 variable stars, of…

The POINT-AGAPE collaboration has been monitoring M31 for three seasons with the Wide Field Camera on the Isaac Newton Telescope. In each season, data are taken for one hour per night for roughly sixty nights during the six months that M31…

Cepheids provide approaches to determining binary parameters which are often complementary to those for main sequence massive and intermediate mass stars. Specifically, we are using high resolution imaging, radial velocities, and X-ray…

Solar and Stellar Astrophysics · Physics 2014-01-22 Nancy Remage Evans

The full spatio-chemo-dynamical structure of galaxies of all types and environments at low redshift provides a critical accompaniment to observations of galaxy formation at high redshift. The next decade brings the observational opportunity…

Investigating period changes of classical Cepheids through the framework of $O-C$ diagrams provides a unique insight to the evolution and nature of these variable stars. In this work, the new or extended $O-C$ diagrams for 148 Galactic…

Solar and Stellar Astrophysics · Physics 2022-02-02 G. Csörnyei , L. Szabados , L. Molnár , B. Cseh , N. Egei , Cs. Kalup , V. Kecskeméthy , R. Könyves-Tóth , K. Sárneczky , R. Szakáts

The stellar evolution theory of massive stars remains uncalibrated with high-precision photometric observational data mainly due to a small number of luminous stars that are monitored from space. Automated all-sky surveys have revealed…

Solar and Stellar Astrophysics · Physics 2017-02-08 Jaan Laur , Indrek Kolka , Tõnis Eenmäe , Taavi Tuvikene , Laurits Leedjärv

We have calculated the physical parameters of the RR Lyrae stars in the globular cluster NGC~4147 via the Fourier decomposition of their light curves, using new data and well-established semi-empirical calibrations and zero points. The mean…

Solar and Stellar Astrophysics · Physics 2018-03-15 A. Arellano Ferro , F. C. Rojas Galindo , S. Muneer , Sunetra Giridhar

Future space and ground-based survey programmes will produce an impressive amount of photometric data. The GAIA space mission will map the complete sky down to mag V=20 and produce time series for about 1 billion stars. Survey instruments…

Astrophysics · Physics 2007-05-23 Laurent Eyer , Jan Cuypers

The studies of pulsating variable stars are traditional subjects of astronomers in Odessa. In the last half of the 20th century, the studies of the physical variable stars were the topics of 15 PhD theses of the collaborators of the Odessa…

Solar and Stellar Astrophysics · Physics 2014-11-06 Larisa S. Kudashkina , Ivan L. Andronov , Vladislava I. Marsakova , Lidia L. Chinarova

We have performed a search for variable stars in the dwarf irregular galaxy NGC 6822 using wide-field multi-epoch VI photometry down to a limiting magnitude $V$ $\sim$ 22. Apart from the Cepheid variables in this galaxy already reported in…

Astrophysics · Physics 2009-11-11 R. E. Mennickent , W. Gieren , I. Soszynski , G. Pietrzynski

The period of pulsation and the structure of the light curve for Cepheid and RR Lyrae variables depend on the fundamental parameters of the star: mass, radius, luminosity, and effective temperature. Here we train artificial neural networks…

Solar and Stellar Astrophysics · Physics 2020-01-08 Earl P. Bellinger , Shashi M. Kanbur , Anupam Bhardwaj , Marcella Marconi

Here we review the efforts of a number of recent results that use old tracers to understand the build up of the Galaxy. Details that lead directly to using these old tracers to measure distances are discussed. We concentrate on the…

The secondary, Roche-lobe filling stars in cataclysmic variables (CVs) are key to our understanding of the origin, evolution and behaviour of this class of interacting binary. We review the basic properties of the secondary stars in CVs and…

Astrophysics · Physics 2007-05-23 V. S. Dhillon , C. A. Watson