New variable stars discovered in the fields of three Galactic open clusters using the VVV Survey
| Autor: | L. V. Gramajo, C. Bonatto, Juan J. Clariá, S. Ramírez Alegría, I. Dékány, T. Palma, Javier Alonso-García, Dante Minniti |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
INDIVIDUAL
Vista Variables in the Via Lactea ASCC 90 Cepheid variable Ciencias Físicas Phase dispersion minimization FOS: Physical sciences GENERAL Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics RR Lyrae variable 01 natural sciences VARIABLES ANTALOVAundefined1 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Instrumentation Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics 010308 nuclear & particles physics STELLAR CONTENT undefined OPEN CLUSTERS AND ASSOCIATIONS Astronomy Astronomy and Astrophysics Light curve Astrophysics - Astrophysics of Galaxies Galaxy GALAXY Astronomía Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) ESOundefined393-15 undefined STARS Astrophysics::Earth and Planetary Astrophysics Variable star CIENCIAS NATURALES Y EXACTAS Open cluster |
| Popis: | This project is a massive near-infrared (NIR) search for variable stars in highly reddened and obscured open cluster (OC) fields projected on regions of the Galactic bulge and disk. The search is performed using photometric NIR data in the $J$-, $H$- and $K_s$- bands obtained from the Vista Variables in the V\'ia L\'actea (VVV) Survey. We performed in each cluster field a variability search using Stetson's variability statistics to select the variable candidates. Later, those candidates were subjected to a frequency analysis using the Generalized Lomb-Scargle and the Phase Dispersion Minimization algorithms. The number of independent observations range between 63 and 73. The newly discovered variables in this study, 157 in total in three different known OCs, are classified based on their light curve shapes, periods, amplitudes and their location in the corresponding color-magnitude $(J-K_s,K_s)$ and color-color $(H-K_s,J-H)$ diagrams. We found 5 possible Cepheid stars which, based on the period-luminosity relation, are very likely type II Cepheids located behind the bulge. Among the newly discovered variables, there are eclipsing binaries, $\delta$ Scuti, as well as background RR Lyrae stars. Using the new version of the Wilson & Devinney code as well as the "Physics Of Eclipsing Binaries" (PHOEBE) code, we analyzed some of the best eclipsing binaries we discovered. Our results show that these studied systems turn out to be ranging from detached to double-contact binaries, with low eccentricities and high inclinations of approximately $80^{\circ}$. Their surface temperatures range between $3500$K and $8000$K. Comment: 34 pages, 10 figures, 7 tables. Accepted for publication in New Astronomy |
| Databáze: | OpenAIRE |
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