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Title: | Gaia Data Release 2, Variable stars in the colour-absolute magnitude diagram |
Author: | Gaia Collaboration Voss, Hölger Luri Carrascoso, Xavier Antoja Castelltort, M. Teresa Romero Gómez, Mercè Figueras Siñol, Francesca Fabricius, Claus Masana Fresno, Eduard Portell i de Mora, Jordi Clotet Altarriba, Marcial Torra Roca, Jorge Antiche Garzón, Erika Balaguer Núñez, María de los Dolores Borrachero, Raúl Cantat Gaudin, Tristan Carrasco Martínez, José Manuel Casamiquela Floriach, Laia Castro Ginard, Alfred Farras Casas, Martí Julbe, Francesc Mor Crespo, Roger Castañeda Pons, Javier Bernardo González Vidal, Juan José Bartolomé Muñoz, Sergi Garralda Torre, Nora Jordi i Nebot, Carme |
Keywords: | Astrometria Estels variables Estels Cúmuls d'estels Astrometry Variable stars Stars Clusters of stars |
Issue Date: | 13-Mar-2019 |
Publisher: | EDP Sciences |
Abstract: | Context: The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G<21 mag. Aims: We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsating, eruptive, and cataclysmic variables, as well as on stars that exhibit variability that is due to rotation and eclipses. Methods: We describe the locations of variable star classes, variable object fractions, and typical variability amplitudes throughout the CaMD and show how variability-related changes in colour and brightness induce 'motions'. To do this, we use 22 months of calibrated photometric, spectro-photometric, and astrometric Gaia data of stars with a significant parallax. To ensure that a large variety of variable star classes populate the CaMD, we crossmatched Gaia sources with known variable stars. We also used the statistics and variability detection modules of the Gaia variability pipeline. Corrections for interstellar extinction are not implemented in this article. Results: Gaia enables the first investigation of Galactic variable star populations in the CaMD on a similar, if not larger, scale as was previously done in the Magellanic Clouds. Although the observed colours are not corrected for reddening, distinct regions are visible in which variable stars occur. We determine variable star fractions to within the current detection thresholds of Gaia. Finally, we report the most complete description of variability-induced motion within the CaMD to date. Conclusions: Gaia enables novel insights into variability phenomena for an unprecedented number of stars, which will benefit the understanding of stellar astrophysics. The CaMD of Galactic variable stars provides crucial information on physical origins of variability in a way that has previously only been accessible for Galactic star clusters or external galaxies. Future Gaia data releases will enable significant improvements over this preview by providing longer time series, more accurate astrometry, and additional data types (time series BP and RP spectra, RVS spectra, and radial velocities), all for much larger samples of stars. |
Note: | Reproducció del document publicat a: https://doi.org/10.1051/0004-6361/201833304 |
It is part of: | Astronomy & Astrophysics, 2019, vol. 623, num. A110 |
URI: | http://hdl.handle.net/2445/140649 |
Related resource: | https://doi.org/10.1051/0004-6361/201833304 |
ISSN: | 0004-6361 |
Appears in Collections: | Articles publicats en revistes (Física Quàntica i Astrofísica) |
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File | Description | Size | Format | |
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683592.pdf | 5 MB | Adobe PDF | View/Open |
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