Pulsating star research and the Gaia revolution

In this article we present an overview of the ESA Gaia mission and of the unprecedented impact that Gaia will have on the field of variable star research. We summarise the contents and impact of the first Gaia data release on the description of variability phenomena, with particular emphasis on pulsating star research. The Tycho-Gaia astrometric solution, although limited to 2.1 million stars, has been used in many studies related to pulsating stars. Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series have been released. Finally we present the plans for the ongoing study of variable phenomena with Gaia and highlight some of the possible impacts of the second data release on variable, and specifically, pulsating stars.Comment: 12 pages, 4 figures, proceedings for the 22nd Los Alamos Stellar Pulsation Conference Series Meeting "Wide field variability surveys: a 21st-century perspective", held in San Pedro de Atacama, Chile, Nov. 28 - Dec. 2, 201

Short time-scale variables in the gaia era: detection and characterization by structure function analysis

We investigate the capabilities of the ESA Gaia mission for detecting and characterizing short time-scale variability, from tens of seconds to a dozen hours. We assess the efficiency of the variogram analysis, for both detecting short time-scale variability and estimating the underlying characteristic time-scales from Gaia photometry, through extensive light-curve simulations for various periodic and transient short time-scale variable types. We show that, with this approach, we can detect fast periodic variability, with amplitudes down to a few millimagnitudes, as well as some M dwarf flares and supernovae explosions, with limited contamination from longer time-scale variables or constant sources. Time-scale estimates from the variogram give valuable information on the rapidity of the underlying variation, which could complement time-scale estimates from other methods, like Fourier-based periodograms, and be reinvested in preparation of ground-based photometric follow-up of short time-scale candidates evidenced by Gaia. The next step will be to find new short time-scale variable candidates from real Gaia data, and to further characterize them using all the Gaia information, including colour and spectrum

Pulsating star research and the Gaia revolution

In this article we present an overview of the ESA Gaia mission and of the unprecedented impact that Gaia will have on the field of variable star research. We summarise the contents and impact of the first Gaia data release on the description of variability phenomena, with particular emphasis on pulsating star research. The Tycho-Gaia astrometric solution, although limited to 2.1 million stars, has been used in many studies related to pulsating stars. Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series have been released. Finally we present the plans for the ongoing study of variable phenomena with Gaia and highlight some of the possible impacts of the second data release on variable, and specifically, pulsating stars