Study of short period variables and small amplitude periodic variables

Abstract

Abstract. Our goal is to assess Gaia's performance on the period recovery of short period (p < 2 hours) and small amplitude variability. To reach this goal first we collected the properties of variable stars that fit the requirements described above. Then we built a database of synthetic light-curves with short period and low amplitude variability with time sampling that follows the Gaia nominal scanning law and with noise level corresponding to the expected photometric precision of Gaia. Finally we performed period search on the synthetic light-curves to obtain period recovery statistics. This work extends our previous period recovery studies to short period variable stars which have nonstationary Fourier spectra.

The Variability Processing and Analysis of the Gaia mission

“…These latter algorithms ensure variability detection in cases where general variability tests are not sufficient and in addition derive some parameters specific to the type of variability. The cases treated by such specific algorithms are: short time-scales (Varadi et al, 2011), small amplitude periodic variables, exo-planetary transits (Tingley, 2011;Dzigan & Zucker, 2012, solar (magnetic) variables (Distefano et al, 2012).…”

Prediction of astrometric microlensing events during theGaiamission

“…At the end of the Gaia mission the combined accuracy, which is not relevant for our study, varies between ∼5 and 200 µas depending on the stellar brightness and the actual number of measurements (de Bruijne 2009). The photometric precision for a single measurement will be ∼1 to 20 millimag (Varadi et al 2011;Mignard 2011;Eyer & Figueras 2003) and the photometric accuracy reached at the end of the mission will amount to ∼0.1 to 2 millimag for stars of brightness 10 to 20 mag (Eyer & Figueras 2003;Perryman et al 2001;Varadi et al 2011), respectively. In this paper we selected astrometric microlensing candidates during the Gaia mission. We explore the possibility that Gaia can measure the resulting centroid shift trajectories.…”