Related papers: Gaia and Variable Stars
We take advantage of the Gaia data release 2 to present 275 and 1,774 ultraviolet luminous stars in the FUV and the NUV. These stars are 5$\sigma$ exceeding the centers of the reference frame that is built with over one million UV stars in…
Measurements of [Fe/H] and radial velocity are presented for 89 RR Lyrae (RRL) candidates within 6 kpc of the Sun. After removal of two suspected non-RRL, these stars were added to an existing database, which yielded 464 RRL with [Fe/H] on…
We analyzed photometry for the up-to-date collection of the first-overtone RR Lyrae stars (RRc; 11415 stars) and double-mode RR Lyrae stars (RRd; 148 stars) towards the Galactic bulge from the Optical Gravitational Lensing Experiment. We…
One of the novelties of the Gaia-DR3 with respect to the previous data releases is the publication of the multiband light curves of about 1 million AGN. The goal of this work was the creation of a catalogue of variable AGN, whose selection…
Globular clusters are both primary fossils of galactic evolution and formation and are ideal laboratories for constraining the evolution of low-mass and metal-poor stars. RR Lyrae and type II Cepheid variables are low-mass, radially…
We describe two ground based observing campaigns aimed at building a grid of approximately 200 spectrophotometric standard stars (SPSS), with an internal ~1% precision and tied to Vega within ~3%, for the absolute flux calibration of data…
We construct from Gaia eDR3 an extensive catalog of spatially resolved binary stars within $\approx$ 1 kpc of the Sun, with projected separations ranging from a few au to 1 pc. We estimate the probability that each pair is a chance…
Context: Many if not most planetary nebulae (PNe) are now thought to be the outcome of binary evolutionary scenarios. However only a few percent of PNe in the Milky Way are known to host binary systems. The high precision repeated observing…
The Galactic center (GC) is the densest region of the Milky Way. Variability surveys towards the GC potentially provide the largest number of variable stars per square degree within the Galaxy. However, high stellar density is also a…
Gaia DR3 provides >181, 000 radial velocity solutions for single-lined spectroscopic binaries (SB1s) which can be used to search for non-interacting compact object+star binary candidates by selecting systems with large mass functions. We…
We present a novel method to detect variable astrophysical objects and transient phenomena using anomalous excess scatter in repeated measurements from public catalogs of Gaia DR2 and Zwicky Transient Facility (ZTF) DR3 photometry. We first…
[ABRIDGED] $\omega$ Centauri (NGC 5139) contains large numbers of variable stars of different types and, in particular, more than a hundred RR Lyrae stars. We have conducted a variability survey of $\omega$ Cen in the NIR, using ESO's 4.1m…
In an earlier work, we demonstrated the effectiveness of Bayesian neural networks in estimating the missing line-of-sight velocities of Gaia stars, and published an accompanying catalogue of blind predictions for the line-of-sight…
Classical Cepheids (CCs) in Galactic open clusters (OCs) provide essential observational constraints for calibrating the period-age relation (PAR) and the period-Wesenheit relation (PWR) of CCs. However, distant and long-period OC Cepheids…
We describe the preliminary results of a ground-based observing campaign aimed at building a grid of approximately 200 spectro-photometric standard stars (SPSS), with an internal $\simeq 1$\% accuracy (and sub-percent precision), tied to…
Passing stars may play an important role in the evolution of our solar system. We search for close stellar encounters to the Sun among all 7.2 million stars in Gaia-DR2 that have six-dimensional phase space data. We characterize encounters…
We present some results of long term studies of pulsating stars conducted in the course of the OGLE and Araucaria projects. In particular very scarce eclipsing binaries containing pulsating stars are discussed. Such systems provide a unique…
We search for the fastest stars in the subset of stars with radial velocity measurements of the second data release (DR2) of the European Space Agency mission Gaia. Starting from the observed positions, parallaxes, proper motions, and…
The latest Gaia Focused Product Release (FPR) provided variability information for $\sim$1000 long-period red giant binaries, the largest sample to date of this binary type having both photometric and spectroscopic time series observations.…
From the Fourier analysis of the catalogue of ~200,000 variable candidates in the OGLE-II Galactic fields, we found a sample of about 230 short-period low-amplitude variable stars. From their position in the colour-magnitude diagram and the…