Related papers: Short timescale variables in the Gaia era: detecti…

In Dai et al. (2016) we developed a formalism for computing variance images from standard, interferometric radio images containing time and frequency information. Variance imaging with future radio continuum surveys allows us to identify…

The recent long look X-ray observations of TeV blazars have revealed many important new features concerning their time variability. In this paper, we suggest a physical interpretation for those features based on the framework of the…

We report observations and analysis of flux monitoring of Sagittarius A* at 3-mm wavelength using the OVRO millimeter interferometer over a period of eight days (2002 May 23-30). Frequent phase and flux referencing (every 5 minutes) with…

We use data from a recent long ASCA observation of the Narrow Line Seyfert 1 Ark 564 to investigate in detail its timing properties. We show that a thorough analysis of the time series, employing techniques not generally applied to AGN…

We analyze the properties of quasar variability using repeated SDSS imaging data in five UV-to-far red photometric bands, accurate to 0.02 mag, for 13,000 spectroscopically confirmed quasars. The observed time lags span the range from 3…

Our paper presents new methods for finding and testing of weak periodic variability of stellar objects developed for the purpose of detecting expected regular light variations of magnetic chemically peculiar (mCP) candidates in the Large…

We present photometric light curves for a sample of 21 ultra cool M and L dwarfs in the field and in the young open clusters sigma Orionis and the Pleiades. Evidence for variability with RMS amplitudes (in the I band) of 0.01 to 0.055…

Gaia DR3 contains 1.8 billion sources with G-band photometry, 1.5 billion of which with BP and RP photometry, complemented by positions on the sky, parallax, and proper motion. The median number of field-of-view transits in the three…

Continuously time variable sources are often characterized by their power spectral density and flux distribution. These quantities can undergo dramatic changes over time if the underlying physical processes change. However, some changes can…

The ESA Gaia mission uses two telescopes to create the most ambitious survey of the Galaxy. The angle between them must be known with exquisite precision and accuracy. An interferometer: the Basic Angle Monitoring system measures its…

Aims: During its all-sky survey phase, the eROSITA X-ray telescope onboard SRG scans through the ecliptic poles every 4 hours. This extensive data set of long-duration, frequent, and consistent observations of thousands of X-ray sources is…

The astrometric space mission Gaia is expected to detect a large number of brown dwarf binary systems with close orbits and determine astrometric orbit solutions. This will provide key information for the formation and evolution of brown…

Understanding and anticipating vulnerability-related activity is a major challenge in cyber threat intelligence. This work investigates whether vulnerability sightings, such as proof-of-concept releases, detection templates, or online…

Future space and ground-based survey programmes will produce an impressive amount of photometric data. The GAIA space mission will map the complete sky down to mag V=20 and produce time series for about 1 billion stars. Survey instruments…

We present a comprehensive temporal and spectral analysis of a few blazars using multi-wavelength observations. Rapid flux variations are quantified via the doubling/halving timescale method, revealing the shortest variability timescales of…

We present a method for the detection and characterization of random changes in the flux from $\gamma$-ray pulsars on sub-hour timescales, much shorter than variations that can be accessed using direct flux measurements. Flux variations are…

Many astronomical phenomena, including Fast Radio Bursts and Soft Gamma Repeaters, consist of brief, separated, seemingly aperiodic events. The intervals between these events vary randomly, but there are epochs of greater activity, with…

Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae,…

We present a new and simple technique for selecting extensive, complete and pure quasar samples, based on their intrinsic variability. We parametrize the single-band variability by a power-law model for the light-curve structure function,…

The ESA Gaia mission is a 10+ year astrometric whole-sky scan, demanding consistent data quality over the whole timespan of operations Aims. The Gaia First Look (FL) is a system whose aim is monitoring the data quality to identify problems,…