This review provides an overview of recent advances in multi-wavelength and multi-
messenger observations of blazars, the current status of theoretical models for blazar …

Blazars are active galactic nuclei, which are powerful sources of radiation whose central
engine is located in the core of the host galaxy. Blazar emission is dominated by non …

In an effort to locate the sites of emission at different frequencies and physical processes
causing variability in blazar jets, we have obtained high time-resolution observations of BL …

Among active galactic nuclei, blazars show extreme variability properties. We here
investigate the case of the BL Lac object S4 0954+ 65 with data acquired in 2019–2020 by …

Various attempts have been made in the literature at describing the origin and the physical
mechanisms behind flaring events in blazars with radiative emission models, but detailed …

In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively
followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT …

Even with several thousand Fermi-Large Area Telescope (LAT) blazar detections, the γ-ray
emission mechanism is poorly understood. We explore correlated optical/γ-ray flux …

Active galactic nuclei come in many varieties. A minority of them are radio-loud, and exhibit
two opposite prominent plasma jets extending from the proximity of the supermassive black …

We present a polarization variability analysis of a sample of 26 γ-ray blazars monitored by
the Steward Observatory between 2008 and 2018 in the optical band. We investigate the …

We report on a recent multiband optical photometric and polarimetric observational
campaign of the blazar OJ 287 that was carried out during 2016 September–2017 …