Related papers: MASTER optical polarization variability detection …
We present results of optical polarization observations performed with the MASTER robotic net for three types of objects: gamma-ray bursts, supernovae, and blazars. For the Swift gamma-ray bursts GRB100906A, GRB110422A, GRB121011A,…
We present a spectrophotometric study of short-term optical variability in the quiescent black hole X-ray transient V404 Cyg focusing on two nights of Halpha spectroscopy. We find significant variability, with both the Halpha line and the…
We present a serendipitous multiwavelength campaign of optical photometry simultaneous with Integral X-ray monitoring of the 2015 outburst of the black hole V404 Cyg. Large amplitude optical variability is generally correlated with X-rays,…
We present optical multi-colour photometry of V404 Cyg during the outburst from December, 2015 to January, 2016 together with the simultaneous X-ray data. This outburst occurred less than 6 months after the previous outburst in June-July,…
Our simultaneous three-colour ($BVR$) polarimetric observations of the low-mass black hole X-ray binary V404 Cyg show a small but statistically significant change of polarization degree ($\Delta p \sim 1$ per cent) between the outburst in…
We present optical and near-IR linear polarimetry of V404 Cyg during its 2015 outburst and in quiescence. We obtained time resolved r'-band polarimetry when the source was in outburst, near-IR polarimetry when the source was near quiescence…
We present new spectroscopic and polarimetric observations of the gravitational lens SDSS J1004+4112 taken with the 6m telescope of the Special Astrophysical Observatory (SAO, Russia). In order to explain the variability that is observed…
After 25 years of quiescence, the microquasar V404 Cyg entered a new period of activity in June 2015. This X-ray source is known to undergo extremely bright and variable outbursts seen at all wavelengths. It is therefore an object of prime…
The occurrence of low-amplitude flux variations in blazars on hourly timescales, commonly known as microvariability, is still a widely debated subject in high-energy astrophysics. Several competing scenarios have been proposed to explain…
We present a spectrophotometric study of short-term optical variability in the quiescent black hole X-ray transient V404 Cyg. This includes two nights of high time-resolution Halpha spectroscopy with which we resolve much of the…
In 2022 the BL Lac object S4 0954+65 underwent a major variability phase, reaching its historical maximum brightness in the optical and $\gamma$-ray bands. We present optical photometric and polarimetric data acquired by the Whole Earth…
We present the result of near-infrared and optical observations of the BL Lac object S5 0716$ + $714 carried out by the KANATA telescope. S5 0716$ + $714 has both a long term high-amplitude variability and a short-term variability within a…
The results of 8-year R-band photopolarimetric data of blazar Mrk 421 collected from February 2008 to May 2016 are presented, along with extensive multiwavelength observations covering from radio to TeV $\gamma$-rays around the flares…
An 11-day monitoring campaign in late 2005 reveals clear correlation in polarization between the optical emission and the region of the intensity peak (the "pseudocore") at the upstream end of the jet in 43 GHz Very Long Baseline Array…
We conducted the first long-term (75 days) X-ray monitoring of the black hole low mass X-ray binary V404 Cyg, with the goal of understanding and characterizing its variability during quiescence. The X-ray light curve of V404 shows several…
The transient optical source MASTER OT J072007.30+451611.6 has been recently discovered and proposed as a peculiar polar with an unusually high amplitude of the orbital brightness variation in the optical of $\sim$3 mag. To clarify its…
We report the discovery of variability in the linear polarization from the Galactic Center black hole source, Sagittarius A*. New polarimetry obtained with the Berkeley-Illinois-Maryland Association array at a wavelength of 1.3 mm shows a…
We present a multiwavelength analysis of the simultaneous optical and X-ray light curves of the microquasar V404 Cyg during the June 2015 outburst. We have performed a comprehensive analysis of all the INTEGRAL/IBIS, JEM-X, and OMC…
The quasar-type blazar 4C 38.41 (B3 1633+382) experienced a large outburst in 2011, which was detected throughout the entire electromagnetic spectrum. We present the results of low-energy multifrequency monitoring by the GASP project of the…
Blazars are known for their extreme variability across the electromagnetic spectrum. Variability at very short timescales can push the boundaries between competing models offering us much needed discriminating power. This is particularly…