We study the K-correction for the case of emission lines formed in the X-ray-illuminated atmosphere of a Roche lobe-filling star. We compute the K-correction as...

The black hole transient V404 Cygni exhibited a bright outburst in June 2015 that was intensively followed over a wide range of wavelengths. Our team obtained...

We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of...

EX Lup is the prototype of the EXor class of eruptive young stars. These objects show optical outbursts which are thought to be related to runaway accretion...

We present the results of our quasi-simultaneous radio, submm, infrared, optical and X-ray study of the Galactic black hole candidate X-ray binary MAXI J1836...

We use multi-wavelength microlensing measurements of a sample of 10 image pairs from 8 lensed quasars to study the structure of their accretion disks. By using...

We have measured the brightness of the optical counterpart of the black hole X-ray binary Nova Sco 1994 (GRO J1655-40) during 40 nights between 1995 May 3 and...

We present the first simultaneous spectral energy distribution (SED) of M87 core at a scale of 0.4 arcsec ( ˜ 32 pc) across the electromagnetic spectrum. Two...

MAXI J1807+132 is an X-ray transient discovered during the decay of an outburst in 2017. We present optical and X-ray monitoring of the source over more than...