Optical spectra (range 600-690 nm; resolution 6000) were obtained during the current outburst of this black hole binary on July 4.65-4.75 UT with the Siding...
A single 30 min high-resolution spectrum of the optical counterpart to the black hole candidate XTE J1817-330 (ATEL #714, #733) was acquired with the MIKE...
Optical/IR flux fading rapidly in GX 339-4: OIR jet quenching
The transient black hole candidate GX 339-4 is currently softening in X-ray, making a transition out of the hard state (ATel #2545). We are monitoring the...
Orphan optical flare as SOSS emission afterglow, localization in time
We report on MASTER optical observations of an afterglow-like optical and X-ray transient AT2021lfa/ZTF21aayokph. We detected the initial steady brightening of...
Phase-dependent Study of Near-infrared Disk Emission Lines in LB-1
The mass, origin, and evolutionary stage of the binary system LB-1 have been intensely debated, following the claim that it hosts an ∼70M ☉ black hole, in stark...
Populations of evolved massive binary stars in the Small Magellanic Cloud: I. Predictions from detailed evolution models
Context. The majority of massive stars are born with a close binary companion. How this affects their evolution and fate is still largely uncertain, especially...
Populations of evolved massive binary stars in the Small Magellanic Cloud: II. Predictions from rapid binary evolution
Context. Massive star evolution plays a crucial role in astrophysics; however, its study is subject to large uncertainties. This problem becomes more severe by...