Currently available information on fast variability of the X-ray emission from accreting
collapsed objects constitutes a complex phenomenology which is difficult to interpret. We …

According to the no-hair theorem, astrophysical black holes are uniquely described by their
masses and spins. An observational test of the no-hair theorem can be performed by …

If sufficiently irradiated by its central star, a protoplanetary disc falls into an equilibrium state
exhibiting vertical shear. This state may be subject to a hydrodynamical instability, the …

We found a possible~ 1 h quasi-periodic oscillation (QPO) in a~ 55 ks X-ray observation of
the narrow-line Seyfert 1 galaxy MCG–06–30–15 made with the XMM-Newton EPIC/pn …

The origin of chemically peculiar stars and nonzero eccentricity in evolved close binaries
have been long-standing problems in binary stellar evolution. Answers to these questions …

The transient Swift J1644+ 57 is believed to have been produced by an unlucky star
wandering too close to a supermassive black hole (BH) leading to a tidal disruption event …

We consider the interface between an accretion disk and a magnetosphere surrounding the
accreting mass. We argue that such an interface can occur not only with a magnetized …

In recent years, near-IR and X-ray flares have been detected from the Galaxy's central radio
point source, Sagittarius A*(Sgr A*), believed to be an~ 3× 10 6 M☉ supermassive black …

Quasi-periodic oscillations, often present in the power density spectrum of accretion disk
around black holes, are useful probes for the understanding of gravitational interaction in the …

The formation of planetesimals is a challenging problem in planet formation theory. A
prominent scenario for overcoming dust growth barriers is the gravitational collapse of …