Related papers: Are disk in dwarf novae during their superoutburst…
The orbital eccentricity distribution of exoplanets is shaped by a combination of dynamical processes, reflecting both formation conditions and long-term evolution. Probing the orbital dynamics of planets in the kinematic thin and thick…
Most extrasolar planets are observed to have eccentricities much larger than those in the solar system. Some of these planets have sibling planets, with comparable masses, orbiting around the same host stars. In these multiple planetary…
We consider accretion onto the white dwarfs in cataclysmic variables in relation to nova eruptions, dwarf nova outbursts, hibernation and non-radial oscillations.
WZ Sge-type dwarf novae form one of the most intriguing classes of compact accreting binaries. They are recognized as the most evolved population of hydrogen-rich cataclysmic variables. Yet they exhibit energetic disk-powered outbursts with…
The nucleus of M31 may be a thick eccentric disk, composed of stars traveling on nearly Keplerian orbits around a black hole or other dark compact object. This hypothesis reproduces most of the features seen in HST photometry of the center…
Stellar scattering off irregularities in a galaxy disk has been shown to make an exponential radial profile, but no fundamental reason for this has been suggested. Here we show that exponentials are mathematically expected from random…
Nova outbursts are the result of strong thermonuclear runaways on the surface of a white dwarf accreting Hydrogen-rich material from a small mass companion. These giant explosions cause the star to increase its brightness by hundreds of…
A theory is developed for the dynamics of eccentric perturbations $[\propto \exp(\pm i\phi)]$ of a disk galaxy residing in a spherical dark matter halo and including a spherical bulge component. The disk is represented as a large number $N$…
The high eccentricities of the known extrasolar planets remain largely unexplained. We explore the possibility that eccentricities are excited in the outer parts of an extended planetary disk by encounters with stars passing at a few…
There are several peculiar long-period dwarf-nova like objects, which show rare, low-amplitude outbursts with highly ionized emission lines. 1SWASP J162117$+$441254, BD Pav, and V364 Lib belong to this kind of objects. Some researchers even…
We follow the changes in the structure of the accretion disk of the dwarf nova V2051 Oph along two separate outbursts in order to investigate the causes of its recurrent outbursts. We apply eclipse mapping techniques to a set of light…
We examine the efficiency with which supernova-enriched gas may be ejected from dwarf disk galaxies, using a methodology previously employed to study the self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies that…
We present a new mechanism of generating large planetary eccentricities. This mechanism applies to planets within the inner cavities of their companion protoplanetary disks. A massive disk with an inner truncation may become eccentric due…
The 10th recorded outburst of the recurrent eclipsing nova USco was observed simultaneously in X-ray, UV, and optical by XMM-Newton on days 22.9 and 34.9 after outburst. Two full passages of the companion in front of the nova ejecta were…
Orbits of known extrasolar planets that are located outside the tidal circularization regions of their parent stars are often substantially eccentric. By contrast, planetary orbits in our Solar System are approximately circular, reflecting…
The non-axisymmetric features observed in the discs of dwarf novae in outburst are usually considered to be spiral shocks, which are the non-linear relatives of tidally excited waves. This interpretation suffers from a number of problems.…
While accreting through a circumstellar disk, young stellar objects are observed to undergo sudden and powerful accretion events known as FUor or EXor outbursts. Although such episodic accretion is considered to be an integral part of the…
Sokoloski et al (2008) have recently reported evidence that the recurrent nova RS Ophiuchi produced a pair of highly collimated radio jets within days of its 2006 outburst. This suggests that an accretion disc must be present during the…
Fluctuations during a prolonged maximum have been observed in several nova eruptions, although it is not clear, and can not be deduced directly from observations, if the phenomenon is an actual physical reaction to some mechanism…
Can a disk orbiting a central body be eccentric, when the disk feels its own self-gravity and is pressureless? Contradictory answers appear in the literature. We show that such a disk can be eccentric, but only if it has a sharply truncated…