Related papers: Are disk in dwarf novae during their superoutburst…
We propose a theoretical explanation of absorption/emission line systems in classical novae based on a fully self-consistent nova explosion model. We found that a reverse shock is formed far outside the photosphere ($\gtrsim 10^{13}$ cm)…
The fact that the majority of the youngest radio pulsars are surrounded by expanding supernova remnants is strong evidence that neutron stars are produced in the supernovae of massive stars. In many cases, the pulsar appears significantly…
Be stars are rapidly spinning B stars surrounded by an outflowing disc of gas in Keplerian rotation. Be star/X-ray binary systems contain a Be star and a neutron star. They are found to have non-zero eccentricities and there is evidence…
Instabilities and strong dynamical interactions between multiple giant planets have been proposed as a possible explanation for the surprising orbital properties of extrasolar planetary systems. In particular, dynamical instabilities seem…
We study the distribution of orbital eccentricities of stars in thick disks generated by the heating of a pre-existing thin stellar disk through a minor merger (mass ratio 1:10), using N-body/SPH numerical simulations of interactions that…
We present multi-epoch, time-resolved optical spectroscopic observations of the dwarf nova HT Cas, obtained during 1986, 1992, 1995 and 2005 with the aim to study the properties of emission structures in the system. We determined that the…
The most puzzling property of the extrasolar planets discovered by recent radial velocity surveys is their high orbital eccentricities, which are very difficult to explain within our current theoretical paradigm for planet formation.…
Millisecond pulsars (MSPs) orbiting helium white dwarfs (WDs) in eccentric orbits challenge the established binary evolution paradigm that predicts efficient orbital circularization during the mass transfer episode that spins up the pulsar.…
Radiation pressure-dominated accretion disks are predicted to exhibit strong density inhomogeneities on scales much smaller than the disk scale height, due to the nonlinear development of photon bubble instability. Radiation would escape…
We present photometric observations of the dwarf nova 1RXS J053234.9+624755. We performed a detailed analysis of the superoutburst that occurred in August 2009. We found the superhump period to be P_sh=0.057122(14)days. Based on the O-C…
Compact object binaries formed from dynamics interactions will generically have non-zero orbital eccentricity. The gravitational waves from such binaries can change drastically depending on how large the eccentricity is, ranging from…
Observations of the Galactic Centre show evidence of disc-like structures of very young stars orbiting the central super-massive black hole within a distance of a few 0.1 pc. While it is widely accepted that about half of the stars form a…
We present the 45-yr record of EX Hya's lightcurve and discuss the characteristics of its 15 observed outbursts. We then concentrate on the 1998 outburst, reporting the first outburst X-ray observations. We discover an X-ray beat-cycle…
The unprecedented sky coverage and observing cadence of the All-Sky Automated Survey for SuperNovae (ASAS-SN) has resulted in the discovery and continued monitoring of a large sample of Galactic transients. The vast majority of these are…
We report the discovery of forty erupting cataclysmic variable stars in the OGLE-III Galactic disk fields: seventeen objects of U Gem type, four of Z Cam type, and nineteen stars showing outbursts and superoutbursts typical for SU UMa type…
Imaging of debris disks has found evidence for both eccentric and offset disks. One hypothesis is that these provide evidence for massive perturbers that sculpt the observed structures. One such disk was recently observed in the far-IR by…
Quark-novae leave behind quark stars with a surrounding metal-rich fall-back (ring-like) material. These compact remnants have high magnetic fields and are misconstrued as magnetars; however, several observational features allow us to…
Stellar scattering off of orbiting or transient clumps is shown to lead to the formation of exponential profiles in both surface density and velocity dispersion in a two-dimensional non-self gravitating stellar disk with a fixed halo…
Nova explosions occur on accreting white dwarfs. A thermonuclear runaway in the H-rich accreted envelope causes its ejection without destroying the white dwarf, and an increase in the luminosity by several magnitudes. Accretion is…
We consider the possibility that an infalling bulge core or stellar cluster could form an eccentric disk, following tidal disruption by a massive black hole in the center of a galaxy. As a function of central black hole mass, we constrain…