Related papers: Be-star rotation: how close to critical?
We investigate the possible gravitational redshift values for boson stars with a self-interaction, studying a wide range of possible masses. We find a limiting value of $z_{lim} \simeq 0.687$ for stable boson star configurations. We compare…
The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally intensive problem, it is often useful to…
Massive stars may during their evolution reach the phase of critical rotation when the further increase in rotational speed is no longer possible. The ejection of matter in the equatorial region forms the gaseous outflowing disk, which…
We utilize the bulk viscosity of interacting strange quark matter to reevaluate the damping time scale. The presence of medium effect of bulk viscosity leads to a stronger damping of r-modes, which can be over an order of magnitude for…
Recent discovery of kilohertz quasi-periodic brightness oscillations of low mass X-ray binaries (LMXBs) has attracted attention to highly relativistic periodic motion near accreting neutron stars. Most models proposed so far involve…
We study the gravitational lensing by a Kerr-Sen Black Hole arising in heterotic string theory. A closed form expression for the bending angle of light in equatorial plane of Kerr-Sen Black Hole is derived as a function of impact parameter,…
KELT-9 b is an ultra hot Jupiter transiting a rapidly rotating, oblate early-A-type star in a polar orbit. We model the effect of rapid stellar rotation on KELT-9 b's transit light curve using photometry from the Transiting Exoplanet Survey…
We calculate the disk and boundary layer luminosities for accreting rapidly rotating neutron stars with low magnetic fields in a fully general relativistic manner. Rotation increases the disk luminosity and decreases the boundary layer…
Evolutionary models of fast-rotating stars show that the stellar rotational velocity may approach the critical speed. Critically rotating stars cannot spin up more, therefore they lose their excess angular momentum through an equatorial…
In this paper, we discuss the influence of the gravitational darkening effect on the emergent spectrum of a fast-rotating, flattened neutron star. Model atmosphere codes always calculate spectra of emergent intensities and fluxes emitted…
The light deflection of one component of a binary system due to the gravitational field of the other component is investigated. While this relativistic effect has not been observed thus far, the question arises that whether this effect…
The galactocentric rotation of the Solar system generates the systematic effect in proper motions known as 'secular aberration drift'. This tiny effect (about five microseconds per year) in the quasar proper motion can be measured by VLBI.…
In recent years the idea, first formulated many decades ago, that the Be phenomenon could be causally related to the duplicity of Be stars, has been repeatedly reconsidered from various perspectives. It is important, therefore, to have…
The majority of massive classical Be stars are thought to be binary interactions products. Their rapid rotation and often strong, variable, and emission-line dominated spectrum, make spectroscopic analysis challenging. Hence, robust binary…
Rotation plays a major role in the evolution of massive stars. A revised grid of stellar evolutionary tracks accounting for rotation has recently been released by the Geneva group and implemented into the Starburst99 evolutionary synthesis…
The critical inclination is of special interest in artificial satellite theory. The critical inclination can maintain minimal deviations of eccentricity and argument of pericentre from the initial values, and orbits at this inclination have…
One of the largest uncertainties in stellar structure and evolution theory is the transport of angular momentum in the stellar interiors. Asteroseismology offers a powerful tool for measuring the internal rotation frequencies of pulsating…
Contrary to the orthodox picture of planet formation resulting in a neatly ordered Solar System, exoplanet systems exhibit highly diverse orbits: short and long periods, circular and eccentric, well- and misaligned, and even retrograde…
Hot, massive stars (spectral types O and B) have extreme luminosities ($10^4 -10^6 L_\odot$) that drive strong stellar winds through UV line-scattering. Some massive stars also have disks, formed by either decretion from the star (as in the…
We investigate the ionization structure in the non-spherical winds and disks of B[e] stars. Especially the luminous B[e] supergiants seem to have outflowing disks which are neutral in hydrogen already close to the stellar surface. The…