Related papers: Non-radially pulsating stars as microlensing sourc…
We calculate the rotational broadening in the observed thermal spectra of neutron stars spinning at moderate rates in the Hartle-Thorne approximation. These calculations accurately account for the effects of the second-order Doppler boosts…
We consider the nonspherically decaying radiation field that is generated by a polarization current with a superluminally rotating distribution pattern in vacuum, a field that decays with the distance $\subP{R}$ from its source as…
Neutron stars in close binary systems have the potential to spin up to millisecond periods due to the accretion of matter and angular momentum from their low-mass companions. In later stages of this process, they sometimes start to swing…
The present work investigates the numerical evolution of linearized oscillations of non-rotating, spherically symmetric neutron stars within the framework of general relativity. We derive the appropriate equations using the (3+1)-formalism.…
The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star. Observational confirmation of this scenario may be challenging, but a…
We compare stellar photometric variability, as measured from Kepler light curves by Basri et al. (2011), with measurements of radial velocity (RV) root-mean-square (RMS) variations of all California Planet Search overlap stars. We newly…
Observations of thermal radiation from neutron stars allow one to measure the surface temperatures and confront them with cooling scenarios. Detection of gravitationally redshifted spectral lines can yield the mass-to-radius ratio. In the…
Pulse profile modelling via relativistic ray-tracing can constrain the system parameters of neutron stars, notably their mass and radius. Among these objects, accreting millisecond pulsars (AMPs) are promising targets, because they are…
The long-time photometric surveys in a few young open clusters allowed to identify the light variability in stars located on the HR diagram between the well defined $\delta$ Scuti variables and Slowly Pulsating B-type stars. Several objects…
Gravitational microlensing, in case of relevant finite source size effects, provides an unique tool for the study of stellar atmospheres through the enhancement of a characteristic polarization signal. Here, we consider a set of highly…
We have completed a high-resolution, high-signal-to-noise, spectroscopic survey of the northern members of the peculiar lambda Boo stars in order to investigate the frequency of the incidence of nonradial pulsation (NRP) in these…
Neutron stars are identified as pulsars, X-ray binary components, central objects of supernovae remnants, or isolated thermally emitting sources, and at distances beyond 120 pc. A population extrapolation suggests 10$^3$ objects within that…
X-ray pulsars experiencing extreme mass accretion rates can produce neutrino emission in the MeV energy band. Neutrinos in these systems are emitted in close proximity to the stellar surface and subsequently undergo gravitational bending in…
The mass of single neutron stars (NSs) can be measured using astrometric microlensing events. In such events, the center-of-light motion of a star lensed by a NS will deviate from the expected non-lensed motion and this deviation can be…
Characterization of microlensing planets requires modeling of observed light curves including many parameters. Studying the dependency of the pattern of light curves on the lensing parameters and the correlations between the parameters is…
It is expected that extreme mass accretion rate onto strongly magnetised neutron star results in appearance of accretion columns above stellar surface. For a distant observer, rotation of a star results in periodic variations of X-ray flux.…
We have shown previously that many of the properties of persistent accretion-powered millisecond pulsars can be understood if their X-ray emitting areas are near their spin axes and move as the accretion rate and structure of the inner disk…
The NASA Kepler mission is providing an unprecedented set of asteroseismic data. In particular, short-cadence lightcurves (~60s samplings), allow us to study solar-like stars covering a wide range of masses, spectral types and evolutionary…
Rotation is a critical physical process operating in the formation of Am stars. There is a strong correlation between low-velocity rotation and chemical peculiarity. However, the existence of many non-CP slow rotators challenges the…
The 76 frequencies determined from Kepler measurements of the A-type star KIC 9700322 can be understood in a rather simple way as the radial fundamental and first overtone radial modes, a nonradial \ell = 2 quintuplet, stellar rotation and…