Related papers: Is Her X-1 a strange star?
Motivated by the recent suggestions that very massive pulsar (PSR J0952-0607) and very light compact object (HESS J1731-347) exist, in this article, we revisit the possibility of such objects being strange stars instead of the standard…
We prove a curious identity for the Bernoulli numbers.
Some early-type stars are detectable radio emitters; their spectra can present both thermal and non-thermal contributions. Here I review the public radio data on OB stars, focusing on the non-thermal sources. The analysis of the statistical…
We review and update the current status of the observed anomalies in stellar cooling and their interpretation in terms of axions and axion like particles.
We report optical and IR observations of the ASCA X-ray pulsar system AX J0051-733. The relationship between the X-ray source and possible optical counterparts is discussed. Long term optical data from over 7 years are presented which…
Perspectives article on J. Xiong et al., Science 350, 413 (2015).
We list a few things that we do not understand about stars and that most people ignore. These are all hard problems. We can learn more cosmology by working on them to reduce the systematic errors they introduce than by trying to derive…
We present high-quality spectra of the majority of stars that have been classified as Oe and find that their published spectral types are generally too early, most likely due to infilling of HeI lines. As a matter of fact, all stars…
This paper discusses several most intruigung astrophysical implications connected with the possible absolute stability of strange quark matter.This is followed by a discussion of two astrophysical signals that may point at the existence of…
The general statement that strange stars cool more rapidly than neutron stars is investigated in greater detail. It is found that the direct Urca process could be forbidden not only in neutron stars but also in strange stars. If so, strange…
The AAVSO lightcurve data of the irregularly pulsating star AC Herculis of the RV Tau class are analysed. The lightcurve is shown to be incompatible with a periodic, or even multiperiodic pulsation, even if allowance is made for evolution.…
Using observations of X-ray pulsar Her X-1 by the Imaging X-ray Polarimetry Explorer, we report on a highly significant ($>17\sigma$) detection of the polarization signal from an accreting neutron star. The observed degree of the linear…
It is argued that apart from the well known dependence of the Am phenomenon on the mass, age (effective temperature, gravity) and rotation there is also a complex dependence on the orbital parameters in binary systems. This is why the…
Use of the brightest stars in galaxies as a distance indicator and claims that the method supports the `short' distance scale are examined. Data from several different observational programmes are brought together for the first time with a…
Current study highlights the physical characteristics of charged anisotropic compact stars by exploring some exact solutions of modified field equations in $f(R,G)$ gravity. A comprehensive analysis is performed from the obtained solutions…
Context: Recently, Doroshenko and collaborators reported a very low-mass compact star, a Central Compact Object named XMMU J173203.3-344518 inside the supernova remnant HESS J1731-347. Its tiny mass is at odds with all calculations of…
Possible interpretations of the HERA large-Q^2 data are reviewed briefly. The possibility of statistical fluctuations cannot be ruled out, and it seems premature to argue that the H1 and ZEUS anomalies are incompatible. The data cannot be…
In this work, we made an extensive study about the possible presence of anisotropies in strange stars. To accomplish this task, we use three different configurations for the strange matter: the unpaired matter, a two-flavor super-conducting…
A remarkably precise observational relation for pulse core component widths of radio pulsars is used to derive stringent limits on pulsar radii, strongly indicating that pulsars are strange stars rather than neutron stars. This is achieved…
This paper has been withdrawn by the author due to the presented idea is wrong.