Related papers: Is Her X-1 a strange star?

This paper is a refutation of two researches by A. N. Sazonov on HZ Her and V1341 Cyg published in the Astronomy Reports (Vol. 55, p.p.142 and 230) in 2011. We analyzed his photometry along with other data collected in the literature and…

Both neutron stars and strange stars are capable of supporting fast rotations observed in pulsars. On the basis of this it has been argued that some of the pulsars could be strange stars. We investigate whether strange stars can sustain…

We derive an equation of state (EOS) for strange matter, starting from an interquark potential which (i) has asymptotic freedom built into it, (ii) shows confinement at zero baryon density and deconfinement at high density and (iii) gives a…

We propose a spherically symmetric and anisotropic model for strange quark stars within the framework of MIT Bag model. Though the model is found to comply with all the physical requirements of a realistic star satisfying a strange matter…

Recently there is a suggestion about the star RXJ1856.5$-$3754, being a possible candidate for quark star. While from the estimates of the radiation radius, given by the authors, it does not seem to fit with any of the known models for such…

RX J1856.5-3754 has been proposed as a strange star candidate due to its very small apparent radius measured from its X-ray thermal spectrum. However, its optical emission requires a much larger radius and thus most of the stellar surface…

In this talk we discuss possible signatures for the existence of strange quark matter stars (strange stars).

Discovery of binary systems among RR Lyrae stars belongs to challenges of present astronomy. So far, none of classical RR Lyrae stars was clearly confirmed that it is a part of an eclipsing system. For this reason we studied two RR Lyrae…

In the attempt to shed new light on the lambda Boo phenomenon we analyzed the astrometric, photometric and spectroscopic characteristics of stars out of a list of recently selected lambda Boo candidates. We show that the class is still…

It is believed that pulsars are neutron stars or strange stars with crusts. However we suggest here that pulsars may be bare strange stars (i.e., strange stars without crust). Due to rapid rotation and strong emission, young strange stars…

A pedagogical overview of strange quark matter and strange stars is presented. After a historical notation of the research and an introduction to quark matter, a major part is devoted to the physics and astrophysics of strange stars, with…

Motivated by trying to understand the absence of spectral lines in the thermal components of the X-ray compact sources observed recently by Chandra or XMM, we propose that these sources could be simply bare strange stars. The formation,…

One of the most important questions in the study of compact objects is the nature of pulsars, including whether they are composed of $\beta$-stable nuclear matter or strange quark matter. Observations of the newly discovered millisecond…

Here we investigate the possibility that the asteroid 1I/2017 U1 actually is a Solar System object, currently expelled from the Solar System by the recent encouter with a Solar System planet. We show that this possibility is extremely…

It is proposed that the `bare' strange matter stars might not be bare, and radio pulsars might be in fact `bare' strange stars. As strange matter stars being intensely magnetized rotate, the induced unipolar electric fields would be large…

I discuss the X-ray observations of Be stars, and how their properties compare to non-emission B stars. I focus on several specific stars that show high flux levels and variability but also report on several interesting survey results. The…

The reason, we need three terms of `strange', `bare', and `solid' before quark stars, is presented concisely though some fundamental issues are not certain. Observations favoring these stars are introduced.

Recently, astronomers discovered unusual Einstein cross images of the galaxy HerS-3, which feature a bright central spot. Motivated by studies of images produced by regular stars, it has been proposed that optical appearances caused by…

We report on the identification of the optical counterpart to Star1, the exotic object serendipitously discovered by Deutsch et al. in the core of the Galactic globular cluster NGC 6624. Star1 has been classified by Deutsch et al. as either…

Her X-1 is an accreting neutron star in an intermediate-mass X-ray binary. Like low-mass X-ray binaries (LMXBs), it accretes via Roche-lobe overflow, but similar to many high-mass X-ray binaries containing a neutron star, Her X-1 has a…