相关论文: Is Her X-1 a strange star?

Using a realistic equation of state (EOS) of strange quark matter, namely, the modified bag model, and considering the constraints to the parameters of EOS by the observational mass limit of neutron stars, we study the r-mode instability…

The nature of the 5-12 s "anomalous" X-ray pulsars remains a mystery. Among the models that have been proposed to explain the properties of AXPs, the most likely ones are: (1) isolated accreting neutron stars evolved from the…

This letter follows a recent claim that the Hipparcos parallax for Polaris could be too small by 2.5 mas. It examines in detail the Hipparcos epoch astrometric data for Polaris, as well as the viability of other observations that were put…

Mira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years of polarization measurements for…

Before the age of modern photographic and CCD observations alpha Cassiopeiae was labelled as a variable star, though this variability has not been seen with modern instrumentation. We present an analysis of 3 years of high precision…

B[e] stars are among the most peculiar objects in the sky. This spectral type, characterised by allowed and forbidden emission lines, and a large infrared excess, does not represent an homogenous class of objects, but instead, a mix of…

The calculations of Guang-Wen Ma's recent Letter [Phys.Lett. A239, (1998) 209] contain an easily detectable error which makes his conclusions irrelevant.

The magnetar model and a solid quark star model for anomalous X-ray pulsars/soft gamma-ray repeaters (AXPs/SGRs) are discussed. Different manifestations of pulsar-like stars are speculated to be due to both their nature (e.g., mass and…

We identify the optical counterpart of the ultraluminous X-ray source (ULX) NGC 1313 X-1 and discuss constraints on its physical nature from multiband optical spectra. There is a single object on Hubble Space Telescope (HST) images within…

We investigate the stability of strange quark matter and the properties of the corresponding strange stars, within a wide range of quark mass scaling. The calculation shows that the resulting maximum mass always lies between 1.5 solor mass…

In recent years, the stars of the Of?p category have revealed a wealth of peculiar phenomena: varying line profiles, photometric changes, and X-ray overluminosity are only a few of their characteristics. Here we review their physical…

Most types of massive stars display X-ray emission that is affected by the properties of their stellar winds. Single non-magnetic OB stars have an X-ray luminosity that scales with their bolometric luminosity and their emission is thought…

Imagine we could do asteroseismology of large samples of OB-type stars by using just one spectrum per target. That would be great! But this is probably a crazy and stupid idea. Or maybe not. Maybe we have the possibility to open a new…

We report the results of H_alpha imaging and UV spectroscopy with the Hubble Space Telescope of the hot post-AGB star ZNG 1 in M 5 and its suspected planetary nebula.

The ''Anomalous X-ray Pulsars'' (AXPs) are a small group of X-ray pulsars characterized by periods in the 5-10 s range and by the absence of massive companion stars. There are now 7 possible members of this class of objects. We review…

Recent observations of Her X-1 with NuSTAR and INTEGRAL in 2016 have provided evidence that the 20-year decay of the cyclotron line energy found between 1996 and 2015 has ended and that an inversion with a new increase, possibly similar to…

Recent achievements of bare strange stars are briefly reviewed. A nascent protostrange star should be bare because of strong mass ejection and high temperature after the supernova detonation flame, and a crust can also hardly form except…

We find that in general relativity slow down of the pulsar rotation due to the magnetodipolar radiation is more faster for the strange star with comparison to that for the neutron star of the same mass. Comparison with astrophysical…

The interest in studying relativistic compact objects play an important role in modern astrophysics with an aim to understand several astrophysical issues. It is therefore natural to ask for internal structure and physical properties of…

We present a statistical study of the X-Ray emission toward 22 Herbig AeBe stars using the Chandra archive. We probe the origin of the X-Rays toward Herbig stars: are they intrinsic? This question is addressed by correlations between the…