The revised version of the widely circulated preprint ``Neutrino Flavor Evolution Near A Supernova's Core'' by J. Pantaleone (astro-ph 9405008 on the Bulletin Board, Indiana University preprint IUHET-276) is wrong. It contains two errors which lead to incorrect conclusions regarding neutrino flavor transformation in the supernova environment. In this short note we discuss these errors.

Nodland and Ralston (astro-ph/9704196) claim evidence for a wavelength-independent cosmic birefringence. Although it has been shown (astro-ph/9704247, astro-ph/9704263) that the data analysed did not support this conclusion, the possibility of such an effect remains interesting. Here I present a much more accurate test using high-resolution radio images of distant radio galaxies and quasars. A preliminary application sets an upper limit about thirty times lower than the original claim.

This paper was accidentally submitted twice to astro-ph. This version has been withdrawn -- please see astro-ph/0601440 instead.

The main results of papers gr-qc/0307026 and gr-qc/0312068 are formulated. These results are opposite to conclusions of paper astro-ph/0305039 and comments gr-qc/0309036.

Using the ESO Telescope Bibliography database telbib, we have investigated the percentage of ESO data papers that were submitted to the arXiv/astro-ph e-print server and that are therefore free to read. Our study revealed an availability of up to 96% of telbib papers on arXiv over the years 2010 to 2017. We also compared the citation counts of arXiv vs. non-arXiv papers and found that on average, papers submitted to arXiv are cited 2.8 times more often than those not on arXiv. While simulations suggest that these findings are statistically significant, we cannot yet draw firm conclusions as to the main cause of these differences.

This paper has been withdrawn. Please see astro-ph/0502366.

This paper has been removed by arXiv admin because it was an erroneous duplicate of astro-ph/9411031.

Stanek et al. (astro-ph/0604113) have noted that the four low-redshift long-duration gamma-ray bursts (LSB) observed to date all occurred in faint, metal-poor galaxies. Given this selection, they argue that it is improbable that there has been a substantial population of Milky Way galaxy bursts sufficiently recently to affect life on Earth. This argument ignores the heterogeneity of stellar populations in the Milky Way, with evidence for continuing mergers with low-metallicity dwarf galaxies; observational analysis that points to LSBs being hosted by such galaxies undergoing interaction; and the existence of a likely recent GRB remnant in our galaxy.

Our understanding of space and time is probed to its depths by black holes. These objects, which appear as a natural consequence of general relativity, provide a powerful analytical tool able to examine macroscopic and microscopic properties of the universe. This introductory article presents in a pictorial way the basic concepts of black hole's theory, as well as a description of the astronomical sites where black holes are suspected to lie, namely binary X-ray sources and galactic nuclei.

We report on a new general relativistic computational model enhancing, in various respects, the capability of presently available tools for fitting spectra of X-ray sources. The new model is intended for spectral analysis of black-hole accretion discs. Our approach is flexible enough to allow easy modifications of intrinsic emissivity profiles. Axial symmetry is not assumed, although it can be imposed in order to reduce computational cost of data fitting. The main current application of our code is within the XSPEC data-fitting package, however, its applicability goes beyond that: the code can be compiled in a stand-alone mode, capable of examining time-variable spectral features and doing polarimetry of sources in the strong-gravity regime. Basic features of our approach are described in a separate paper (Dovciak, Karas & Yaqoob 2004). Here we illustrate some of its applications in more detail. We concentrate ourselves on various aspects of line emission and Compton reflection, including the current implementation of the lamp-post model as an example of a more complicated form of intrinsic emissivity.