... Printed in the U.S.A. ON THE CONSTANCY OF THE PHOTON INDEX OF X-RAY SPECTRA OF 4U 1728-34 THROUGH ALL SPECTRAL STATES Elena Seifina1 and Lev Titarchuk2 1 2 ,3 ,4 Sternberg Astronomical Institute, Moscow State University, Universitetsky Prospect ... We find that the X-ray broadband energy spectra of 4U 1728-34 during all spectral states can be modeled by a combination of a thermal (blackbody-like) component, a Comptonized component (which we herein denote as COMPTB), and a Gaussian component. ...

Comment on J0513-2159 . Our image shows an extension to about 5 mas SE from the brightest feature. The EVN 8 GHz image by Dallacasa et al. (1998), with about five times larger resolution, shows an extension from the brightest feature roughly opposite to our direction. As noted by Dallacasa et al. (1998), the structure detected has a highly inverted spectrum, which, together with the reported variability in the source, could explain the structural disagreement. ...

... Multiexposition 34 images Sun 1/1000 sec f/22 and 1 image background. ... It shows position of the Sun on the sky in the same time of a day during one year. Analemma - a trace of the annual movement of the Sun on the sky - is well known among experts of sun-dials and old Earth's globes as a diagram of change of seasons and an equation of time. ... Previously, the position of the Sun on the sky was calculated with computer as well as optimal moments of time for taking each of the exposures. ...

... For reliable estimation of the accuracy of asteroid CCD observations we usually consider from ten or more various NUMBERED MINOR PLANETS (NMPs) observed during several nigths per month (more then 50 positions). ... They can be considered as an indicator of accuracy of the CCD positional observations with given MPC code. ... For any NUMBERED minor planet the (O-C) values must be zero if the errors of observations and the errors of its theory are absent. ...