4 papers
On the relationship between the ellipticity of Galactic globular clusters and their X-ray luminosity
Georgi P. Petrov, Svetoslav Botev, Antoniya Valcheva +1
We examine the dependence of the ellipticity of globular clusters in the Milky Way on their X-ray luminosity using two modern catalogs and combine them with optical and X-ray data…
Structural Parameters of the Globular Cluster M 15
M. V. Petkova, G. P. Petrov, N. M. Kacharov +1
We present a detailed analysis of the structural parameters of the globular cluster M 15 using g- and i-band photometric data from Pan-STARRS1 DR2. The central coordinates ($X_{\rm…
Quasars behind the disk of M31 galaxy
P. Nedialkov, B. F. Williams, V. D. Ivanov +6
We aim to increase the limited number of quasars behind M31, necessary for probing the chemical content of the gas and for proper motion reference, with reliable and homogeneous re…
Investigation of the Nature of the B[e] Star CI Cam in the Optical Range
E. A. Barsukova, A. N. Burenkov, V. P. Goranskij +10
We report the results of 24 years of photometric and spectroscopic monitoring of CI Cam since its outburst in 1998. In the early years of our research, we identified a system compo…