Volume 27 (2017)

Contents

Spatial dependent systematic error correction and colour coefficients for the 2-m telescope of the Rozhen National Astronomical Observatory
Boyko M. Mihov, Lyuba S. Slavcheva-Mihova

Interstellar extinction toward Be/X-ray binary stars
Y. M. Nikolov, R. K. Zamanov, K. A. Stoyanov, J. Marti

The cataclysmic variable AE Aquarii: orbital variability in V band
R. Zamanov, G. Latev

The investigation of solar activity signals by analyzing of tree ring chronological scales
M.G. Nickiforov

Influence of celestial parameters on Mercury's perihelion shift
Michal Krizek

Mass of the compact object in the Be/gamma-ray binaries LSI+61^੦303 and MWC 148
R. Zamanov, J. Marti & M. T. Garcia-Hernandez

On the link between column density distribution and density scaling relation in star formation regions
Todor Veltchev, Sava Donkov and Orlin Stanchev

A deep decrease event in the brightness of the PMS star V350 Cep
Evgeni H. Semkov, Sunay I. Ibryamov, Stoyanka P. Peneva

Observations and light curve solutions of the eclipsing stars CSS J075205.6+381909 and NSVS 691550
D. Kjurkchieva, V. Popov, D. Vasileva, Y. Eneva, S. Ibryamov

Possible impact solutions of asteroid (99942) Apophis
Ireneusz Wlodarczyk

Rotation period determination for asteroid 9021 Fagus
G. Apostolovska, A. Kostov, Z. Donchev and E. Vchkova Bebekovska



Dissertation summaries:

Spectral and photometrical evidences of activity in the circumstellar envelopes of typical Be stars
Lubomir Iliev