Title Page

Contents

Extragalactic astronomy

Dynamics, mass and physical characteristics of the spiral galaxies NGC 1084, 6503, 7339 and 7537
G. T. Petrov, G. A. Kyazumov, B. Zh. Kovachev, V. A. Mineva

On the gradients of surface brightness of the Andromeda Galaxy
Tz. Georgiev, B. Bilkina, G. Ivanov (in Russian, Summary in English; zoomed versions of Figs. 3, 6a, 6b are enclosed)

Large-scale surface photometry of M 31 Galaxy
Ts. Georgiev (in Russian, Summary in English)

Foreground contamination of the spiral arm S3 in the M33 galaxy
P. Kunchev

Stellar clusters and associations

Investigation of the structure of the open cluster NGC 6939
M. Popova, A. Antov (in Russian, Summary in English)

Theoretical C-M diagrams of open clusters
M. Popova, Z. Kraicheva (in Russian, Summary in English)

New peculiar stars identified on objective-prism plates
Tz. Radoslavova (in Russian, Summary in English)

On the clumps of red giants on the C-M diagrams of the open clusters
M. Popova, O. Dluznevskaya, A. Antov, A. Piskunov (in Russian, Summary in English)

Possible mass loss from red giants in old open clusters
A. Antov, M. Popova

Variables of the U Geminorum type – possible members of open clusters
M. Popova, Z. Kraicheva (in Russian, Summary in English)

Photometric study of the core of the globular cluster M 15
N. Spasova (zoomed version of Fig. 4 is enclosed)

Spectral classification of stars in the direction of the OB-associations Cygnus OB4, Cepheus-Lacerta OB1 and Cassiopeia OB9
Tz. Radoslavova

Spectral absolute magnitudes of 312 stars of spectral classes B5-A3 in the region of the association Cygnus OB4
Tz. Radoslavova (in Russian, Summary in English)

Stars

The spectrum of θ Virginis
V. Dobrichev, D. Raikova

The LV Vulpeculae spectrum before the light maximum
D. Raikova

The Sun

The solar element abundances and the scale of Kurucz and Peytremann’s oscillator strengths
D. Raikova, V. Dobrichev

Formation of surge prominences in the solar atmosphere. II. Two-dimensional hydromagnetic numeric experiments
V. Dermendjiev, G. Buyukliev, K. Stavrev

Magnetohydrodynamic model of the X-ray elementary solar flare bursts
V. N. Dermendjiev

Celestial mechanics. Planets

On the application of universal Battin functions for determination of comet orbits
B. Nikolov, St. Spassov (in Russian, Summary in English)

The influence of several internal mass motions upon cosmic bodies’ rotation
V. Mileva (in Russian, Summary in English)