20 citations · 68 across the 9 of their papers we have counts for
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Spectral observations of X Persei: Connection between H-alpha and X-ray emission
R. Zamanov, K. A. Stoyanov, U. Wolter +2
We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 1999 - 2018. Using new and published data, we found that during "disc-rise" the expans…
The W UMa binaries USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac: light curve solutions and global parameters based on the GAIA distances
Diana P. Kjurkchieva, Velimir A. Popov, Yordanka Eneva +1
We present photometric observations in Sloan filters g', i' of the eclipsing W UMa stars USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram o…
NSVS 2569022: a peculiar binary among the W UMa stars with extremely small mass ratios
Diana P. Kjurkchieva, Velimir A. Popov, Nikola I. Petrov
Photometric observations of the W UMa binary NSVS 2569022 are presented. The light curve solution reveals that both components are of F spectral type (temperatures ==6100…