Publications
Section: PZ: main journal
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In June and September 2004, 673 photoelectric BVR_c brightness measurements were made for 24 Cepheids using the 60-cm reflector of Mt. Maidanak Observatory. $V$ light curves and $B-V$ and $V-R_c$ colour curves are presented.
We present 4660 magnitude measurements in the B, V, and I_c filters acquired for 164 RR Lyrae stars.
CCD BVRI photometry is presented for the type Ic-BL Supernovae 2016coi and 2018ebt. The shape of the light curves for both objects is typical for this class of SNe. A change of brightness decline rate at about 100 days after maximum light is observed for SN 2016coi. The light curves of SN 2018ebt are best matched by those of SN Ic-BL 2002ap. For SN 2018ebt, we derived the dates and magnitudes of maximum light, rates of decline at late stages of evolution, and presented evidence for extinction in the host galaxy being negligible.
We present a photometric study of two new double-mode Cepheids, pulsating in the first and second overtones modes: V470 Cas and GSC 02901-00089. For the search for double-mode variability, we used all available observations from the ROTSE-I/NSVS and 1SWASP online public archives. Our multicolour CCD observations in the B, V and R bands in Johnson's system and ASAS-SN data in the V filter (that became available later) confirm the double-mode periodicity of these variables. We study period variations of the two stars; variations of the first-overtone periods were reliably detected.
We present the second part of a new Name-List of variable stars containing information on 1353 variable stars recently designated in the system of the General Catalogue of Variable Stars. With the exception of Novae and other unusual variables named upon request from the IAU CBAT or by our initiative, these stars are in the range of J2000.0 right ascensions from 18 hours 00 minutes to 20 hours 00 minutes.
A total of 9128 B-, V-, and I_c-band photometric measurements were acquired for 64 classical Cepheids in 1982 - 2014. For these stars, 1384 times of maximum light are determined and O-C diagrams constructed based on available photoelectric and CCD observations. The data are used to compute the current ephemerides and the normalized Fourier coefficients (cosine expansion), whose analysis confirmed that all the 64~variables were correctly classified as classical Cepheids.
We present 2902 magnitude measurements in the B, V, and I_c} filters acquired in 1999 - 2004 for 16 double-mode classical Cepheids.
We obtained a spectrum and UBVRI photometry of the star associated with the X-ray source 1RXS J051439.2-021615 that experienced a rapid optical flare on 25 January 2018 (ATel No. 11250). We classified the spectrum as K2V - K5V. The Halpha line was filled with emission. We explain this event as a flare in an active region on the surface of a late-type main sequence star.
GCVS names are announced for 14 galactic Novae discovered in 2018.
We present our variability study of the new cataclysmic variable star, 2MASS 23212116+3807563. The variable is a U Geminorum type star. An analysis of available electronic archives data (CSS, 1SWASP and ASAS-SN) does not detect periodicity. The variable has a close companion, photometric data in the electronic archives present combined light of the two stars. We acquired the star's new CCD photometry in Johnson's B, V, and R bands. Our observation confirm variability of 2MASS 23212116+3807563 with a large amplitude of light variations (more than 3m). |
