Related papers: Variable stars in young open star cluster NGC 7380
We report an analysis of new $V$ and $I$ CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves, the mean values of [Fe/H] and the distance of the cluster were estimated,…
We present the analysis of 11 nights of V and I time-series observations of the globular cluster NGC 1904 (M 79). Using this we searched for variable stars in this cluster and attempted to refine the periods of known variables, making use…
Three fields located close to the center of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 32 periodic variables. This sample includes 10 SX Phe stars, 19 eclipsing binaries,…
Two sets of archive time series observations of an old open cluster NGC 6791 were re-analysed using an image subtraction technique. We report identification of four new variables. Proper motion data are available for three of them and…
We report on observation and determination of rotational periods of ten weak-line T Tauri stars in the Cepheus-Cassiopeia star-forming region. Observations were carried out with the Cassegrain-Teleskop-Kamera (CTK) at University Observatory…
We present a variability study of 4646 massive stars in the Small Magellanic Cloud (SMC) with known spectral types from the catalog of Bonanos et al. (2010) using the light curves from the OGLE-III database. The goal is to exploit the time…
We present the results of a search for variable stars in a 26x39 arcmin^2 field around globular cluster M79 (NGC1904). The search was made by means of an extended version of image subtraction, which allows to analyze in a uniform manner CCD…
NGC 6910 is the northern hemisphere open cluster known to be rich in $\beta$ Cephei-type stars. Using four-season photometry obtained in Bia\l k\'ow (Poland) and Xinglong (China) observatories, we performed variability survey of NGC 6910.…
We present a CCD $VI$ time-series analysis of the globular cluster NGC 6139 and its variable star population. Using the astrometric data available in $Gaia$-DR3 we performed a membership analysis that enabled the construction of a clean…
NGC 6231 is a young cluster (age ~2-7 Myr) dominating the Sco OB1 association (distance ~1.59 kpc) with ~100 O and B stars and a large pre-main-sequence stellar population. We combine a reanalysis of archival Chandra X-ray data with…
We present the results of a search for variable stars in the central part of the globular cluster NGC 6752. The monitored sample included 160 BHB and 107 EHB stars, respectively. A total of 17 variables were detected of which 14 are new…
Three fields covering the central part of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 22 periodic variables: 9 SX~Phe stars, 7 contact binaries, 5 detached or semi-detached…
We have performed a photometric V, R, I CCD time-series analysis with a baseline of ~8 years of the outer-halo globular cluster NGC 7492 with the aim of searching for new variables and using these (and the previously known variables) to…
We monitored the light variations of 22 weak-line T Tauri stars (WTTS) discovered among the X-ray sources in the field of the Taurus-Auriga cloud. The photometric variability of 12 out of these WTTS samples is confirmed. They are all proved…
New CCD photometry of NGC 6366 has lead to the discovery of some variable stars. Two possible Anomalous Cepheids (or Pop II Cepheids), three long period variables, one SX Phe and one eclipsing binary have been found. Also a list of 10…
We present a variable star catalog of an extensive ground-based wide-field variability survey in the globular cluster omega Centauri. Using the ANU 40-inch (1m) telescope at Siding Spring Observatory, the cluster was observed with a 52'x52'…
We characterize the stellar population of the poorly explored young stellar cluster NGC 3293 at the northwestern periphery of the Carina Nebula Complex, in order to evaluate the cluster age and the mass function, and to test claims of an…
We present a unique, homogeneous database of photometric measurements for Classical T Tauri stars extending up to 20 years. The database contains more than 21,000 UBVR observations of 72 CTTs. All the data were collected within the…
Time-domain studies of pre-main sequence stars have long been used to investigate star properties during their early evolutionary phases and to trace the evolution of circumstellar environments. Historically these studies have been confined…
CCD observations for 10 (6 previously known and 4 newly discovered) of the 11 RR Lyrae variables in NGC 5897 have been analysed. The period-luminosity and period-amplitude plots indicate that the population of RR Lyrae variables in NGC 5897…