Related papers: Variable stars in Palomar 13; an evaporating globu…

The giant HII region W31 hosts the populous star cluster W31-CL and others projected on or in the surroundings. The most intriguing object is the stellar cluster SGR1806-20, which appears to be related to a Luminous Blue Variable (LBV) - a…

We present a CCD $VI$ photometric study of the globular cluster M14. Particular attention is given to the variable stars. This allowed new classifications and cluster membership considerations. New variables are reported; 3 RRc, 18 SR and 1…

We report results of photometric monitoring of the NGC 2243 field in V and $I$ filters. Two W~UMa-type systems and three detached eclipsing binaries were discovered. Both contact systems are likely members of the cluster. One of detached…

Since the discovery of chemically peculiar stars in globular clusters in the last century, the study of multiple populations has become increasingly important, given that chemical inhomogeneity is found in almost all globular clusters.…

This work is part of an effort to detect secular variable objects in large scale surveys by analysing their path in color-magnitude diagrams. To this aim, we first present the variability morphologies in the V/V-I diagram of several types…

Stellar population and the interstellar gas-dust medium in the vicinity of the open star cluster vdB 130 are analysed using optical observations taken with the 6-m telescope of the SAO RAS and the 125-cm telescope of the SAI MSU along with…

We present B, V and I CCD light curves for 101 variable stars belonging to the globular cluster NGC2419, 60 of which are new discoveries, based on datasets obtained at the TNG, SUBARU and HST telescopes. The sample includes 75 RR Lyrae…

The luminosities of globular clusters are found to correlate with their half-light radii. The most luminous clusters have half-light radii r ~ 3 pc. Mean cluster luminosities are < Mv > = -6.64 +/- 0.26 for r < 2.0, < Mv > = -7.44 +/- 0.20…

The field of the globular cluster M12 (NGC 6218) was monitored between 1995 and 2009 in a search for variable stars. $BV$ light curves were obtained for 36 periodic or likely periodic variables. Thirty-four of these are new detections.…

This paper reports results from our long-term $BV(RI)_{c}$ photometric CCD observations of eight pre-main-sequence stars collected from June 2008 to October 2022. These stars are located in the young open cluster Trumpler 37, in the field…

We have monitored a 3 deg2 area toward Serpens Main in the Pan-STARRS1 r, i, and z bands from 2016 April to September. Light curves of more than 11,000 stars in each band were obtained, and 143 variables have been identified. Among those,…

We have undertaken a search for variable stars in the metal-rich globular cluster NGC 6441 using time-series BV photometry. The total number of variables found near NGC 6441 has been increased to ~104, with 48 new variables being found in…

Luminosities and tidal radii of globular clusters have been used to estimate the perigalactic distances P of well-observed Galactic globulars that do not have collapsed cores. It is found that the cluster metallicity [Fe/H] correlates…

The rapidly oscillating Ap (roAp) stars exhibit pulsational photometric and/or radial velocity variations on time scales of several minutes, which are essential to test current pulsation models as well as our assumptions of atmospheric…

Discerning the nature of open cluster candidates is essential for both individual and statistical analyses of cluster properties. Here we establish the nature of thirteen cluster candidates from the FSR cluster list using photometry from…

The field of the globular cluster NGC 3201 was monitored between 1998 and 2009 in a search for variable stars. $BV$ light curves were obtained for 152 periodic or likely periodic variables, 57 of which are new detections. Thirty-seven newly…

Two star-forming regions are studied: the young embedded open cluster vdB 130 and the protocluster neighbourhood observed in the head and tail of the cometary molecular cloud located in the wall of the expanding supershell surrounding the…

The first results are presented of a four-year program dedicated to the CCD observations of Cepheids in the nearby galaxy IC 1613. Since the program was carried out with a relatively small telescope, the Dutch 0.9 m at ESO-La Silla, the…

We have surveyed a 6.5' x 6.5' field centered on the globular cluster M56 (NGC 6779) in search for variable stars. We have detected seven variables, among which two objects are new identifications. One of the new variables is an RR Lyrae…

We present new discoveries of variable stars near the turnoff of the old open cluster NGC 7142. Contrary to previous studies, we detect eight contact or near contact eclipsing binaries (including three near the cluster turnoff), and most of…