相关论文: Separation of dwarf and giant stars with ROTSE-III…
Evolutionary pathways of binary systems are vastly different from single stellar evolution, and thus, there is a need to quantify their frequency and diversity. Open clusters are the best test-bed to unveil the secrets of binary populations…
New photoelectric seven-color observations in the Vilnius system are presented for 65 stars in the region of the open cluster NGC 752. Based on individual stars with accurate photometric classifications, we determine the apparent distance…
Open star clusters older than ~ 1 Gyr are rare in the inner Galactic disc. Still, they are objects that hold crucial information for probing the chemical evolution of these regions of the Milky Way. We aim at increasing the number of old…
The chemical composition of stars in open clusters provides the best information on the chemical evolution of stars via comparison of the main sequence stars with the evolved giants. This is a case study of the abundances in the dwarfs and…
The nearby open cluster NGC 752 presents a rare opportunity to study stellar properties at ages >1 Gyr. However, constructing a membership catalog for it is challenging; most surveys have been limited to identifying its giants and dwarf…
Photometry in the B and V bands is presented for the southern stellar groups NGC 1901 and NGC 1252. NGC 1901 is often described as an open cluster while NGC 1252 consists of a concentration of about 20 stars centered approx 20' north of the…
We present detailed chemical compositions of 10 red giant star members of the Galactic (open) cluster NGC 752, derived from high-resolution (R $\approx$ 60,000), high signal-to-noise ($S/N$ $\geq$ 140) spectra. We confirmed cluster…
We report on CCD optical (B and V passbands) and near IR (J and K bands) observations in the region of the old open cluster NGC 2141. By combining the two sets of photometry (500 stars in common) we derive new estimates of the cluster…
We present and discuss new photometric data obtained with an IR camera in the J and K pass-bands for the intermediate age open clusters IC 166 (936 stars in total) and NGC 7789 (1030 stars in total). Ic 166 is a poorly studied open cluster…
We continue our survey for magnetic chemically peculiar (CP2) stars in galactic open clusters to shed more light on their origin and evolution. To study the group of CP2 stars, it is essential to find these objects in different galactic…
We present and discuss radial velocity and the very first metallicity measurements for nine evolved stars in the poorly known old open cluster NGC 7762. We isolated eight radial velocity cluster members and one interloper. Radial velocities…
In a sample of six young open clusters we investigated 1753 objects using the narrow band, three filter Delta a photometric system resulting in the detection of eleven bona-fide magnetic chemically peculiar (CP) stars and five Be or…
We investigated the age-metallicity relation using a sample of 5691 F and G type dwarfs from RAVE DR3 by applying several constraints: i) We selected stars with surface gravities log g < 3.8 and effective temperatures in the…
The blue compact dwarf galaxy NGC 5253 hosts a very young starburst containing twin nuclear star clusters, separated by a projected distance of 5 pc. One cluster (#5) coincides with the peak of the H-alpha emission and the other (#11) with…
We present reddening, photometric metallicity, age and distance estimates for the Frolov 1 and NGC 7510 open clusters based on CCD UBV photometric and Gaia data. Photometric observations were collected using the 1-m telescope of the…
Asteroseismic modelling of isolated star presents significant challenges due to the difficulty in accurately determining stellar parameters, particularly the stellar age. These challenges can be overcomed by observing stars in open…
The results of medium-band photometry of 1037 stars in the area of old open cluster NGC 7142 down to V = 20.1 mag in the Vilnius seven-colour system are presented. Photometric results are used to classify in spectral and luminosity classes…
We present CCD BV and JHK$_{s}$ 2MASS photometric data for the open cluster NGC 1513. We observed 609 stars in the direction of the cluster up to a limiting magnitude of $V\sim19$ mag. The star count method shows that the centre of the…
Star clusters are ideal platforms for categorising X-ray emitting stars and to study X-ray emission as a function of stellar age and activity. We present a comprehensive study of an open star cluster, NGC2527, by combining data from…
We present griz observations for the clusters M92, M13 and NGC 6791 and gr photometry for M71, Be 29 and NGC 7789. In addition we present new membership identifications for all these clusters, which have been observed spectroscopically as…