728 datasets found

We present the results of our comprehensive study of the Galactic open star cluster NGC 6866. The positions of stars in the investigated region have been obtained with the...

Based on our UBVRI observations and X-ray data from the RXTE satellite we have investigated the variabilities of the Seyfert Galaxy 3C 120 over the period 1996-2008.

Results of multicolor observations of BL Lac in 1999-2001 are presented. We show that the spectral energy distribution of the variable component in the range from K to B had...

We present an analysis of CCD images (obtained at the Palomar 1.5m telescope) of more than 100 quasars; many of the objects have been or will be observed in the HST Key Project...

Using all available proper-motion and radial-velocity data, including new radial-velocity observations obtained for this investigation, probable members of the open cluster NGC...

We present photometric, astrometric, and kinematic studies of the old open star clusters NGC 1193 and NGC 1798. Both of the clusters are investigated by combining data sets from...

In this paper, using CCD observations of the galaxy NGC 5055 in the emission lines of Halpha and Hbeta (Rozas, 2007RMxAA, submitted), together with CCD observations in the...

We present results of a study that combines UBVI photometry, MK spectral classification and proper motions in the area of the, up to now unknown, open cluster Ruprecht 58 at the...

We present 33 transit minimum times of 20 transiting planets discovered by the CoRoT space mission, which have been obtained from ground-based observations since the mission's...

We have used the 2.3-meter Vainu Bappu Telescope to perform CCD imaging of X-ray-selected poor clusters of galaxies. Our sample consists of four X-ray luminous clusters in the...

We present the results of CCD UBV photometric and spectroscopic observations of the open cluster NGC 225. In order to determine the structural parameters of NGC 225, we...

We analysed the open clusters Czernik 2 and NGC 7654 using CCD UBV photometric and Gaia Early Data Release 3 (EDR3) photometric and astrometric data. Structural parameters of...

We present the results of CCD UBV observations of the open cluster NGC 6819. We calculated the stellar density profile in the cluster's field to determine the structural...

Results are presented from CCD BVRI-observations of 145 comparison stars in the neighborhoods of 14 Seyfert galaxies, 3 quasars, and 5 BL Lac objects with right ascensions of 12...

We use a complete, unbiased sample of 257 dwarf (10^8^M_{sun}<Mstar<10^9.5^M{sun}_) galaxies at z<0.08, in the COSMOS field, to study the morphological mix of the dwarf...

Hot Jupiters have been perceived as loners devoid of planetary companions in close orbital proximity. However, recent discoveries based on space-borne precise photometry have...

We present an extension of our previous research on the early-type galaxy population of the Antlia cluster (d~35Mpc), achieving a total coverage of ~2.6deg^2^ and performing...

We report the detection of 3714 variable stars towards the Galactic bulge, including 2521 previously uncatalogued variables, using time-series photometry extracted from data...

We have identified a population of passive spiral galaxies from photometry and integral field spectroscopy. We selected z<0.035 spiral galaxies that have WISE colours...

In this paper, we continue the release of high-level data products from the multiyear photometric survey collected at the 67/92cm Schmidt Telescope in Asiago. The primary goal...