740 datasets found

The results of classical CCD observations for 371 double or multiple stars (450 pairs) obtained at both, Serbian Astronomical Station on the mountain of Vidojevica (ASV) and...

We report the discovery of a new ultra-short-period planet and summarize the properties of all such planets for which the mass and radius have been measured. The new planet,...

Results of CCD observations of 154 double or multiple stars, made with the 2 m telescope of the Bulgarian National Astronomical Observatory at Rozhen over five nights in 2015,...

Precision uvbyCaH{beta} photometry of the metal-deficient, old open cluster NGC2506 is presented. The survey covers an area of 20'*20' and extends to V~18 for b-y and H{beta}...

Using the 2m telescope of the Bulgarian National Astronomical Observatory at Rozhen, observations of 271 double or multiple stars were carried out during seven nights in 2013...

We present multi-color photometric observations for two neglected near-contact binaries, IZ Mon (P=0.77980^d^) and AR Dra (P=0.67584^d^). By the aid of the updated W-D analysis...

Precision uvbyCaH{beta} photometry of the nearby old open cluster, NGC752, is presented. The mosaic of CCD fields covers an area ~42' on a side with internal precision at the...

In this paper, new CCD photometric observations of V508 Oph obtained in 2009 and 2010 at the Xinglong Observatory are presented. From the new observations, six new times of...

IM Per is a detached A7 eccentric eclipsing binary star. We have obtained extensive measurements of the light curve (28225 differential magnitude observations) and radial...

New CCD photometry is presented for the hot overcontact binary DK Cyg together with reasonable explanations for the light and period variations. Historical light and velocity...

We present a detailed investigation of the low-amplitude contact binary HI Dra based on the new VR_c_I_c_ CCD photometric light curves (LCs) combined with published radial...

Using the 2m telescope of the Bulgarian National Astronomical Observatory at Rozhen, observations of 246 double or multiple stars were carried out during six nights in 2012....

We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau, and V2612 Oph, and determine their orbital and physical parameters...

New multiband CCD photometry is presented for V407 Peg; the R_C_ light curves are the first ever compiled. Our light curves, displaying a flat bottom at secondary minimum and an...

We use CCD and photoelectric photometry with Stromgren filters along with medium resolution spectra to investigate NGC 6520, an open cluster very nearly in the direction of the...

NGC 188 is a good laboratory for studying the formation and evolution of W UMa type contact binaries due to its rich populations of them. We present a detailed photometric study...

AP And is a well-detached F5 eclipsing binary star for which only a very limited amount of information was available before this publication. We have obtained very extensive...

New extensive photometry for two triple binary stars, DI Peg and AF Gem, was performed from 2012 October to 2013 January, with two small telescopes at Xinglong station (XLs) of...

We have developed a maximum-likelihood procedure to fit theoretical isochrones to the observed cluster color-magnitude diagrams of NGC6866, an open cluster in the Kepler...

We present proper motions and astrometric membership analysis for 15750 stars around the intermediate-age open cluster NGC 6819. The accuracy of relative proper motions for...