Related papers: The Distance to the LMC via the Eclipsing Binary H…
Photometric and spectroscopic observations of the unstudied 12th-magnitude eclipsing binary GSC 04778-00152 are presented. We report the discovery of a visual companion about 1 mag fainter and 2 arcsec away from the binary. By subtracting…
High-resolution Hubble Space Telescope (\textit{HST}) optical observations have been used to perform the deepest photometric study of the poorly studied Galactic globular cluster NGC 6284. The deep colour-magnitude diagram (CMD) that we…
Aims: As part of our observational projects at the La Silla Danish 1.54-meter telescope, we aim to measure the precise times of minimum light for eccentric eclipsing binaries in the Large Magellanic Cloud, needed for accurate determination…
We found that the known spectroscopic binary and variable BU~CMi = HD65241 ($V$=6.4-6.7 mag, Sp~=~A0~V) is a quadruple doubly eclipsing 2+2 system. Both eclipsing binaries are detached systems moving in an eccentric orbits: pair "A" with…
We present the results of CCD UBVRI observations of the open cluster NGC 6811 obtained on 18th July 2012 with the 1m telescope at the T\"UB\.ITAK National Observatory (TUG). Using these photometric results, we determine the structural and…
Detached eclipsing double line spectroscopic binaries are accurate distance indicators. They can be used for the direct determination of distances to globular clusters in which such systems can be identified. The results of major…
We have determined column densities of H I and/or H_2 for sight lines in the Magellanic Clouds from archival HST and FUSE spectra of H I Lyman-alpha and H_2 Lyman-band absorption. Together with some similar data from the literature, we now…
We study the spectral properties in the range 3600 \AA - 6800 \AA of the nuclear region of galaxies behind the Magellanic Clouds. The radial velocities clarified the nature of the objects as background galaxies or extended objects belonging…
First photometric study for the newly discovered systems USNO-B1.0 1091-0130715 and GSC-03449-0680 were applied by means of recent windows interface version of the Wilson and Devinney code based on model atmospheres by Kurucz (1993). The…
We present VI photometry of the metal-poor inner halo globular clusters NGC6293 and NGC6541 using the planetary camera of the WFPC2 on board HST. Our color-magnitude diagrams of the clusters show well-defined BHB populations, consistent…
Published B and V fluxes from nearby Type Ia supernovae are fitted to light-curve templates with 4-6 adjustable parameters. Separately, B magnitudes from the same sample are fitted to a linear dependence on B-V color within a post-maximum…
We present a new sample of 4634 eclipsing binary stars in the Large Magellanic Cloud (LMC), expanding on a previous sample of 611 objects and a new sample of 1509 eclipsing binary stars in the Small Magellanic Cloud (SMC), that were…
We present a detailed investigation of the Large Magellanic Cloud (LMC) disk using classical Cepheids. Our analysis is based on optical (I,V; OGLE-IV), near-infrared (NIR: J,H,Ks) and mid-infrared (MIR: w1; WISE) mean magnitudes. By…
We present the catalog of 1459 eclipsing binary stars detected in the central 2.4 square degree area of the Small Magellanic Cloud during the OGLE-II microlensing search. The sample includes objects brighter than I=20 mag with periods…
We investigate the reddening and Main Sequence fitted distances to eleven young, Galactic open clusters that contain Cepheids. Each cluster contains or is associated with at least one Cepheid variable star. Reddening to the clusters is…
We present deep CCD BVI photometry of the distant, old open cluster Berkeley 22, covering from the red giants branch (RGB) to about 6 magnitudes below the main sequence (MS) turn-off. Using the synthetic Colour - Magnitude Diagram method…
Thanks to the outstanding capabilites of the HST, our current knowledge about the M31 globular clusters (GCs) is similar to our knowledge of the Milky Way GCs in the 1960s-1970s, which set the basis for studying the halo and galaxy…
Context. Recently, the high-energy (HE, 0.1-100 GeV) $\gamma$-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic…
We report the first observations of far-ultraviolet (FUV: 1000 -- 1150 \AA) diffuse radiation from the Small Magellanic Cloud (SMC) using observations from the {\em Far Ultraviolet Spectroscopic Explorer (FUSE)}. The strength of FUV diffuse…
New CCD observations for thirteen eccentric eclipsing binaries from the Large Magellanic Cloud were carried out using the Danish 1.54-meter telescope located at the La Silla Observatory in Chile. These systems were observed for their times…