Related papers: The contact binary V344 Lacertae: is it a triple s…
Multi-wavelength VLA observations of two extended radio galaxies, 0235-197 and 1203+043 are presented. There is some evidence from earlier studies that these two sources exhibit low frequency (<1 GHz) variability. This work shows that both…
In this paper, CCD photometric light curves for the short-period eclipsing binary 1SWASP J140533.33+114639.1 (hereafter J1405) in the $BVR$ bands are presented and analyzed using the 2013 version of the Wilson-Devinney (W-D) code. It is…
The cut-off mass ratio is under debate for contact binaries. In this paper, we present the investigation of two contact binaries with mass ratios close to the low mass ratio limit. It is found that the mass ratios of VSX J082700.8+462850…
We report spectroscopic observations of the 2.63 day, detached, F-type main-sequence eclipsing binary V2154 Cyg. We use our observations together with existing $uvby$ photometric measurements to derive accurate absolute masses and radii for…
OO Peg is a detached eclipsing binary system containing two late-A-type stars in a circular orbit with a period of 2.985 d. Using published spectroscopic results and a light curve from the Transiting Exoplanet Survey Satellite (TESS) we…
The LHS 6343 system consists of a resolved M-dwarf binary with an evolved, negligibly irradiated brown dwarf, LHS 6343 C, orbiting the primary star. Such brown dwarf eclipsing binaries present rare and unique opportunities to calibrate…
The structure of the tetraquark candidate $Z_{c}(3900)$, which was experimentally reported in $e^+ e^-$ collisions, is studied by the s-wave meson-meson coupled-channel scattering on the lattice. The s-wave interactions among the $\pi…
In this paper, we estimated the physical and geometrical characteristics of the visually close binary stellar system Hip 45571, using Al-Wardat's method for analyzing binary and multiple stellar systems. We estimated the physical properties…
Photometric observations for the totally eclipsing binary system TYC 4002-2628-1, were obtained between November 2020 and November 2021. To determine the stellar atmospheric parameters, a spectral image was taken with the 2.16 m telescope…
We report the discovery of the closest known black hole candidate as a binary companion to V723 Mon. V723 Mon is a nearby ($d\sim460\,\rm pc$), bright ($V\simeq8.3$~mag), evolved ($T_{\rm eff, giant}\simeq4440$~K, and $L_{\rm…
We have found a system listed in the Kepler Binary Catalog (3.273 day period; Prsa et al. 2010) that we have determined is comprised of a low-mass, thermally-bloated, hot white dwarf orbiting an A star of about 2.3 solar masses. In this…
We describe here results of a photometric time-sequence survey of the globular cluster M3 (NGC 5272), in a search for contact and detached eclipsing binary stars. We have discovered only one likely eclipsing binary and one SX Phe type star…
This paper aims to investigate the hypothesis that the embedded luminous star AFGL2591-VLA3 (2.3E5Lsun at 3.33kpc) is forming according to a scaled-up version of a low-mass star formation scenario. We present multi-configuration VLA 3.6cm…
A photometric solution of an A-type W UMa binary, GSC 0763-0572 is examined with a revised orbital period. The overcontact degree is found to be $f$ = 40.66%, with a low mass ratio of $q$ = 0.2554. The result demonstrates an unambiguous…
We present new long-term CCD photometry for EP And acquired during the period 2007 to 2012. The light curves display total eclipses at primary minima and season-to-season light variability. Our synthesis for all available light curves…
LS I +61 303 is a puzzling object detected from radio up to high-energy gamma-rays. Variability has recently been observed in its high-energy emission. The object is a binary system, with a compact object and a Be star as primary. The…
This study continues our in-depth investigation of total-eclipse W Ursae Majoris-type contact binaries by analyzing eight new systems, complementing our previous work. Multiband $BVR_cI_c$ photometric data were acquired through ground-based…
V570 Per is a binary star system containing two F-type stars in a 1.90 d period circular orbit. It shows shallow partial eclipses that were discovered from its Hipparcos light curve. We present an analysis of this system based on two…
The star NGC2004#115 in the LMC, originally classified as an (SB1) Be spectroscopic binary, bears some morphological resemblance to the Galactic systems LB-1 and HR 6819, both of which are proposed as either Be+black hole (BH) or…
Here we present the observations and the first light curve analysis of the short-period variable star NSVS 2983201. Using the light curve numerical modeling we find the best fitting model to be of shallow (ff=10%) contact binary…