Search

We present the photometric analysis of six short-period systems (EI Oct, V336 TrA, NX Boo, V356 Boo, PS Boo, and V2282 Cyg). This is the first photometric analysis of these systems except for V336 TrA. Observations were conducted for 27 nights at three observatories in the northern and southern hemispheres. We calculated a new ephemeris for each of the systems using our minimum times and additional literature. The Markov Chain Monte Carlo (MCMC) approach was used to determine the eclipse timing variation trends of the systems. We found a likely orbital growth for V336 TrA and PS Boo; four other systems show a linear trend in orbital period changes, which is most likely due to the accumulation of measurement errors in their linear ephemeris parameters. The light curve analysis was performed using the Physics of Eclipsing Binaries (PHOEBE) 2.3.59 version code with the MCMC approach. The absolute parameters of the systems were calculated by using the Gaia Early Data Release 3 (EDR3) parallax. The positions of the systems were also depicted on the Hertzsprung-Russell (H-R) and $logJ_0-logM$ diagrams. According to a sample, we were able to present relations for the mass-radius (M-R) relationships of contact binary systems. There is also a strong relationship between the mass ratio and the radius ratio in the W UMa systems for which we also provided a new relation. We compared the M-R updated relationships in this study with seven systems in other studies obtained using the spectroscopic method. In addition, we estimated some of the absolute parameters for 1734 EW systems, based on the new relationships., Comment: 11 Figures, 9 Tables, Accepted by the PASP Journal

\c{C}ukurova University Space Sciences and Solar Energy Research and Application Center (UZAYMER) was founded in 1991. In this work, we present current research in the fields of astronomy, astrophysics and solar energy and the astronomical infrastructure of the center. In addition, the astrometrological status of UZAYMER was investigated using long-term (20 years) data from the AstroGIS database and moderate-term (7 years) measurements taken from the meteorological station. Astronomical extinction coefficients, seeing conditions and light pollution measurements of UZAYMER were also obtained. Furthermore, the observation limits were determined for the UZAYMER 50 cm telescope (UT50) and the observation efficiency was evaluated. UZAYMER has reached a level that can support both national and international scientific collaborations with its improved technical infrastructure and increased human resources. With its annual number of clear nights, favorable weather conditions and dark sky values, UZAYMER ranks 972 in Group A of the Suitability Index for Astronomical Sites (SIAS) among the 2141 observatories., Comment: 14 pages, in Turkish

We present new BVR band photometric light curves of BO Aries obtained in 2020 and combined them with the Transiting Exoplanet Survey Satellite (TESS) light curves. We obtained times of minima based on Gaussian and Cauchy distributions and then applied the Monte Carlo Markov Chain (MCMC) method to measure the amount of uncertainty from our CCD photometry and TESS data. A new ephemeris of the binary system was computed employing 204 times of minimum. The light curves were analyzed using the Wilson-Devinney binary code combined with the Monte Carlo (MC) simulation. For this light curve solution, we considered a dark spot on the primary component. We conclude that this binary is an A-type system with a mass ratio of q=0.2074+-0.0001, an orbital inclination of i=82.18+-0.02 deg, and a fillout factor of f=75.7+-0.8%. Our results for the a(Rsun) and q parameters are consistent with the results of the Xu-Dong Zhang and Sheng-Bang Qian (2020) model. The absolute parameters of the two components were calculated and the distance estimate of the binary system was found to be 142+-9 pc., Comment: 7 Figures, 5 Tables, sent to New Astronomy journal