A5077569570- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Multidisciplinary Science and Engineering Research
- Spacecraft Dynamics and Control
- Galaxies: Formation, Evolution, Phenomena
- Infrared Target Detection Methodologies
- Laser Design and Applications
- Atmospheric Ozone and Climate
- Optical Polarization and Ellipsometry
- Advanced Measurement and Detection Methods
- Coccidia and coccidiosis research
- Mathematics and Applications
Ege University
2007-2022
Netherlands Institute for Radio Astronomy
2022
Astronomy and Space
2012
The eclipsing binary T-Cyg1-12664 was observed both spectroscopically and photometrically. Radial velocities of components ground-based VRI light curves were obtained. Kepler's R-data radial for the system analysed simultaneously. Masses radii obtained as 0.680$\pm$0.021 M$_{\odot}$ 0.613$\pm$0.007 R$_{\odot}$for primary 0.341$\pm$0.012M$_{\odot}$ 0.897$\pm$0.012R$_{\odot}$ secondary star. distance to estimated 127$\pm$14 pc. wave-like distortion at out-of-eclipse is modeled with two...
The equivalent widths of C II $\lambda$ 4267 \AA line were measured for the mass-gaining primary stars 18 Algol-type binary systems. comparison EWs gainers with those single standard having same effective temperature and luminosity class clearly indicates that they are systematically smaller than stars. components classical Algols, located in main-sequence band HR diagram, appear to be poor We estimate $ [N_{C} /N_{tot}] relative Sun as -1.91 GT Cep, -1.88 AU Mon -1.41 TU Mon, indicating...
We present spectroscopic observations of the massive multiple system HD 167971, located in open cluster NGC 6604. The brighter component triple is overcontact eclipsing binary MY Ser with an orbital period 3.32 d. radial velocities and previously published UBV data obtained by Mayer et al. UBVRI light curves Davidge & Forbes are analysed for physical properties components. determine following absolute parameters: primary star Mp = 32.23 ± 0.54 M⊙, Rp 14.23 0.75 R⊙; secondary Ms 30.59 0.53 Rs...
Abstract We present new photometric two-colour observations of the double-lined close binary star VZ CVn. Combining two data sets obtained in 1971–72 and 2006, physical parameters both components were derived. After removing light variations due to eclipses proximity effects, a periodic variation more massive component with dominant period 1.068 76 d could be detected first set. In accordance its position on Hertzsprung–Russell diagram pulsation constant 0.62 d, primary CVn should an...
Abstract Taking into account the results obtained from models and analyses of BVRI light curves, we discuss nature V1464 Aql. The indicated that mass ratio system is q = 0.71 ± 0.02, while inclination ( i ) 38°.45 0°.22. primary component’s temperature as 7420 192 K, found secondary 6232 161 K. component was to be 1.74 0.05 M ⊙ , it 1.23 0.01 for secondary. radius 2.10 R 1.80 Revealing should not exhibit any eclipses, demonstrated main variation with large amplitude caused due ellipsoidal...
This paper is the second in planned series of investigations. We present new radial velocities and photometric observations V2080 Cyg V2365 Oph. New UBV data were analysed for systems' parameters. While consists two nearly equal F-type main-sequence stars, Oph has different components, namely an early A-type primary a G-type secondary star. ephemerides are calculated both systems. The masses component stars have been derived as 1.19 ± 0.02 1.16 M⊙ 1.97 1.06 0.01 effective temperatures...
Abstract Taking into account results obtained from light-curve analysis and out-of-eclipse analyses, we discuss the nature of GSC 02038-00293 also its magnetic activity behaviour.We light curves system during observing seasons 2007, 2008 2011. We secondary minimum clearly in I -band observations for first time. Analysing this curve, found physical parameters components. The indicates that possible mass ratio is 0.35. remaining V curves, extracting eclipses. modelled these using SPOTMODEL...
We present the first radial velocities and ground-based photometric observations of V1665 Aql AG Ari. These double-lined eclipsing binaries have eccentric orbits with eccentricities 0.24 0.09, respectively. New UBV data were analysed using a modified version Wilson–Devinney program for parameters systems. Good phase coverage relatively small scatter both in light radial-velocity curves meant that eccentricity argument periastron as well orbital stellar could be determined. Our solutions...
We present new radial velocities and UBV photometric observations of three eclipsing binaries, V799 Cas, BX Psc HD 172189, in order to increase the number close binaries with absolute parameters determined accurately. Standard wide-band indices for systems comparison stars were Using times mid-eclipses, ephemerides are calculated systems. Cas 172189 consist two well-detached components eccentric orbits. is a single-lined binary which consists late-A an early-K star. The effective...
We present UBVRI photometric measurements and spectroscopic observations of the double-lined eclipsing binary V821 Cas. The radial velocities were obtained by means cross-correlation technique. Simultaneous analyses multiband light curves RVs give absolute parameters for stars as: . An analysis O–C residuals yielded an apsidal motion in at a rate , corresponding to period U= 118 ± 19 yr. Subtracting relativistic contribution, we find that log k2obs=−2.590 which is agreement with value...
We present new radial velocities and photometric observations of three double-lined eclipsing binaries LL Aqr, MP Del NSV 20913. This paper is the third in planned series investigations. Standard wide-band indices for systems comparison stars were determined accurately. Using times mid-eclipses, ephemerides are calculated systems. These consist two well-detached components eccentric orbits. The effective temperatures hotter reddening have been estimated from Johnson UBV calibrations. New...
We present spectroscopic observations of the massive early type system V745\,Cas, embedded in a multiple star system. The brightest is eclipsing binary V745\,Cas with an orbital period 1.41 days. radial velocities both components and light curves obtained by $INTEGRAL$ $Hipparcos$ missions were analysed. are shown to be B0\,V primary mass M$_p$=18.31$\pm$0.51 M$_{\odot}$ radius R$_p$=6.94$\pm$0.07 R$_{\odot}$ B(1-2)\,V secondary M$_s$=10.47$\pm$0.28 R$_s$=5.35$\pm$0.05 R$_{\odot}$. Our...
The multicolour light curves and radial velocities for TYC 1031 1262 1 have been obtained analysed. includes a Cepheid with period of 4.15270 ± 0.00061 d. orbital the system is about 51.2857 0.0174 pulsation indicates that secular increasing at rate 2.46 0.54 min yr−1. observed B, V R magnitudes cleaned intrinsic variations primary star. remaining consist eclipses proximity effects, these analysed to obtain parameters. consists two evolved stars, F8 II + G6 II, masses M1 = 1.640 0.151 M⊙ M2...
We present spectroscopic observations of the double-lined Algol type eclipsing binary V1898Cyg. Analyses BV light curves and RVs led to determination fundamental stellar parameters V1898Cyg’s components. The absolute for stars are derived as: M1 = 6.054 ± 0.037 M⊙, M2 1.162 0.011 R1 3.526 0.009 R⊙, R2 2.640 0.010 Teff1 18000 600 K, Teff2 6200±200 K. residuals between observed computed times mid-eclipses were analysed a rate period change u P/P 6.68 ×10 −7 yr −1 was obtained; mass transfer...