48 citations · 279 across the 22 of their papers we have counts for
22 papers
Precise physical and kinematical parameters of massive eclipsing binaries in the Small Magellanic Cloud
M. Kaya, Ö. Çakırlı, B. Hoyman +3
The formation of massive stars serves an important field of study, requiring research into whether these stars need to form together within clusters of low-mass stars or if they ar…
A Comprehensive Study of Czernik 41 and NGC 1342 Using CCD UBV and Gaia DR3 Data
B. Tanik Ozturk, S. Bilir, T. Yontan +5
In this study, the structural, astrophysical, kinematic, and Galactic orbital parameters of the open clusters Czernik 41 and NGC 1342, as well as their dynamical evolution, are inv…
Transformation relations for UBV photometric system of 1m telescope at the TÜBİTAK National Observatory
T. Ak, R. Canbay, T. Yontan
UBV CCD observations of standard stars selected from Landolt (2009, 2013) were performed using the 1-meter telescope (T100) of the TÜBİTAK National Observatory equipped with a back…
Photometric and kinematic studies of open clusters Ruprecht 1 and Ruprecht 171
Hikmet Çakmak, Talar Yontan, Selçk Bilir +5
This study outlines a detailed investigation using CCD {\it UBV} and {\it Gaia} DR3 data sets of the two open clusters Ruprecht 1 (Rup-1) and Ruprecht 171 (Rup-171). Fundamental as…
CCD UBV and Gaia DR3 Analyses of Open Clusters King 6 and NGC 1605
S. Gokmen, Z. Eker, T. Yontan +5
A detailed analysis of ground-based CCD UBV photometry and space-based Gaia Data Release 3 (DR3) data for the open clusters King 6 and NGC 1605 was performed. Using the pyUPMASK al…
A study of the NGC 1193 and NGC 1798 open clusters using CCD UBV photometric and Gaia EDR3 data
T. Yontan, H. Cakmak, S. Bilir +8
We present photometric, astrometric, and kinematic studies of the old open star clusters NGC 1193 and NGC 1798. Both of the clusters are investigated by combining data sets from Ga…
A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data
B. Akbulut, S. Ak, T. Yontan +5
We analysed the open clusters Czernik 2 and NGC 7654 using CCD UBV photometric and Gaia Early Data Release 3 (EDR3) photometric and astrometric data. Structural parameters of the t…
A Study of Open Clusters Frolov 1 and NGC 7510 using CCD UBV Photometry and Gaia DR2 Astrometry
T. Yontan, S. Bilir, T. Ak +6
We present reddening, photometric metallicity, age and distance estimates for the Frolov 1 and NGC 7510 open clusters based on CCD UBV photometric and Gaia data. Photometric observ…
Bridging the Ultraviolet and Optical Regions: Transformation Equations between {\it GALEX} and {\it UBV} Photometric Systems
S. Bilir, N. Alan, S. Tuncel Guctekin +6
We derive transformation equations between GALEX and UBV colours by using the reliable data of 556 stars. We present two sets of equations; as a function of (only) luminosity class…
Vilnius Photometry and Gaia Astrometry of Melotte 105
Timothy Banks, Talar Yontan, Selcuk Bilir +1
Archival Vilnius CCD photometric observations are presented for the heavily reddened star cluster Melotte 105, resulting in colour-magnitude diagrams and spectral class estimates.…
Metallicity and absolute magnitude calibrations for F-G type main-sequence stars in the Gaia era
M. Celebi, S. Bilir, S. Ak +3
In this study, photometric metallicity and absolute magnitude calibrations were derived using F-G spectral type main-sequence stars in the Solar neighbourhood with precise spectros…
CCD UBV photometric and Gaia astrometric study of eight open clusters- ASCC 115, Collinder 421, NGC 6793, NGC 7031, NGC 7039, NGC 7086, Roslund 1 and Stock 21
T. Yontan, S. Bilir, Z. F. Bostanci +8
In this study, we carried out CCD UBV photometry of eight open clusters, ASCC 115, Collinder 421, NGC 6793, NGC 7031, NGC 7039, NGC 7086, Roslund 1, Stock 21, and determined their…
CCD UBV photometric study of five open clusters - Dolidze 36, NGC 6728, NGC 6800, NGC 7209 and Platais 1
Z. F. Bostanci, T. Yontan, S. Bilir +9
In this study, we present CCD UBV photometry of poorly studied open star clusters, Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1, located in the first and second Galactic…
CCD UBV photometry of the open cluster NGC 6819
T. Ak, Z. F. Bostanci, T. Yontan +5
We present the results of CCD UBV observations of the open cluster NGC 6819. We calculated the stellar density profile in the cluster's field to determine the structural parameters…
A New Ranking Scheme for the Institutional Scientific Performance
S. Bilir, E. Gogus, O. Onal Tas +1
We propose a new performance indicator to evaluate the productivity of research institutions by their disseminated scientific papers. The new quality measure includes two principle…
A comprehensive study of the open cluster NGC 6866
Z. F. Bostanci, T. Ak, T. Yontan +15
We present CCD photometry of the field of the open cluster NGC 6866. Structural parameters of the cluster are determined utilizing the stellar density profile of the stars…
CCD UBVRI photometry of NGC 6811
T. Yontan, S. Bilir, Z. F. Bostancı +6
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 TÜBİTAK National Observatory (TUG). Using thes…
Colour Transformations between BVRc and g'r'i' Photometric Systems for Giant Stars
S. Ak, T. Ak, S. Karaali +9
The transformation equations from to magnitudes and vice versa for the giants were established from a sample of 80 stars collected from Soubiran et al. (2010) with…
The early-type near-contact binary system V337 Aql revisited
M. Tuysuz, F. Soydugan, S. Bilir +3
The close binary V337 Aql consists of two early B-type components with an orbital period of 2.7339 d. New multi-band photometric observations of the system together with published…
A New Absolute Magnitude Calibration for Red Clump Stars
S. Bilir, T. Ak, S. Ak +2
We present an M_V absolute magnitude calibration including the B-V colour and [Fe/H] metallicity for the red clump stars in the globular and open clusters with a wide range of meta…
Research Performance of Turkish Astronomers in the Period of 1980-2010
S. Bilir, E. Gogus, O. Onal +2
We investigated the development of astronomy and astrophysics research productivity in Turkey in terms of publication output and their impacts as reflected in the Science Citation…
Local stellar kinematics from RAVE data: III. Radial and Vertical Metallicity Gradients based on Red Clump Stars
S. Bilir, S. Karaali, S. Ak +5
We investigate radial and vertical metallicity gradients for a sample of red clump stars from the RAdial Velocity Experiment (RAVE) Data Release 3. We select a total of 6781 stars,…