39 citations · 346 across the 22 of their papers we have counts for
22 papers
The Mirya-m1 Cosmic Ray Detector: Features and First Year Observations
Meryem Kubra Dag, Tolga Guver, Guray Gurkan +9
We introduce the Mirya-m1 Cosmic Ray Detector, the largest and only cosmic ray detector in Turkiye designed for space weather research. Mirya-m1, modeled and built after the Muon I…
A Detailed Spectral Study of Intermittent-Accreting Millisecond X-ray Pulsar Aql X-1 during Pulse-on and Pulse-off Stages
T. Kocabıyık, C. Güngör, M. T. Sağlam +2
We present a detailed spectral study of an intermittent-AMXP Aql X-1 during the pulse-on and pulse-off stages by using the archival RXTE data. We first perform temporal analysis by…
Burst-Disk Interaction in 4U 1636-536 as observed by NICER
Tolga Guver, Funda Bostanci, Tugba Boztepe +10
We present the detection of 51 thermonuclear X-ray bursts observed from 4U 1636-536 by the Neutron Star Interior Composition Explorer (NICER) over the course of a three year monito…
A NICER look at thermonuclear X-ray bursts from Aql X-1
Tolga Guver, Tugba Boztepe, David R. Ballantyne +8
We present spectral and temporal properties of all the thermonuclear X-ray bursts observed from Aql X-1 by the Neutron Star Interior and Composition Explorer (NICER) between 2017 J…
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…
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…
Metallicity Calibration and Photometric Parallax Estimation: II. SDSS photometry
S. Tuncel Guctekin, S. Bilir, S. Karaali +4
We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess, defined with d…
Local Stellar Kinematics from RAVE data - VII. Metallicity Gradients from Red Clump Stars
O. Onal Tas, S. Bilir, G. M. Seabroke +4
We investigate the Milky Way Galaxy's radial and vertical metallicity gradients using a sample of 47,406 red clump stars from the RAVE DR4. This sample is more than twice the size…
CCD UBV Photometry and Kinematics of the Open Cluster NGC 225
S. Bilir, Z. F. Bostanci, T. Yontan +6
We present the results of CCD photometric and spectroscopic observations of the open cluster NGC 225. In order to determine the structural parameters of NGC 225, we calculate…
Metallicity Calibration and Photometric Parallax Estimation: I. UBV photometry
S. Tuncel Guctekin, S. Bilir, S. Karaali +3
We present metallicity and photometric parallax calibrations for the F and G type dwarfs with photometric, astrometric and spectroscopic data. The sample consists of 168 dwarf star…
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…
Local Stellar Kinematics from RAVE data - VI. Metallicity Gradients Based on the F-G Main-sequence Stars
O. Plevne, T. Ak, S. Karaali +3
We estimated iron and metallicity gradients in the radial and vertical directions with the F and G type dwarfs taken from the RAVE DR4 database. The sample defined by the constrain…
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…
Local stellar kinematics from RAVE data: IV. Solar neighbourhood age-metallicity relation
S. Duran, S. Ak, S. Bilir +4
We investigated the age-metallicity relation using a sample of 5691 F and G type dwarfs from RAVE DR3 by applying several constraints: i) We selected stars with surface gravities l…
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…
Gamma Ray Bursts with Extended Emission Observed with BATSE
Zahide Funda Bostanci, Yuki Kaneko, Ersin Gogus
We present the results of our systematic search for extended emission components following initial short gamma-ray burst (GRB) spikes, using Burst and Transient Source Experiment (…
Cloud Modeling of a Network Region in H-alpha
Z. F. Bostanci
In this paper, we analyze the physical properties of dark mottles in the chromospheric network using two dimensional spectroscopic observations in H-alpha obtained with the Gotting…
Cloud modeling of a quiet solar region in H-alpha
Z. F. Bostanci, N. Al Erdogan
We present chromospheric cloud modeling on the basis of H-alpha profile-sampling images taken with the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope…
Temporal evolution of mottles observed in H_alpha
Z. Funda Bostanci, Nurol Al Erdogan
In April 2002, H_alpha observations of the solar chromosphere with high spatial and spectral resolution were obtained with the Gottingen Fabry-Perot Spectrometer mounted in the Vac…