Faruk Soydugan

Faruk Soydugan
Çanakkale Onsekiz Mart Üniversitesi | ÇOMÜ · Department of Physics & Astrophysics Research Center and Observatory

PhD

About

109
Publications
6,193
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1,119
Citations
Additional affiliations
May 2014 - present
Çanakkale Onsekiz Mart Üniversitesi
Position
  • Professor

Publications

Publications (109)
Preprint
Full-text available
Arbitrariness in the zero point of bolometric corrections is a nearly century-old paradigm leading to two more paradigms. "Bolometric corrections must always be negative," and "bolometric magnitude of a star ought to be brighter than its $V$ magnitude". Both were considered valid before IAU 2015 General Assembly Resolution B2, a revolutionary docum...
Article
Full-text available
In this first study, which is aimed to regularly examine the annual publication performances of the Turkish institutions conducting research in the fields of astronomy and astrophysics. The time frame of 2020 was selected for this investigation and 135 scientific articles published by researchers from Turkey in journals included in Science Citation...
Article
Full-text available
We present the results of a temporal and spectral analysis of the transient source ULX-4 in the galaxy M51. The data used were drawn from Chandra, XMM-Newton and Swift-XRT archives, spanning the years 2000-2019. The X-ray flux of the source is seen to vary by two orders of magnitudes within a month but a short-term variability was not observed over...
Article
Methods of obtaining stellar luminosities (L) have been revised and a new concept, standard stellar luminosity, has been defined. In this paper, we study three methods: (i) a direct method from radii and effective temperatures; (ii) a method using a mass–luminosity relation (MLR); and (iii) a method requiring a bolometric correction. If the unique...
Preprint
Full-text available
Methods of obtaining stellar luminosities (L) have been revised and a new concept, standard stellar luminosity, has been defined. Among the three methods (direct method from radii and effective temperatures, method using a mass-luminosity relation (MLR), and method requiring a bolometric correction), the third method, which uses the unique bolometr...
Preprint
We present the results of a temporal and spectral analysis of the transient source ULX-4 in the galaxy M51. The data used were drawn from {\it Chandra}, {\it XMM-Newton} and {\it XRT} archives, spanning the years 2000-2019. The X-ray flux of the source is seen to vary by two orders of magnitudes within a month but a short-term variability was not o...
Article
Arbitrariness attributed to the zero point constant of the V band bolometric corrections (BCV) and its relation to “bolometric magnitude of a star ought to be brighter than its visual magnitude” and “bolometric corrections must always be negative” was investigated. The falsehood of the second assertion became noticeable to us after IAU 2015 General...
Preprint
Full-text available
Arbitrariness attributed to the zero point constant of the $V$ band bolometric corrections ($BC_V$) and its relation to "bolometric magnitude of a star ought to be brighter than its visual magnitude" and "bolometric corrections must always be negative" was investigated. The falsehood of the second assertion became noticeable to us after IAU 2015 Ge...
Article
Full-text available
In this study, we report identification of a new ultraluminous X-ray source (ULX) named as X-7 in NGC 1316, with an unabsorbed luminosity of 2.1 × 1039 erg s−1 using the two recent Chandra archival observations. The X-7 was detected in the Chandra 2001 observation and was included in the source list of the NGC 1316 as CXOUJ032240.8−371224 with a lu...
Preprint
In this study, investigation of two double-lined binary stars KIC 5113146 and KIC 5111815 in NGC 6819 is presented based on both photometric and spectroscopic data. Simultaneous analysis of light and radial velocity curves was made and the absolute parameters of the systems' components were determined for the first time. We find that both systems h...
Article
Nearby detached double-lined eclipsing binaries with most accurate data were studied and 290 systems were found with at least one main-sequence component having a metallicity of 0.008 ≤ Z ≤ 0.040. Stellar parameters, light ratios, Gaia Data Release 2 trigonometric parallaxes, extinctions and/or reddening were investigated and only 206 systems were...
Preprint
Full-text available
In this study, we report identification of a new ultraluminous X-ray source (ULX) which we named as X-7 in NGC 1316, with an unabsorbed luminosity of 2.10$\times$10$^{39}$ erg s$^{-1}$ using two recent {\it Chandra} archival observations. The X-7 was detected in the {\it Chandra} 2001 observation and it was included in the X-ray source list of the...
Preprint
Nearby detached double-lined eclipsing binaries with most accurate data were studied and 290 systems were found with at least one main-sequence component having a metallicity $0.008\leq Z\leq 0.040$. Stellar parameters, light ratios, Gaia DR2 trigonometric parallaxes, extinctions and/or reddening were investigated and only 206 systems were selected...
Article
W UMi is a near contact, semi-detached, double-lined eclipsing binary star with an orbital period of 1.7 d. Simultaneous analysis of new BV R multi-color light curves and radial velocity data yields the main astrophysical parameters of the binary and its component stars. We determined mass and radius to be M 1 = 3.22 ± 0.08 M ⊙ , R 1 = 3.63 ± 0.04...
Preprint
Full-text available
W UMi is a near contact, semi-detached, double-lined eclipsing binary star with an orbital period of 1.7 days. Simultaneous analysis of new BVR multi-color light curves and radial velocity data yields the main astrophysical parameters of the binary and its component stars. We determined mass and radius to be M$_{1}$=3.22$\pm$0.08 M$_{\odot}$, R$_{1...
Article
In this study, new photometric observations of shallow contact binary CN Andromedae (CN And) were performed and multi-color (BV R) CCD light curves (LCs) were obtained. Simultaneous analysis of new LCs and published radial velocity (RV) data reveals that the system is an early contact binary in which both components have recently filled their inner...
Conference Paper
Conventional mass-luminosity (M – L) relations are defined using 509 nearby main-sequence (MS) stars within the Solar neighborhood. A smooth mass-radius (M – R) relation was fixed from radii of MS stars appeared in literature having masses within the limits 0.179 – 1.5 M⊙. Similarly, a smooth mass-effective temperature (M – Teff) relation was deriv...
Article
Absolute parameters of 509 main-sequence stars selected from the components of detached-eclipsing spectroscopic binaries in the Solar neighbourhood are used to study mass-luminosity, mass-radius and mass-effective temperature relations (MLR, MRR and MTR). The MLR function is found better if expressed by a six-piece classical MLR (L∝Mα) rather than...
Preprint
Full-text available
Absolute parameters of 509 main-sequence stars selected from the components of detached-eclipsing spectroscopic binaries in the Solar neighbourhood are used to study mass-luminosity, mass-radius and mass-effective temperature relations (MLR, MRR and MTR). The MLR function is found better if expressed by a six-piece classical MLR ($L \propto M^{\alp...
Article
We present analyses of the transit light curves and transit time measurements of the exoplanets HAT-P-3b, HD 189733b, and WASP-43b. Transit light curves were collected at Çanakkale Onsekiz Mart University Observatory and TÜBİTAK National Observatory. The models were produced by WINFITTER code and stellar, planetary, and orbital properties were obta...
Article
In this study, we present solutions of the transit light curves of the recently discovered exoplanet Kepler-485b observed by the Kepler space telescope. To obtain stellar, planetary, and orbital properties, WINFITTER code was applied to transit light curve data, which are available at the NASA Exoplanet Archive (NEA).
Article
New photometric follow-up observations of transitting ‘hot Jupiters’ TrES-3b and Qatar-1b are presented. Weighted mean values of the solutions of light curves in R-filter for both planetary systems are reported and compared with the previous results. The transit light curves were analysed using the winfitter code. The physical properties of the pla...
Conference Paper
Full-text available
In this study, we investigated orbital period variations of two low mass ratio contact binaries GR Vir and FP Boo based on published minima times. From the O-C analysis, it was found that FP Boo indicates orbital period decrease while the period of GR Vir is increasing. Mass transfer process was used to explain increase and decrease in the orbital...
Conference Paper
We present solutions of the transit light curves and transit timing variations (TTVs) analyses of the exoplanets HAT-P-5b, HAT-P-9b and HAT-P-25b. Transit light curves were collected at Çanakkale Onsekiz Mart University Observatory and TUBITAK National Observatory. The models were produced by WINFITTER program and stellar, planetary and orbital pro...
Conference Paper
In this study, we present solutions of the transit light curves of the recently discovered planet Kepler-491b observed by Kepler space-telescope within a span of four years. In order to obtain stellar, planetary and orbital properties, WINFITTER code was applied to light curve data available at the NASA ExoplanetArchive (NEA). We also searched for...
Conference Paper
Stars are one of the most important objects to understand how the galaxies are formed, shaped and evolved. Hence, the determination of the absolute parameters of stars plays a crucial role. The absolute parameters (e.g. mass and radii) of the detached eclipsing binary stars could be determined with well accuracy. These accurate parameters could be...
Conference Paper
In this study, we present light curve analysis of a southern contact binary SY Hor. Photometric parameters of the system and its components are derived using the Wilson and Devinney code based on the data taken from the SuperWASP public data archive. Photometric solutions indicate that SY Hor is a marginal contact binary system with a mass ratio of...
Conference Paper
Contact binary stars have an important role to understand how the binary stars evolve to a single star and explain to the physical processes of star merges. Hence, understanding of different type of contact binaries is valuable to explore some physical processes such as angular momentum loses, mass and heat transfers between components. In this stu...
Conference Paper
In this study, we investigated orbital period variations of two contact binaries V343 Ori and FZ Ori based on published minima times. Using the O-C analysis, it was found that both systems indicate orbital period increase. Mass transfer from less massive component to more massive component was used to explain increases in the orbital periods. On th...
Conference Paper
In this study, we investigated orbital period changes of three contact binaries DK Cyg, VW Boo and CV Cyg. From O-C analysis, it was found that DK Cyg indicates orbital period increase, whereas the periods of CV Cyg and VW Boo are decreasing. For DK Cyg, mass transfer from less massive component to more massive one was used to explain the variation...
Article
New CCD photometric observations of the neglected classical Algol-type binary XZ Aql were obtained over 53 nights during the observing season of 2011. Photometric elements were determined from analysis of multi-colour light curves. This first comprehensive investigation of the system revealed that the system is in semi-detached configuration with a...
Article
Full-text available
The young binary system HD 350731 is a noteworthy laboratory for studying early-type binaries with similar components. We present here the analysis of differential multi-color photometric and spectroscopic observations for the double-lined detached system. Accurate absolute parameters were determined from the simultaneous solution of light and radi...
Article
Full-text available
Kinematical properties of CVs were investigated according to population types and orbital periods, using the space velocities computed from recently updated systemic velocities, proper motions and parallaxes. Reliability of collected space velocity data are refined by removing 34 systems with largest space velocity errors. The 216 CVs in the refine...
Article
Full-text available
The mass-luminosity (M-L), mass-radius (M-R) and mass-effective temperature ($M-T_{eff}$) diagrams for a subset of galactic nearby main-sequence stars with masses and radii accurate to $\leq 3\%$ and luminosities accurate to $\leq 30\%$ (268 stars) has led to a putative discovery. Four distinct mass domains have been identified, which we have tenta...
Conference Paper
Full-text available
In this study, the distributions of the double-lined detached binaries (DBs) on the planes of mass-luminosity, mass radius and mass-effective temperature have been studied. We improved the classical mass-luminosity relation based on the database of DBs by Eker et al. (2004a). With accurate observational data available to us, a method for improving...
Article
This study presents analysis of new multi-band light curves of β Lyrae-type eclipsing binary SX Aur. Radial velocities of both components of the system were collected from the literature and simultaneous light curve solutions made to determine the properties of the system and absolute elements of its components. The derived masses and radii of the...
Article
Full-text available
The most accurate stellar astrophysical parameters were collected from the solutions of the light and the radial velocity curves of 257 detached double-lined eclipsing binaries in the Milky Way. The catalogue contains masses, radii, surface gravities, effective temperatures, luminosities, projected rotational velocities of the component stars, and...
Article
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 radial velocities enabled us to derive the absolute parameters of the components. The simultaneous light and radial velocity curves solution yields masses and radii of \e...
Article
In this work, we present the photometric study of A-type contact binaries V1073 Cyg and V357 Peg. The simultaneous solutions of BVR light and radial velocity curves of the systems are given. During the analysis of the light curves of V357 Peg, we have used two models included hot and dark spots. The third light contribution was also found for V357...
Article
In this work, we present the photometric study of A-type contact binaries V1073 Cyg and V357 Peg. The simultaneous solutions of BVR light and radial velocity curves of the systems are given. During the analysis of the light curves of V357 Peg, we have used two models included hot and dark spots. The third light contribution was also found for V357...
Article
Full-text available
This paper presents results from analysing spectroscopic and multicolour photometric observations of the neglected semi-detached eclipsing binary system IO Ursae Majoris (IO UMa). For the first time, the orbital parameters of the system and fundamental physical properties of its components were determined from simultaneous analysis of BVR light cur...
Article
Full-text available
This paper presents high resolution spectroscopy of the HX Vel (IDS 08390-4744 AB) multiple system. New spectroscopic observations of the system were made at Mt. John University Observatory in 2007 and 2008. Radial velocities of both components of HX Vel A were measured using gaussian fitting. The spectroscopic mass ratio of the close binary was de...
Article
Full-text available
The kinematic behaviour of 362 chromospherically active binary stars (CABs) in the solar neighbourhood were investigated. The Third CABs Catalog by Eker et al. (2008) was used as the main source. The spatial distribution and the components of the Galactic space velocities of the programme stars were determined. The effects of differential rotation...
Article
Full-text available
The orbital angular momenta OAM (J) of detached binaries (including both cool and hot binaries) were estimated and nine subgroups were formed according to their OAM (J) distribution. The mean kinematical ages of all subgroups have been estimated by using their space velocity distributions and, thus, the age dependent variations of the mean OAM (J),...
Data
This paper presents high resolution spectroscopy of the HX Vel (IDS 08390-4744 AB) multiple system. New spectroscopic observations of the system were made at Mt. John University Observatory in 2007 and 2008. Radial velocities of both components of HX Vel A were measured using gaussian fitting. The spectroscopic mass ratio of the close binary was de...
Article
This paper presents new CCD Bessell BVRI light curves and photometric analysis of the Algol-type binary star TX Her. The CCD observations were carried out at Çanakkale Onsekiz Mart University Observatory in 2010. New BVRI light curves from this study and radial velocity curves from Popper (1970) were solved simultaneously using modern light and rad...
Article
This study presents an investigation of the orbital period variations of five Algol type binaries, UX Leo, RW Mon, EQ Ori, XZ UMa and AX Vul based on all available minima times. The O–C diagrams of all systems exhibit a periodic variation superimposed on a downward parabolic segment. The mass loss due to magnetic braking effect in the cooler compon...
Article
This study presents new photometric observations of classical Algol type binary BG Peg with a δ Scuti component. The light curve modeling was provided with the physical parameters of the component stars in the BG Peg system for the first time. After modeling light curves in B and V filters, the eclipse and proximity effects were removed from the li...
Article
Full-text available
We summarize recent work on cool active stars in our programme. We carried out photometry at the Çanakkale Onsekiz Mart University (COMU) observatory, and high-resolution spectroscopy at Mt John University Observatory, as well as collecting data from other facilties. A combination of analysis methods, including our information limit optimization te...
Article
Full-text available
In this study, eclipsing binaries located in the delta Scuti region of the instability strip were chosen from the list of candidate eclipsing binary systems with delta Scuti components. These candidate systems were photometrically observed and some of them were announced to be new Algol-type binaries with delta Scuti components. Although the pulsat...
Article
We investigated the orbital period variations of five neglected Algol-type eclipsing binaries (RW Cet, BO Gem, DG Lac, SW Oph and WY Per) in this study. Their O–C diagrams display tilted sinusoidal variations superimposed on upward parabolic forms. The parabolic variations, which correspond to secular period increases, were interpreted in terms of...
Article
We present new multiband CCD photometric observations of three chromospherically active stars with long periods (V2075 Cyg, FG UMa and BM CVn). The observations were made at the Çanakkale Onsekiz Mart University Observatory in 2006 and 2007. We analyzed BVRI (Bessell) CCD observations of these three RS CVn-type SB1 binaries with the following three...
Article
We present the spectroscopic orbit solutions of three double-lines eclipsing binaries, BG Ind, IM Mon and RS Sgr. The first precise radial velocities (RVs) of the components were determined using high resolution echelle spectra obtained at Mt. John University Observatory in New Zealand. The RVs of the components of BG Ind and RS Sgr were measured u...
Article
We present a photometric study of three chromospherically active stars with long periods (V340 Gem, SAO 62042 and FI Cnc). The observations were made at the ÇOMU Observatory in 2006 and 2007. We have made initial photometric analyses of V340 Gem and SAO 62042, which are newly discovered RS CVn–type SB1 binaries, and established the photometric vari...
Article
Full-text available
We present the first ground-based photometric observations and results of EW Boo. The V light curve obtained over 12 nights in 2006 was analyzed by using the Wilson-Dewinney code. We also found that the primary component of the system shows δ Scuti-type variability.
Article
Full-text available
The long-term orbital period variations of the Algol-type binaries with δ Scuti compo- nent(oEA) AB Cas, CT Her, and TW Dra are investigated. An upward parabola is seen in all of these systems O-C diagrams, as is expected from the evolutionary scenario of clas- sical Algols. In addition to parabolic variations, the periodic variations on the parabo...
Article
Lutz-Kelker bias corrected absolute magnitude calibrations for the detached binary systems with main-sequence components are presented. The absolute magnitudes of the calibrator stars were derived at intrinsic colours of Johnson-Cousins and 2MASS (Two Micron All Sky Survey) photometric systems. As for the calibrator stars, 44 detached binaries were...
Article
The catalogue of chromospherically active binaries (CABs) has been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. The catalogue is available in electronic format where each system has a number of lines (suborders) with a unique order number. The columns contain data of limited numbers of selected cro...
Article
An investigation of the orbital period changes of the neglected eclipsing binaries, RY Aqr, SZ Her, RV Lyr and V913 Oph, is presented based on all published minima times. Although the explanation of magnetic activity on the surface of the secondaries of the studied Algols is still open, the preferred light-time effect due to the unseen components a...
Article
Full-text available
Chromospherically Active Binaries (CAB) catalogue have been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. Catalogue is available in electronic format where each system has various number of lines (sub-orders) with a unique order number. Columns contain data of limited number of selected cross refere...
Article
Full-text available
New photometric observations of the Algol-type binary system AB Cassiopeiae were obtained in B and V filters during the 2001–2002 observing season at Ege University Observatory. As expected, the new light curves of the system, which were analyzed using the Wilson-Devinney code, exhibit short-period oscillations due to pulsation of the primary compo...
Article
Full-text available
The orbital periods of two Algol-type binaries, S Equ and AB Cas, are studied based on all available times of minima. It is found that the O-C variations of both systems can be represented by a parabolic and a periodic term. S Equ has an accretion region due to mass transfer as shown by Richards and coworkers and Richards & Albright. On the other h...
Article
We present the first study of the orbital period variations of five neglected Algol-type eclipsing binaries TT And, V342 Aql, RW Cap, BZ Cas and TW Lac, using their O–C diagrams gathered from all available times of eclipse minima. These O–C diagrams indicate that short term periodic variations superimposed on secular period increases as expected in...
Article
We present and analyse high-resolution optical spectra of two Algol binaries, namely S Equ and KO Aql, obtained with the echelle spectrograph at Catania Astrophysical Observatory. New accurate radial velocities (RVs) for the hotter primary components are obtained. Thanks to the cross-correlation procedure, we were able to measure, for the first tim...
Article
The Hipparcos Space Astrometry Mission photometric observations of V398 Lac, led to the discovery of its variability, allowing to classify it as an eclipsing binary with an orbital period of about 5.4 days. This prompted us to acquire highresolution échelle spectra with the aim of performing accurate radial velocity measurements and to determine th...
Article
For our present study, we have compiled a sample of Algols with well-determined parameters from various literature sources, including the recent catalogue of Budding et al. (2004, Cat. ) which was the core of our sample.
Article
For our present study, we have compiled a sample of Algols with well-determined parameters from various literature sources, including the recent catalogue of Budding et al. (2004, Cat. ) which was the core of our sample. (3 data files).