Search Publications
Exploring the cosmological model in f(R ,Tϕ) gravity with observational constraints
Bhardwaj, Vinod Kumar; Garg, Priyanka
We have investigated an isotropic and homogeneous cosmological model of the universe in f(R ,Tϕ) gravity, where Tϕ is the trace of the energy-momentum tensor and R is the Ricci scalar. We developed and presented exact solutions of field equations of the proposed model by taking the parametrization q(z) = α + βz/1 + z , where …
Physical and geometrical properties of an Algol type eclipsing binary with a δ Scuti pulsator: HD 221072
Gürol, B.; Özdemir, S.; Gürsoytrak-Mutlay, S. H. +1 more
In this study, we obtained physical and geometrical parameters of an Algol type eclipsing binary hosting a δ Scuti pulsator. Based on the Transiting Exoplanet Survey Satellite (TESS) observations of HD 221072 system published in Sectors 24, 57, and 58, we obtained the photometric solution of the eclipsing binary. The light curve modelling reveals …
BD UMi: Eccentric detached binary with γ Doradus type component
Gürol, Birol
BD UMi is an Algol-type eccentric eclipsing binary with one of the components showing γ Doradus type pulsation. In this study we used the Transiting Exoplanet Survey Satellite (TESS) observations of the BD UMi system published in total of 16 sectors. We obtained the minima times of the eclipsing system and refined new light elements by using (O - …
Kinematical and ellipsoidal properties of the inner-halo hot subdwarfs observed in Gaia DR3 and LAMOST DR7
Elsanhoury, W. H.
Studying the kinematics of inner-halo hot subdwarfs with Gaia DR3 and LAMOST DR7. Three sets of program stars were considered including subsections namely sdB and sdO. Estimating their inner kinematics and velocity ellipsoid parameters. Determine the average local Galactic rotational constants (i.e., Oort's constants).
Resolving the pulsation contents of 13 δ Scuti stars with TESS and K2
Zhou, Ai-Ying
Using the TESS and Kepler K2 light curve archives, I have reanalyzed 13 known δ Scuti stars. AD Ari is now reclassified as a rotating ellipsoidal binary variable. EX Cnc and HD 73712 are reclassified as hybrid δ Sct-γ Dor pulsators. EX Cnc turns out to be an enticing asteroseismic target because of its three distinct groups of pulsation frequencie…
Photometric study of the overcontact binary NSVS2910034
Tobin, R. Wes; Berrington, Robert C.
We present BVRC+TESS differential photometry of an eclipsing binary system NSVS 2910034. A period analysis reveals unusual variations that are inconsistent with systemic orbital period changes and may be due to surface activity. The best fit models are consistent with a W-type W UMa overcontact binary, consisting of a less massive G7 spectral type…
Exploring the physical properties of the γ Dor binary star RX Dra with photometry and asteroseismology
Liao, Wen-Ping; Zeng, Qi-Huan; Li, Ping +2 more
We model the TESS light curve of the binary system RX Dra, and also first calculate a lot of theoretical models to fit the g-mode frequencies previously detected from the TESS series of this system. The mass ratio is determined to be q=0.9026‑0.0032+0.0032. We newly found that there are 16 frequencies (F1–F7, F11–F20) identified as dipole g-modes,…
First photometric study of W UMa-type binary systems: BK Vul and V699 Cep
Soydugan, E.; Adalalı, S.
In this study, new CCD photometric observations and photometric analysis of BK Vul and V699 Cep systems, which are classified as contact binaries in the literature, are presented. For the V699 Cep, the TESS light curve was also used in the photometric analysis. We determined the basic astrophysical parameters of the BK Vul and V699 Cep systems fro…
Gaia (DR3)-based astronomical analysis of the seven unstudied open star clusters
Tadross, A. L.; Badawy, W. A.; Hendy, Y. H. M. +2 more
The seven open star clusters FSR 0717, FSR 1698, Loden 2313, Ruprecht 49, Majaess 61, Mayer 2, and Teutsch 48, which are located near the Milky Way's Galactic plane are studied in this article using the Gaia DR3 dataset. The estimated numbers of potential cluster members are 102, 362, 285, 197, 95, 116, 160, and 397, correspondingly. The calculate…
The improved component masses and parallaxes for the two close binary stars: HD80671 and HD97038
Masda, Suhail
We present the fundamental stellar parameters, including the individual component masses, as well as the orbital parameters, and dynamical parallaxes of the two close binary stars; HD80671, and HD97038. The stellar parameters are spectrophotometrically estimated via Al-Wardat's method for analyzing binary and multiple stellar systems, which is hav…