Yazar "Tanriver, M." seçeneğine göre listele

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  • [ X ]
    Öğe
    A Combined TESS and Ground-based Study of Transit Timing Variations in HAT-P-16, TOI-1516 and TOI-2046 Systems
    (Iop Publishing Ltd, 2025) Sonbas, E.; Kaplan, K.; Tanriver, M.; Keskin, A.; Dhuga, K.; Bulut, A.; Gogus, E.
    We present new results for the hot Jupiters HAT-P-16b, TOI-1516b, and TOI-2046b, based on photometric observations collected using both space- and ground-based facilities. Ground-based data were collected in the 2020-2024 time span with the 0.6 m telescope (ADYU60) located at the Adiyaman University Application and Research Center (Adiyaman, T & uuml;rkiye) and the 1.0 m telescope at the T & uuml;rkiye National Observatory (TUG, T & uuml;rkiye). Through a combination of fits to our ground-based data, the midtransit times data from TESS, and additional data taken from the literature, we present an updated linear ephemeris for each system. Transit timing variations (TTVs) were analyzed using linear, orbital decay, and apsidal precession models. The resulting BIC(Delta BIC) values indicate that the orbital decay model is statistically favored for HAT-P-16b and TOI-1516b, while the constant period model is preferred for TOI-2046b. False alarm probabilities (FAPs) were computed to assess the significance of any periodic signals. TOI-1516b displays a strong TTV signal with a FAP (of 0.0001) well below the 0.01 threshold, suggesting a likely dynamical origin that warrants further investigation. The higher FAP value (0.0055) for HAT-P-16b suggests that the case of a possible presence of an additional body in the system is less convincing. In contrast, the much higher FAP value (0.0196) for TOI-2046b implies that there are no statistically significant TTVs.
  • [ X ]
    Öğe
    On the light curve variation of the Be star EM Cep
    (Astronomical Soc Pacific, 2007) Bakis, H.; Bakis, V.; Demircan, O.; Budding, E.; Tanriver, M.
    We present new UBV photometric observations obtained in the last four observing seasons and one season of spectroscopic observation for the Be star EM Cep. A possible period of 0.403 days and large light amplitude variations from one season to other were determined from the new photometric observations. A flare activity for this star has been detected on 17-18 July 2003. The brightness increase during the flare was found to be maximum in U-band. New spectroscopic observations with high-resolution spectrograph did not present a certain result due to the limited number of data. The type of variability in the light curves shows that the star could be a lambda Eri-type variable. Additional changes on the light curve do not show any periodicity. Binarity problem of the star has been also discussed.