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Your search keyword '"Pavlovski, K."' showing total 25 results
Start Over Author "Pavlovski, K." Publisher oxford university press (oup)
25 results on '"Pavlovski, K."'

5. Evidence for conservative mass transfer in the classical Algol system δ Librae from its surface carbon-to-nitrogen abundance ratio

Author

Dervişoğlu, A, Pavlovski, K, Lehmann, H, Southworth, J, Bewsher, Danielle, Dervişoğlu, A, Pavlovski, K, Lehmann, H, Southworth, J, and Bewsher, Danielle

Abstract

Algol-type binary systems are the product of rapid mass transfer between the initially more massive component to its companion. It is still unknown whether the process is conservative, or whether substantial mass is lost from the system. The history of a system prior to mass exchange is imprinted in the photospheric chemical composition, in particular in the carbon-to-nitrogen (C/N) ratio. We use this to trace the efficiency of mass-transfer processes in the components of a classical Algol-type system, δ Librae. The present analysis is based on new spectroscopic data (ground-based high-resolution échelle spectra) and extracted archival photometric observations (space-based measurements from the STEREO satellites). In the orbital solution, non-Keplerian effects on the radial-velocity variations were taken into account. This reduces the primary’s mass by 1.1 M⊙ (∼23%) significantly in comparison to previous studies, and removes a long-standing discrepancy between the radius and effective temperature. A spectral disentangling technique is applied to the échelle observations and the spectra of the individual components are separated. Atmospheric and abundance analyses are performed for the mass-gaining component and we found C/N =1.55 ± 0.40 for this star. An extensive set of evolutionary models (3.5 × 106) for both components are calculated from which the best-fitting model is derived. It is found that β, the parameter which quantifies the efficiency of mass-loss from a binary system, is close to zero. This means that the mass-transfer in δ Lib is mostly conservative with little mass loss from the system.

Published
2018

9. A quintuple star system containing two eclipsing binaries

Author

Rappaport, S., primary, Lehmann, H., additional, Kalomeni, B., additional, Borkovits, T., additional, Latham, D., additional, Bieryla, A., additional, Ngo, H., additional, Mawet, D., additional, Howell, S., additional, Horch, E., additional, Jacobs, T. L., additional, LaCourse, D., additional, Sódor, Á., additional, Vanderburg, A., additional, and Pavlovski, K., additional

Published
2016
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10. Stellar modelling of Spica, a high-mass spectroscopic binary with a β Cep variable primary component

Author

Tkachenko, A., primary, Matthews, J. M., additional, Aerts, C., additional, Pavlovski, K., additional, Pápics, P. I., additional, Zwintz, K., additional, Cameron, C., additional, Walker, G. A. H., additional, Kuschnig, R., additional, Degroote, P., additional, Debosscher, J., additional, Moravveji, E., additional, Kolbas, V., additional, Guenther, D. B., additional, Moffat, A. F. J., additional, Rowe, J. F., additional, Rucinski, S. M., additional, Sasselov, D., additional, and Weiss, W. W., additional

Published
2016
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11. Spectroscopically resolving the Algol triple system

Author

Kolbas, V., primary, Pavlovski, K., additional, Southworth, J., additional, Lee, C.-U., additional, Lee, D.-J., additional, Lee, J. W., additional, Kim, S.-L., additional, Kim, H.-I., additional, Smalley, B., additional, and Tkachenko, A., additional

Published
2015
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12. HD 183648: a Kepler eclipsing binary with anomalous ellipsoidal variations and a pulsating component

Author

Borkovits, T., Derekas, A., Fuller, J., Szabo, G. M., Pavlovski, K., Csak, B., Dozsa, A., Kovacs, J., Szabo, R., Hambleton, K. M., Kinemuchi, K., Kolbas, V., Kurtz, D. W., Maloney, F., Pr a, A., Southworth, J., Sztakovics, J., Biro, I. B., Jankovics, I., Borkovits, T., Derekas, A., Fuller, J., Szabo, G. M., Pavlovski, K., Csak, B., Dozsa, A., Kovacs, J., Szabo, R., Hambleton, K. M., Kinemuchi, K., Kolbas, V., Kurtz, D. W., Maloney, F., Pr a, A., Southworth, J., Sztakovics, J., Biro, I. B., and Jankovics, I.

Abstract

KIC 8560861 (HD 183648) is a marginally eccentric (e =0.05) eclipsing binary with an orbital period of Porb = 31.973 d, exhibiting mmag amplitude pulsations on time-scales of a few days. We present the results of the complex analysis of high- and medium-resolution spectroscopic data and Kepler Q0 – Q16 long cadence photometry. The iterative combination of spectral disentangling, atmospheric analysis, radial velocity and eclipse timing variation studies, separation of pulsational features of the light curve, and binary light curve analysis led to the accurate determination of the fundamental stellar parameters. We found that the binary is composed of two main-sequence stars with an age of 0.9 ± 0.2 Gyr, having masses, radii and temperatures of M1 = 1.93 ± 0.12 M⊙, R1 = 3.30 ± 0.07 R⊙, Teff1 = 7650 ± 100 K for the primary, and M2 = 1.06 ± 0.08 M⊙, R2 = 1.11 ± 0.03 R⊙, Teff2 = 6450 ± 100 K for the secondary. After substracting the binary model, we found three independent frequencies, two of which are separated by twice the orbital frequency. We also found an enigmatic half orbital period sinusoidal variation that we attribute to an anomalous ellipsoidal effect. Both of these observations indicate that tidal effects are strongly influencing the luminosity variations of HD 183648. The analysis of the eclipse timing variations revealed both a parabolic trend, and apsidal motion with a period of Pobs apse = 10 400 ± 3 000 y, which is ten times faster than what is theoretically expected. These findings might indicate the presence of a distant, unseen companion.

Published
2014

14. HD 183648: a Kepler eclipsing binary with anomalous ellipsoidal variations and a pulsating component

Author

Borkovits, T., primary, Derekas, A., additional, Fuller, J., additional, Szabó, Gy. M., additional, Pavlovski, K., additional, Csák, B., additional, Dózsa, Á., additional, Kovács, J., additional, Szabó, R., additional, Hambleton, K. M., additional, Kinemuchi, K., additional, Kolbas, V., additional, Kurtz, D. W., additional, Maloney, F., additional, Prša, A., additional, Southworth, J., additional, Sztakovics, J., additional, Bíró, I. B., additional, and Jankovics, I., additional

Published
2014
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19. Detection of gravity modes in the massive binary V380 Cyg from Kepler space-based photometry and high-resolution spectroscopy★

Author

Tkachenko, A., primary, Aerts, C., additional, Pavlovski, K., additional, Southworth, J., additional, Degroote, P., additional, Debosscher, J., additional, Still, M., additional, Bryson, S., additional, Molenberghs, G., additional, Bloemen, S., additional, de Vries, B. L., additional, Hrudkova, M., additional, Lombaert, R., additional, Neyskens, P., additional, Pápics, P. I., additional, Raskin, G., additional, Van Winckel, H., additional, Morris, R. L., additional, Sanderfer, D. T., additional, and Seader, S. E., additional

Published
2012
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21. Kepler photometry of KIC 10661783: a binary star with total eclipses and δ Scuti pulsations

Author

Southworth, John, primary, Zima, W., additional, Aerts, C., additional, Bruntt, H., additional, Lehmann, H., additional, Kim, S.-L., additional, Kurtz, D. W., additional, Pavlovski, K., additional, Prša, A., additional, Smalley, B., additional, Gilliland, R. L., additional, Christensen-Dalsgaard, J., additional, Kawaler, S. D., additional, Kjeldsen, H., additional, Cote, M. T., additional, Tenenbaum, P., additional, and Twicken, J. D., additional

Published
2011
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24. The rest-frame optical colours of 99 000 Sloan Digital Sky Survey galaxies

Author

Smolčić, V., primary, Ivezić, Ž., additional, Gaćeša, M., additional, Rakos, K., additional, Pavlovski, K., additional, Ilijić, S., additional, Obrić, M., additional, Lupton, R. H., additional, Schlegel, D., additional, Kauffmann, G., additional, Tremonti, C., additional, Brinchmann, J., additional, Charlot, S., additional, Heckman, T. M., additional, Knapp, G. R., additional, Gunn, J. E., additional, Brinkmann, J., additional, Csabai, I., additional, Fukugita, M., additional, and Loveday, J., additional

Published
2006
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25. A photometric campaign on the Be stars o And, KX And, KY And, LQ And and EW Lac

Author

Stagg, C. R., primary, Bo i , H., additional, Fullerton, A. W., additional, Gao, W. S., additional, Guo, Z. H., additional, Harmanec, P., additional, Horn, J., additional, Huang, L., additional, Iliev, L. H., additional, Koubsky, P., additional, Kovachev, B. Z., additional, Pavlovski, K., additional, Percy, J. R., additional, Schmidt, F., additional,  tefl, S., additional, Tomov, N. A., additional, and  i  ovsky, J., additional

Published
1988
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