The chromospherically active binary CF Tuc revisited
| dc.contributor.author | Dogru, D. | |
| dc.contributor.author | Erdem, A. | |
| dc.contributor.author | Dogru, S. S. | |
| dc.contributor.author | Zola, S. | |
| dc.date.accessioned | 2025-01-27T20:55:59Z | |
| dc.date.available | 2025-01-27T20:55:59Z | |
| dc.date.issued | 2009 | |
| dc.department | Çanakkale Onsekiz Mart Üniversitesi | |
| dc.description.abstract | This paper presents results derived from analysis of new spectroscopic and photometric observations of the chromospherically active binary system CF Tuc. New high-resolution spectra, taken at the Mt. John University Observatory in 2007, were analysed using two methods: cross-correlation and Fourier-based disentangling. As a result, new radial velocity curves of both components were obtained. The resulting orbital elements of CF Tuc are a(1) sin i = 0.0254 +/- 0.0001 au, a(2) sin i = 0.0228 +/- 0.0001 au, M-1 sin i = 0.902 +/- 0.005 M-circle dot and M-2 sin i = 1.008 +/- 0.006 M-circle dot. The cooler component of the system shows H alpha and Ca ii H&K emissions. Using simultaneous spectroscopic and photometric observations, an anticorrelation between the H alpha emission and the BV light curve maculation effects was found. This behaviour indicates a close spatial association between photospheric and chromospheric active regions. Our spectroscopic data and recent BV light curves were solved simultaneously using the Wilson-Devinney code. A dark spot on the surface of the cooler component was assumed to explain large asymmetries observed in the light curves. The following absolute parameters of the components were determined: M-1 = 1.11 +/- 0.01 M-circle dot, M-2 = 1.23 +/- 0.01 M-circle dot, R-1 = 1.63 +/- 0.02 R-circle dot, R-2 = 3.60 +/- 0.02 R-circle dot, L-1 = 3.32 +/- 0.51 L-circle dot and L-2 = 3.91 +/- 0.84 L-circle dot. The primary component has an age of about 5 Gyr and is approaching its main-sequence terminal age. The distance to CF Tuc was calculated to be 89 +/- 6 pc from the dynamic parallax, neglecting interstellar absorption, in agreement with the Hipparcos value. The orbital period of the system was studied using the O-C analysis. The O-C diagram could be interpreted in terms of either two abrupt changes or a quasi-sinusoidal form superimposed on a downward parabola. These variations are discussed by reference to the combined effect of mass transfer and mass loss, the Applegate mechanism and also a light-time effect due to the existence of a third body in the system. | |
| dc.description.sponsorship | University Research Foundation [2007/55] | |
| dc.description.sponsorship | This study is related to the Southern Binary Project of the Astrophysics Research Centre at Canakkale Onsekiz Mart University, the Carter National Observatory and the MJUO in New Zealand. It also forms part of the PhD thesis of DD and was supported by Canakkale Onsekiz Mart University Research Foundation under grant no. 2007/55. We thank Professor John Hearnshaw for granting use of the observing facilities at MJUO. We also thank J. L. Innis for making his data available. DD thanks Professor Edwin Budding, Dr Faruk Soydugan and Dr Hasan Ak for their useful comments and suggestions. Discussions with M. Balucinska-Church and J.-P. Lasota were greatly appreciated. We also thank the anonymous referee for the comments which helped us to improve the quality of this paper. | |
| dc.identifier.doi | 10.1111/j.1365-2966.2009.15072.x | |
| dc.identifier.endpage | 1660 | |
| dc.identifier.issn | 0035-8711 | |
| dc.identifier.issn | 1365-2966 | |
| dc.identifier.issue | 3 | |
| dc.identifier.scopus | 2-s2.0-68149138676 | |
| dc.identifier.scopusquality | Q1 | |
| dc.identifier.startpage | 1647 | |
| dc.identifier.uri | https://doi.org/10.1111/j.1365-2966.2009.15072.x | |
| dc.identifier.uri | https://hdl.handle.net/20.500.12428/26266 | |
| dc.identifier.volume | 397 | |
| dc.identifier.wos | WOS:000268459900041 | |
| dc.identifier.wosquality | Q1 | |
| dc.indekslendigikaynak | Web of Science | |
| dc.indekslendigikaynak | Scopus | |
| dc.language.iso | en | |
| dc.publisher | Oxford Univ Press | |
| dc.relation.ispartof | Monthly Notices of The Royal Astronomical Society | |
| dc.relation.publicationcategory | info:eu-repo/semantics/openAccess | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.snmz | KA_WoS_20250125 | |
| dc.subject | techniques: photometric | |
| dc.subject | techniques: spectroscopic | |
| dc.subject | binaries: eclipsing | |
| dc.subject | stars: fundamental parameters | |
| dc.subject | stars: individual: CF Tuc | |
| dc.title | The chromospherically active binary CF Tuc revisited | |
| dc.type | Article |
