The near-contact binary star RZ Dra revisited
[ X ]
Tarih
2011
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This paper presents the absolute parameters of RZ Dra. New CCD observations were made at the Mt. Suhora Observatory in 2007. Two photometric data sets (1990 BV and 2007 BVRI) were analysed using modern light-curve synthesis methods. Large asymmetries in the light curves may be explained in terms of a dark starspot on the primary component, an A6 type star. Due to this magnetic activity, the primary component would appear to belong to the class of Ap-stars and would show small amplitude with delta Scuti-type pulsations. With this in mind, a time-series analysis of the residual light curves was made. However, we found no evidence of pulsation behaviour in RZ Dra. Combining the solutions of our light curves and Rucinski et al. (2000)'s radial velocity curves, the following absolute parameters of the components were determined: M(1) = 1.63 +/- 0.03 M(circle dot), M(2) = 0.70 +/- 0.02 M, R(1) = 1.65 +/- 0.02R(circle dot), R(2) = 1.15 +/- 0.02 R(circle dot), L(1) = 9.72 +/- 0.30 L(circle dot) and L(2) = 0.74 +/- 0.10 L(circle dot). The distance to RZ Dra was calculated as 400 +/- 25 pc, taking into account interstellar extinction. The orbital period of the system was studied using updated O-C information. It was found that the orbital period varied in its long-period sinusoidal form, superimposed on a downward parabola. The parabolic term shows a secular period decrease at a slow rate of 0.06 +/- 0.02 s per century and is explained by the mass loss via magnetized wind of the Ap-star primary. The tilted sinusoidal form of the period variation may be considered as an apparent change and may be interpreted in terms of the light-time effect due to the presence of a third body. (c) 2010 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Stars: binaries: eclipsing, Stars: fundamental parameters, Technique: photometry, Stars: individual (RZ Dra)
Kaynak
New Astronomy
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
16
Sayı
1
