RR Draconis: An Algol-Type Eclipsing Binary with a Possible Massive Tertiary Companion
H.V. Şenavcı1,2,
A. Čeki3,
E.M. Esmer1,2,
S. Yalçınkaya1,2,
O. Latković3,
E. Bahar1,2,
M. Yılmaz1,2,
Ö. Bastürk1,2,
İ. Özavcı1,2,
O. Yörükoğlu1,2 and
S.O. Selam1,2
1Ankara University, Faculty of Science, Astronomy & Space Sciences Department, Tandoğan, TR-06100, Ankara, Türkiye
2Ankara University Kreiken Observatory, 06837 Ahlatlıbel, Ankara, Türkiye
3Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia
Received: January 28, 2022
ABSTRACT
In this study, we present spectoscopic observations of the
eclipsing binary RR Dra carried out with our recently installed T80
telescope in Ankara University Kreiken Observatory and analyze the
first radial velocity time series of this system. We simultaneously
model TESS light curves along with our radial velocity data to
derive absolute parameters of RR Dra system. Additionally, we
investigate the period variation of the system using all the
available eclipse timings in the literature. In this context, we
discuss two possible explanations for the cyclic nature of the
eclipse timings: i) light-time effect that corresponds to a
high-mass but unseen additional component, ii) magnetic activity of
the cooler component. The secular period increase in eclipse timings
of RR Dra may be a combination of mass transfer and angular momentum
loss, amplified by the presence of circumstellar material.
Key words:
Stars:
individual: RR Dra - Methods: observational - binaries: eclipsing
- Techniques: radial velocity
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