A new photometry and period analysis of the Algol-type binary XZ And
Abstract
We present multi-color photometry of the eclipsing binary XZ And, obtained on 2010 October and November with the 60-cm telescope at Xinglong station of National Astronomical Observatories of China. Using the updated W-D program, the photometric elements were deduced from BVR light curves. The results imply that XZ And is a classic Algol-type binary, whose secondary component fills its Roche lobe. The mass ratio and fill-out factor of the primary are q=0.474(±0.003) and f1=68.3(±0.6)%, respectively. Based on photometric and CCD light minimum times, we constructed the O-C curve, which may be described by an upward parabolic line with a quasi-cyclic variation, i.e., light-time orbit. The period and semi-amplitude are Pmod=32.30(±0.06)yr and A=0.d0368(±0.d0008), respectively. This kind of cyclic variation may result from either magnetic activity of the secondary star or light-time effect due to the unseen third body. The long-term period increases at a rate of dP/dt=+5.37(±0.41)×10-7dyr, which may be interpreted by the conservative mass transfer from the secondary component to the primary one. With period increasing, the binary may become wider. Finally, XZ And (i.e., 2.15M⊙+1.02M⊙) will transformed into a binary system consisting of a WD and an unevolved companion.
- Publication:
-
New Astronomy
- Pub Date:
- December 2013
- DOI:
- 10.1016/j.newast.2013.05.001
- Bibcode:
- 2013NewA...25..109Y