New BVR photometry and first light curve analysis of the W UMa type eclipsing binary V2240 Cyg
Abstract
New BVR CCD photometric observations of eclipsing binary V2240 Cyg were performed in the summer of 2017 and 2018. Using four observed times of minimum, a new ephemeris of V2240 Cyg is presented. For the first time, the light curves of V2240 Cyg were analyzed. The new observed light curves show that the light maxima are asymmetric. Considering one cool spot on the primary component, the photometric and physical parameters of V2240 Cyg were determined (e.g, Mp = 1.497M⊙ , Ms = 0.167M⊙ , Rp = 1.601R⊙ , Rs = 0.637R⊙ and a = 2.71R⊙). The results of the simulations show that V2240 Cyg is an A-type W UMa binary with a low mass ratio and high overcontact degree f = 59.6 % . The position of both components of V2240 Cyg are shown in the H-R diagram. Collecting all times of minima and using the new ephemeris, the O - C curve was plotted and the orbital period of this binary system was investigated. The O - C curve indicates that the orbital period of V2240 Cyg is decreasing at a rate of dP / dt = - 1.56 ×10-6 d yr-1 , which can be due to mass transfer (M˙ = 2.42 ×10-7M⊙ yr-1) from the primary to the secondary component.
- Publication:
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New Astronomy
- Pub Date:
- August 2020
- DOI:
- 10.1016/j.newast.2020.101391
- Bibcode:
- 2020NewA...7901391O
- Keywords:
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- Techniques: photometric;
- Stars: binaries: eclipsing;
- Stars: individual: (V2240 Cyg)