Light curve and period study of V Trianguli

Abstract

New BVR light curves and times of minimum light for the short period β Lyrae system V Tri were analyzed to derive the physical parameters of the system. The light curves were obtained at Ankara University Observatory and at the TÜBİTAK National Observatory during 5 nights in 2001 and 2002. A new ephemeris is determined for the times of primary minimum. The analysis of the light curves is made using the Wilson-Devinney 2003 code. The present solution reveals that V Tri is a near-contact system with a mass ratio near 0.5. The absolute radii and masses estimated for the components, based on our photometric solution, are R1 = 1.94 R , R2 = 1.44 R , M1 = 2.68 M , M2 = 1.36 M , respectively, for the primary and secondary components. The period variation of the system can be attributed to the light-time effect. With the assumption of a coplanar orbit of the third body its revealed mass is m 3 = 0.17 M .

Photometric and Spectroscopic Observations of the Algol Type Binary V Triangle

“…All the observations have been transferred into phases by using the newly derived quadratic ephemeris as shown in Figure 1. Unlike that obtained by Jordan (1929), the obviously symmetry of light curve is shown at the maximum but no so-called O'Connell effect on light curves as pointed out by Gürol et al (2006). Agree with the primal classified type (Leavitt & Pickering 1913), the general feature of the light curves is belongs to that of Algol-type binary system with equal light maximum and minimum.…”

“…was published by Gürol et al (2006) from photoelectric and CCD measurements. Using the classical O − C method, we calculated the revised linear and quadratic The O − C linear and quadratic residuals for the times of light minimum were calculated as listed in the sixth and seventh column of Table 4, respectively.…”

“…Table 4 continued Table 4 continued A third body may be as the cause of period change in Algol-type systems (Hoffman et al 2006). The period variation of the V Tri have been attributed to the light-time effect by Gürol et al (2006), they assumed a third body cause the sinusoidal variation in the orbital period of the eclipsing binary star system. Including our 6 CCD light minima, we collected all available light minima from literatures to find out how the change of orbital period will be in the last few decades.…”

“…Giuricin et al (1983) marked V Tri as an "a" systems which means a non-contact configuration, but some authors were inclined to a near-contact configuration (Budding (1984); Shaw (1994); Gray et al (1994)). In recent study, Gürol et al (2006) derived the physical parameters of the system from BV R light curves using the Mode 2 (detached configuration) and Mode 5 (semi-detached configuration with the the secondary component accurately filling its limiting lobe) of Wilson-Devinney (WD) 2003 code.…”

“…The peculiar period behavior of this systems were discussed by Gray et al (1994) based on light minimum timings from 1902 to 1992. Furthermore, Gürol et al (2006) analyzed the period of V Tri and attributed the O − C (observed minus calculated period) variations of all minima to the light-time effect caused by a third body.…”