The First Photometric Analyses Of Four New Discovered Ew-Type Eclipsing Binaries: GSC 1848-1264, GSC 0804-0118, GSC 0619-0232 And GSC 2936-0478

Abstract

Photometric solutions of four new discovered W UMa-type binaries were carried out for the first time by using the 2003 version of the W-D program. It is discovered that all of the four systems are over-contact binaries. Two binaries, GSC 0804-0118 and GSC 2936-0478, are of A-subtype, while two other binaries, GSC 1848-1264 and GSC 0619-0232, are of W-subtype. From our solutions, the fundamental orbital and physical parameters were determined. For GSC 0619-0232 and GSC 2936-0478, the asymmetries of the light curves (i.e., the O'Connell effect) were explained by the presence of dark spots on the more massive components. Our photometric results reveal that GSC 0619-0232 is an important and interesting system. It is a W-type over-contact binary with a low mass ratio of q = 0.100 and a high over-contact degree of f = 93.4%, which suggests that GSC 0619-0232 may be evolved into a single rapid-rotating star.

Two W-subtype contact binaries: GQ Boo and V1367 Tau

“…It can be found from the three solutions of V1367 Tau in Table 2, the parameters except mass ratio do not differ much from each other. The differences of parameters between the solutions for data of 2016 and Yang et al (2005) are almost smaller than their error ranges. Even when we compare the solutions for data of 2015 and 2016, the differences of most parameters do not exceed 10 per cent, despite the 28 per cent difference between the mass ratios.…”

“…a This solution is the mean value of the last two column solutions, i.e. the solution based on data of 2016 and data from Yang et al (2005). b The primary temperatures were obtained by the method described in Section 4.1. c f = ( star − inner )/( outer − inner ), where star , inner and outer are the modified dimensionless potential of star surface, inner Roche lobe and outer Roche lobe, respectively.…”

“…So the mass ratio 4.40(0.12) may have an uncertainty of 0.5. Besides our observations, the data from Yang et al (2005) were also collected and analysed in the same Figure 3. Upper: the q-search diagram of GQ Boo with the lowest point marked in red.…”

“…The earliest observations of V1367 Tau were released by IBVS (Information Bulletin on Variable Stars) (Menke 2005), and were analysed soon by Yang et al (2005) who obtained its light-curve solution including mass ratio M 2 /M 1 = 2.975(18), temperature ratio T 2 /T 1 = 0.932(4) and inclination i = 66.05 (26). These data are reanalyzed in the following section (Section 4) but the derived mass ratio is larger at M 2 /M 1 = 4.09(31), yet the other parameters do not differ much.…”

First CCD photometry for the contact binary VZ Trianguli

“…After some iterations, the photometric parameters are obtained and listed in Table 3. From this table, the temperature of the secondary is higher than that of the primary up to T = 105 K. This situation occurs in many other A-subtype contact binaries, such as V776 Cas ( T = 25 K; Zoal et al 2005), V802 Aql ( T = 48 K; Yang et al 2008), FG Hya ( T = 88 K; Qian and Yang 2004), GSC 2936-0478 ( T = 115 K; Yang et al 2005), V343 Ori ( T = 162 K; Yang 2009) and YY CrB ( T = 399 K; Gazeas et al 2005). The corresponding theoretical light curve, as a solid line shown in Fig.…”