中国科学院云南天文台机构知识库

New photometry for two eclipsing binaries, AX Cas and V1107 Cas, was carried out during the 2014-2015 observing season. With an updated version of the W-D program, photometric solutions were simultaneously derived from BV light curves. Results indicate that AX Cas is a semi-detached binary with a mass ratio of q=0.400(+/- 0.003) and a fill-out factor of f(p)=88.1(+/- 0.5), while V1107 Cas is a contact one with a mass ratio of f=0.667(+/- 0.003) and a degree of contact of f=11.3%(+/- 0.3%). Based on all collected times of light minimum together with newly observed data, we constructed the (O-C) curves for the two systems. From the period analysis, it is found that orbital period variations may evidently appear that show light-time effect. The modulated period and amplitude are P-mod=17.63(+/- 0.17) and A=0.133(+/- 0016) for AX Cas and P-mod=7.23(+/- 0.14)\quad \mathrm{years} and A=0.0023(+/- 0.0002) for V1107 Cas, respectively. From 26 EB/EW binaries with only cyclic variations, we derived the relation between periods and total masses, indicating that mass loss from the system occurs from the semi-detached configuration to the contact case. The cyclic oscillations for 22 sample stars (including AX Cas and V1107 Cas) may be attributed to third bodies. Additional companions could remove angular momentum from the central systems, which may play a key role in the evolutionary process.