Contact binaries period-luminosity-metallicity

Contact binaries (CBs) possessing period-luminosity (PL) relations could be adopted as distance tracers. The PL relations of CBs are influenced by metallicity abundance and color index, which are connected to both the radius and luminosity of stars.

Here we propose fine relations of the period-luminosity-metallicity-color (PLZC) from the ultraviolet to infrared bands based on current surveys. The accuracy of the distance estimation is 6% and 8%, respectively, depending on the PLZC relations of the CBs in the infrared and optical bands of the collected data. PLZC models are still more accurate than PLC models in determining intrinsic luminosity, notwithstanding their limited improvement.