Photometric study and absolute parameters estimation of six totally eclipsing contact binaries

TL;DR

This study presents high-precision observations and analysis of six totally eclipsing contact binaries, revealing their types, period variations, and estimating their absolute parameters using Gaia data, contributing to understanding their evolution.

Contribution

It provides the first detailed analysis of six totally eclipsing contact binaries, including their classification, period changes, and absolute parameters estimation using Gaia distances.

Findings

Only one target is an A-type contact binary.

Two binaries show secular period increase.

Three binaries exhibit long-term period decrease.

Abstract

High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033 Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that Gaia distance can be applied to estimate absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated by using their Gaia distances. The evolutionary status of contact binaries was studied, we found that the A- and W- subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It is discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.