A Photometric Study of Two Contact Binaries: CRTS J025408.1+265957 and CRTS J012111.1+272933

Abstract

We performed new photometric observations for two contact binaries (i.e., CRTS J025408.1+265957 and CRTS J012111.1+272933), which were observed by the 1.0-m telescope at Xingjiang Astronomical Observatory. From our light curves and several survey data, we derived several sets of photometric solutions. We found that CRTS J025408.1+265957 and CRTS J012111.1+272933 were A- and W-type W UMa, respectively. The results imply that the spot migrates or disappears in two contact binaries, which were identified by chromospheric activity emissions (e.g. Hα emission) from LAMOST spectra. From the O-C curves, the orbital periods of two contact binaries may be increasing, which is interpreted by the mass transfer from the less massive component to the more massive one. With mass transferring, two contact binaries may evolve from the contact configurations to semi-detected ones as predicted by the theory of thermal relaxation oscillation.

Period–Luminosity–Metallicity–Color Relations of Late-type Contact Binaries in the Big Data Era

“…The accuracy of the derived distance is estimated to be 5% (0.11 mag for δ) through the independent test. Moreover, we test the distances of two CBs (CRTS J0254 and J0121) derived from the calibrated PLZC relations with high-precision distances from Ma et al (2022). In this work, the distances of the systems are measured as 1017 and 1247 pc, candidates) are given in columns (3)-( 5), while the corresponding literature is in the seventh column.…”

First Detailed Analysis of a Relatively Deep, Low Mass-ratio Contact Binary: ATO J108.6991+27.8306

“…W Urase Majoris-type (W UMa) binaries are usually contact binary systems in which both components fill the Roche lobe during their main sequence evolutionary phase and share a common envelope (Lucy 1968;Stepien 2006), so that both components have approximate surface temperatures. W UMa binaries, whose component spectral types typically range from F to K, may have magnetic activity, such as starspots (Panchal & Joshi 2021;Poro et al 2021;Ma et al 2022). In addition, W UMa binaries with more massive components but at lower temperatures are defined as W-type W UMa binaries, and the opposite as A-type (Binnendijk 1970).…”