A photometric study of two contact binaries: CRTS J025408.1+265957 and CRTS J012111.1+272933

S. Ma, J. Z. Liu, Y. Zhang, Q. S. Hu, G. L. Lv

Published 2022-07-13Version 1

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 Aand 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. H{\alpha} 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.