Physical Parameters of 11,100 Short-period ASAS-SN Eclipsing Contact Binaries

Abstract

Starting from more than 11,200 short-period (less than 0.5 days) EW-type eclipsing binary candidates with the All-Sky Automated Survey for Supernovae V -band light curves, we use the Markov Chain Monte Carlo algorithm and neural networks to obtain the mass ratio ( q ), orbital inclination ( incl ), fill-out factor ( f ), and temperature ratio ( T _s / T _p ). After crossmatching with the Gaia DR3 database, the final sample contains parameters of 2399 A-type and 8712 W-type contact binaries (CBs). We present the distributions of parameters of these 11,111 short-period CBs. The mass ratio ( q ) and fill-out factor ( f ) are found to obey log-normal distributions, and the remaining parameters obey normal distributions. There is a significant period–temperature correlation of these CBs. Additionally, the temperature ratio ( T _s / T _p ) tends to increase as the orbital period decreases for W-type CBs. There is no significant correlation between them for A-type CBs. The mass ratio and fill-out factor ( q − f ) diagram suggest there is no significant correlation between these two parameters. A clear correlation exists between the mass ratio and radius ratio. The radius ratio increases with the mass ratio. Moreover, the deep fill-out CBs tend to fall on the upper boundary of the q − R _s / R _p distribution, while the shallow fill-out CBs fall on the lower boundary.

Keywords

• Contact binary stars
• Eclipsing binary stars
• Fundamental parameters of stars