USNOB1.0 14520049820 and ASAS J102556+2049.3: Two W UMa Binaries Close to the Lower Massratio Limit
Abstract
Photometric observations of the W UMa binaries USNOB1.0 14520049820 and ASAS J102556+2049.3 are presented. The results from the light curve solutions are as follows: (i) the component temperatures are T _{1} = 6400 K and T _{2} = 6300 K for USNOB1.0 14520049820 and T _{1} = 6000 K and T _{2} = 5930 K for ASAS J102556+2049; (ii) the photometric mass ratios are well determined because the targets undergo total eclipses; (iii) both mass ratios are close to the lower massratio limit (0.111 and 0.131 correspondingly); (iv) the fillout factors of the two targets are unexpectedly small (0.045 and 0.243, respectively) for their mass ratios. The global parameters of the target components were estimated on the basis of the empirical relationship “periodtotal mass” for low massratio binaries. We established a period decrease for ASAS J102556+2049.3 of dP/dt = 3.39 × 10^{6} day yr^{1}.
 Publication:

The Astronomical Journal
 Pub Date:
 August 2018
 DOI:
 10.3847/15383881/aace5e
 Bibcode:
 2018AJ....156...77K
 Keywords:

 binaries: close;
 binaries: eclipsing;
 stars: fundamental parameters;
 stars: individual: USNOB1.0 1452–0049820 and ASAS J102556+2049.3