PREDNASAJUCI / LECTURER :

Ľubomír Hambálek

(1) Astronomical Institute, Slovak Academy of Sciences,
059 60 Tatranská Lomnica

NAZOV / TITLE :

Photometric mass ratio and other parameters of contact binaries

ABSTRAKT / ABSTRACT :

Light curves (LCs) of close binary stars are relatively simple to describe when considering
a small number of model parameters. However, systems with partial eclipses lead to a more
complicated solution - because the mass ratio (q) of components correlates with the orbital
inclination (i). In today's era of precise spaceborne photometry (e.g. TESS) we can spot
subtle differences between individual LCs that could potentially determine the investigated
system's mass ratio (q), fill-out parameter (f), and inclination (i). We have created a
database of synthetic normalized LCs. These were represented by trigonometric polynomials
to reduce size (several coefficients instead of full phased LC). We employed a grid search
to find closest matching LC with its probable values of q, i, and f parameters. We have
also investigated the effect of unknown third light (l_3) in the system.