The triple system KR Com

TL;DR

This study combines photometry, interferometry, and period analysis to comprehensively characterize the triple system KR Com, revealing its orbital parameters, component properties, and distance with novel integration of minima timings.

Contribution

It introduces a new approach by combining minima timings with visual orbit data to analyze the period variation and orbital orientation of the triple system KR Com.

Findings

Distant third component orbits on an 11-year high-eccentricity orbit.

Component temperatures are 5549 K and 6072 K for primary and secondary.

Distance to the system is determined as approximately 64 parsecs.

Abstract

Aims: We present the detailed analysis of triple system KR Com with different observational techniques - photometry, interferometry, and period variation. Methods: The use of BVR photometry of the close-contact binary KR Com, which is the primary component of a triple system, helps us to better describe the properties of the components. The interferometric data obtained during the last 30 years sufficiently determine the visual orbit, but the use of minima timings of KR Com for the study of period variation together with the visual orbit is a novel approach in this system. Results: Basic physical parameters resulting from the light curve analysis agree well with the previous results from spectroscopy. The temperatures for the primary and secondary component resulted in 5549 and 6072 K, respectively, and the amount of the third light in all filters is about 1/3 of the total luminosity. The distant third component revolves around the common barycenter on 11 yr orbit with a very high eccentricity (0.934) and this movement is also detectable via the period variation, which is clearly visible in the O-C diagram of times of minima observations. The use of minima times for the combined analysis helps us to independently determine the distance to the system (64.02 +/- 9.42 pc) and also to confirm the orientation of the orbit in space. Conclusions: New minima observations and also spectroscopy would be very profitable, especially during the next periastron passage in the year 2017.