Orbit Determination of Close Binary Systems using Lucky Imaging

TL;DR

This paper demonstrates the use of lucky imaging with FastCam to accurately determine the positions of close binary stars, confirming known systems, discovering new companions, and refining orbital parameters.

Contribution

First application of FastCam lucky imaging for visual binary orbit determination, providing high-precision measurements and new orbital data.

Findings

Achieved median positional accuracy of 7 mas in separation and 0.73° in position angle.

Confirmed 18 Hipparcos binaries and discovered new companions.

Revised orbital parameters for four binary systems.

Abstract

We present relative positions of visual binaries observed during 2009 with the FastCam "lucky-imaging" camera at the 1.5-m Carlos Sanchez Telescope (TCS) at the Observatorio del Teide. We obtained 424 CCD observations (averaged in 198 mean relative positions) of 157 binaries with angular separations in the range 0.14-15.40", with a median separation of 0.51". For a given system, each CCD image represents the sum of the best 10-25% images from 1000-5000 short-exposure frames. Derived internal errors were 7 mas in r and 1.2^{\circ} (9 mas) in q. When comparing to systems with very well-known orbits, we find that the rms deviation in r residuals is 23 mas, while the rms deviation in q residuals is 0.73 deg/r. We confirmed 18 Hipparcos binaries and we report new companions to BVD 36 A and J 621 B. For binaries with preliminary orbital parameters, the relative radial velocity was estimated as well. We also present four new revised orbits computed for LDS 873, BU 627 A-BC, BU 628 and HO 197 AB. This work is the first results on visual binaries using the FastCam lucky-imaging camera.