CCD Measurements of Double and Multiple Stars at ASV and NAO Rozhen in 2017 and 2018

Abstract

Abstract We give the results of CCD observations for 789 double or multiple stars obtained during 2017 and 2018. These observations were carried out at both the Serbian Astronomical Station on the mountain of Vidojevica (ASV) and the Bulgarian National Astronomical Observatory at Rozhen (NAOR). They were performed using three telescopes, the 1.4 and 0.6 m telescopes at ASV, and the 2 m telescope at NAOR. The total of 1196 measurements (position angle and angular separation) for the 939 pairs is presented. Out of this number, 55 pairs have calculated orbital or linear elements and for them the residuals are given. Some pairs have measurements for several epochs. Measured angular separations are in the interval from 1.″51 to 208.″81, with a median separation of 4.″16. Two new pairs and linear elements for three pairs, which are calculated for the first time, are also presented.