Speckle Interferometry of Nearby Multiple Stars. IV. Measurements in 2004 and New Orbits

Abstract

The results of speckle interferometric observations of 104 binary and 6 triple stars performed at the BTA 6 m telescope in 2004 October are presented. Nearby low-mass stars are mostly observed for the program, among which 59 there are new binaries recently discovered by the Hipparcos astrometric satellite. Concurrently with the diffraction-limited position measurements we obtained 154 brightness ratio measurements of binary and multiple star components in different bands of the visible spectrum. New, first-resolved binaries are the symbiotic star CH Cyg with a weak companion at 0.043'' separation and the pair of red dwarfs, GJ 913 = HIP 118212. In addition, we derived the orbital parameters for two interferometric systems: the CN-giant pair HD 210211 = HIP 109281 (P=10.7 yr) and the G2V-K2V binary GJ 9830 = HIP 116259 (P=15.7 yr).Comment: 11 pages, 2 figures, accepted to Astrophysical Bulleti