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

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

Speckle interferometry of nearby multiple stars. II.

This paper is a continuation of diffraction-limited speckle interferometry of binary and multiple stars carried out at the 6-m telescope of the Special Astrophysical Observatory in Zelenchuk. The program has concentrated on nearby ($\pi>10$ mas) close binaries discovered or measured during the Hipparcos mission. Here, we present 132 measurements of relative positions and magnitude differences for 99 pairs and 8 measurements for 6 triple systems. 54 entries in the paper are new Hipparcos binaries. New triple systems with late-type dwarf components, discovered in the course of observations, are HIP 8533 and HIP 25354

Binary star speckle measurements during 1992-1997 from the SAO 6-m and 1-m telescopes in Zelenchuk

We present the results of speckle interferometric measurements of binary stars made with the television photon-counting camera at the 6-m Big Azimuthal Telescope (BTA) and 1-m telescope of the Special Astrophysical Observatory (SAO) between August 1992 and May 1997. The data contain 89 observations of 62 star systems on the large telescope and 21 on the smaller one. For the 6-m aperture 18 systems remained unresolved. The measured angular separation ranged from 39 mas, two times above the BTA diffraction limit, to 1593 mas

Orbits of new Hipparcos binaries. I

We present first orbits for 6 new Hipparcos binaries. The orbits were determined from speckle interferometric measurements collected mainly at the 6 m BTA telescope of the Special Astrophysical Observatory in Zelenchuk. Three of the systems, HIP 11352, HIP 14075 and HIP 14230, have late G- or early K-type components, while HIP 14669 = GJ 125, HIP 106972 = GJ 4210 and HIP 111685 = GJ 4287 have M-type components. The periods of the orbits are in the range of 6-28 years. Mass sums and their errors are derived for the systems. The Hipparcos parallax error is the dominating error source of the mass determination.

Orbits of new Hipparcos binaries. II

We continue the presentation of new orbits for Hipparcos binaries determined from regular speckle interferometric observations. Most of the data were collected in the period between 1998.77 and 2004.82 using the 6 m BTA telescope of the Special Astrophysical Observatory in Zelenchuk. New orbits are presented for six pairs: HIP 4809, HIP 4849, HIP 5531, HIP 19206, HIP 105947, and HIP 114922. One of the pairs, HIP 114922, has M dwarf components orbiting with a period of 19.72 yr. Two binaries, HIP 4809 and HIP 5531, have luminosity class IV components. The periods of the orbits range from 7.30 yr to 28.99 yr. All of the orbits can be considered definitive; however, the total mass error for the systems remains high, mainly due to Hipparcos parallax error