New orbits of wide visual double stars

Based on photographic and CCD observations with the Pulkovo 26-inch refractor, radial velocity measurements with the 1.5-m RTT-150 telescope (TUBITAK National Observatory, Turkey), and highly accurate observations published in the WDS catalog, we have obtained the orbits of ten wide visual double stars by the apparent motion parameter method. The orientation of the orbits in the Galactic coordinate system has been determined. For the outer pair of the multiple star HIP 12780 we have calculated a family of orbits with a minimum period P = 4634 yr. Two equivalent solutions with the same period have been obtained for the stars HIP 50 (P = 949 yr) and HIP 66195 (P = 3237 yr). We have unambiguously determined the orbits of six stars: HIP 12777 (P = 3327 yr), HIP 15058 (P = 420 yr), HIP 33287 (P = 1090 yr), HIP 48429 (P = 1066 yr), HIP 69751 (P = 957 yr), and HIP 73846 (P = 1348 yr). The orbit of HIP 55068 is orientated perpendicularly to the plane of the sky, P >1000 yr. The star HIP 48429 is suspected to have an invisible companion.     

Micrometric measures and orbits of southern visual double stars

525 measures of 213 visual double stars have been made using the 26.5‐inch (67‐cm) Innes telescope in Johannesburg and the Repsold micrometer between 2008.375 and 2008.419, 2010.608 and 2010.652, and 2013.663 and 2013.712. A comparison with known orbits is made. Revised orbits are presented for WDS 01061–4643 (SLR 1), WDS 12415–4858 (HJ 4539), WDS 16253–4909 (COO 197) and WDS 16425–3705 (R 283). (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Astrometric parameters of visual double stars derived from simulated hipparcos measurements

Summary In the course of the reduction ofHipparcos data the astrometric parameter determination of visual binaries is reduced to the parameter determination of single stars. This approach assumes that the off-set of the binary components with respect to the conventional light point directly measured by the Hipparcos telescope are known on the individual scanning circles. The computer algorithms are outlined, preliminary results based on simulated measurements are discussed. Presented by H.-H. Bernstein.     

Photometric observations of visual double stars by the area scanning technique

UBV magnitude differences in visual binaries are presented and their accuracy is discussed. Typical observed image profiles of double stars, including sample profiles of Antares, are shown. This contribution will appear jointly with the earlier one (p. 20) inLowell Obs. Bull., No. 154. The work has been supported by NSF Grant GP-6983.     

On the analytic calculation of visual double star orbits

This article studies the existence of periodic Keplerian orbits for visual double stars whose corresponding apparent orbits are to pass through three selected points. The analytical results provide the basis for a new method of calculating orbits which does not require prior calculation of the areal constant. This method is applied to the binary 04404 N 4313.     

A general catalogue of ephemerides and apparent orbits for visual binaries

Summary Informations on 736 pairs of visual binaries are given in the form of the Tables. The General Catalogue gives ephemerides (t,θ°,ρ″) in 20 years (1984–2003) for each pair with the figures of its apparent elliptical orbit where the positions of secondary component relative to the primary one at different epochs are indicated.The General Catalogue contains four parts: Part one — Source and Grading of Orbit; Part two — Ephemérides and Atlas of Apparent Orbits; Part three — Classifications of Visual Binary Stars; Part four — Indexes of Visual Binary Stars. The principle of calculation and the statistical data are presented in this paper. There are seven statistical tables, giving the elements distribution of true and apparent orbits, grading distribution of orbits, number distribution with different physical property of component of binary star. The number of binary stars in anyone constellation, the number of binary stars brighter than 6^m.5. The number of binary stars nearer than 25 parsec.     

CCD measurements of visual double stars at Calar Alto

342 CCD measurements of relative positions and magnitude differences for 145 visual double stars are presented. Observations were carried out at the 1.23m telescope of the German‐Spanish Astronomical Center at Calar Alto (Spain), all of them in V and R photometric bands.     

Micrometer measurements of visual double stars at Calar Alto

We present 93 micrometer measurements of 55 double stars observed with the 152 cm telescope at the Spanish observatory at Calar Alto (Almeria, Spain).     

Astrometric CCD observations of visual double stars at the Pulkovo Observatory

We present the results of 3489 astrometric observations for 361 visual double stars performed in 2003–2007 with the 26-inch refractor of the Pulkovo Observatory. The angular separations between the components (ρ) and the position angles (θ) are given. The errors in these quantities are, on average, 0″.009 for ρ and 0°.40/ρ for θ, where ρ is the separation in arcseconds.     

The space arrangement of the orbital planes of the visual double stars

A more extended statistical material based on the “Second Catalogue d'Ephémérides de Vitesses radiales relatives” by J. Dommanget and O.Nys (1982) has made possible a new study on the distribution of the orbital poles of visual orbital pairs. It is confirmed that orbital planes do not show any tendancy to be parallel to the galactic plane: at the contrary they show a preference to be perpendicular to it. The most important result is: “Space seems to be divided into elements of the order of 10 to 30 parsecs where visual systems show similar orbital plane orientation”. This confirms a result found in a preceding research (1967) concerning some ten systems surrounding the solar system.     

Confidence intervals for the adjusted parameters in the equations describing the relative motion of an optical visual double star

The problem of assigning formal errors to individual parameters determined in nonlinear least-squares adjustments is briefly reviewed, and the specific case of the equations describing the relative motion of an optical double star is discussed in detail. It is shown how confidence intervals may be computed for the estimated quantities when the equations are expressed in polar form.     

On the formation of double stars

From a calculation of Roche densities in visual binaries, it is concluded that the stars in these systems would be tidally unstable at the time of formation if they were formed with their observed separations (semi-major axes). To avoid this difficulty, it is proposed that the visual binaries are formed by the disintegration of small clusters. Binaries formed this way are shown to have some interesting upper limits to their mass ratios. Comments are also made on the differences between the processe of star and planet formation.     

On the determination of double star orbits

It is proposed to improve the convergence of the determination of the elements of the orbits of visual binaries by using not only first, but second-order derivatives in the development of the appropriate equations of condition. Also, some improvements of the Kowalsky-Seeliger method are suggested which improve the accuracy of the orbit used as first approximation.     

On the orbits of globular clusters of stars in the galaxy

The study of the possible shapes of orbits of globular clusters of stars is closely connected with problems of studying the processes of formation and evolution of stars. The main difficulty in studying the orbits of these objects is the incompleteness of the information about the initial conditions of the motion, in particular the nearly complete absence of observational material on the proper motions of globular clusters. For that reason the study of the motion of these objects by direct dynamic methods has not yet succeeded. In such conditions it is necessary to resort to statistical methods developed by Edmondson and Von Hoerner, which make it possible to draw certain conclusions about the possible shapes of orbits of globular clusters on the basis of the Newtonian point-mass model.The purpose of this paper is to test the results of investigations of other authors against the latest observational data on globular clusters of stars and to develop the method itself further.Translated fromAstrofizika, Vol. 37, No. 4, 1994.