J/AZh/98/239 Orbits of Four Visual Binaries (Romanenko+, 2021) ================================================================================ Improving the Orbits of Four Visual Binaries Using Gaia DR2 Data and Observations with the 26-inch Refractor of Pulkovo Observatory. Romanenko L.G., Izmailov I.S. =2021AZh....98..239R (SIMBAD/NED BibCode) =2021ARep...65..209R ================================================================================ ADC_Keywords: Stars, double and multiple ; Positional data Keywords: visual double stars - positional data Description: We use a modified method of the apparent motion parameters (AMP), in which the initial data from the Gaia DR2 catalog are not only high-precision coordinates, parallaxes, and radial velocities of the components of the studied wide binary stars, but are also their proper motions. The coincidence of the AMP orbits obtained both from the Gaia DR2 data and from the Pulkovo series from 1960-2019 leads to an orbit that is unambiguous in terms of an ascending node. The results for improving the orbits of such visual binaries of the Pulkovo research program as ADS 246, 2757, 10386, and 12169 are presented. Orbits (with periods of 1226, 1075, 4500, and 4900 years), orbital orientation parameters in the Galaxy coordinate frame, and the masses of these systems are obtained (0.59+/-0.05, 1.7+/-0.3, 1.7+/-0.4, and 2.25+/-0.5M_{sun}_). It is shown that dense homogeneous series of ground-based observations, such as CCD observations with the 26-inch refractor of the Pulkovo Observatory, do not lose their relevance, serve as the basis for identifying the best solution based on both Gaia data and our own observations, and should be continued. It was also shown that the Thiele-Innes method is not suitable for determining the orbits of binary stars with a separation of more than 100AU. Objects: --------------------------------------------------- RA (2000) DE Designation(s) --------------------------------------------------- 00 18 22.88 +44 01 22.6 ADS 246 = BD+43 44 03 47 02.11 +41 25 38.1 ADS 2757 = BD+41 750 17 10 10.51 +54 29 39.9 ADS 10386 = BD+54 1861 19 12 05.03 +49 51 20.7 ADS 12169 = BD+49 2959 --------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 61 385 Positional data of separate nights table2.dat 61 59 Yearly average positions -------------------------------------------------------------------------------- See also: I/345 : Gaia DR2 (Gaia Collaboration, 2018) Byte-by-byte Description of file: table1.dat table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 I5 --- ADS ADS number 7- 12 F6.3 yr Epoch Epoch of observation (Epoch-2000) 14- 16 I3 --- N Number of CCD frames 18- 24 F7.4 deg theta Position Angle based on the equinox for the epoch of observation (1) 26- 33 F8.4 arcsec rho Separation 35- 40 F6.4 deg e_theta Standard deviation in theta 42- 47 F6.4 arcsec e_rho Standard deviation in rho 49- 54 F6.4 arcsec e_theta2 Standard deviation of one CCD image in theta 56- 61 F6.4 arcsec e_rho2 Standard deviation of one CCD image in rho -------------------------------------------------------------------------------- Note (1): The position angle has not been corrected for precession, and is thus based on the equinox for the epoch of observation. -------------------------------------------------------------------------------- Acknowledgements: Igor Izmailov, i_izmailov(at)mail.ru ================================================================================ (End) Igor Izmailov [Pulkovo Obs.], Patricia Vannier [CDS] 19-Apr-2021