PROBABILITIES OF PHYSICAL LINK BETWEEN THE COMPONENTS OF THE SELECTED MULTIPLE SYSTEMS FROM WDS CATALOG

Анотація

Astrometric CCD observations of visual
components of double and multiple stars were performed
using the RI MAO Axial Meridian Circle (AMC) with new
Apogee Alta AI-F8300 CCD camera mounted at the telescope
in 2018. Observations were carried out automatically in drift-
scan mode using a standard R filter. Objects for observational
program were selected from the Washington Double Star
Catalog (WDS). During the 23 nights, 983 observations of 579
double and multiple systems from the WDS catalog were
obtained. Astrometric reductions of the observations showed
high accuracy, with an average error of one position about 0.1"
in right ascension and declination for stars up to 16 mag , which
were observed more than 3 times.
The purpose of our study was to measure the parameters
of the mutual configuration of pairs from the original
images and to draw some conclusions about the physical
connection of the components in the selected systems. The
measurement array that will be sent to the WDS database
includes values of positional angle, angular separation,
stellar magnitude difference, and epoch of the observation.
A detailed analysis of the pairs of stars in the selected 5
systems to clarify their composition and the nature of the
link between them was made. Positional data from the
Hipparcos, Tycho2, UCAC4, Gaia DR2, and Pan-STARRS
(PS1) catalogs were used as sources of additional
information about the investigated stars. The search for
possible invisible stars in the selected systems was
performed using the statistical Wielen method, based on the
analysis of the differences of instantaneous and long-term
averaged proper motions of the stars. The proper motions
of the space Gaia DR2 catalog were considered to be
instantaneous, the long-term averaged proper motions were
used from Tycho-2 and UCAC4 catalogs. Obtained values
of the statistical parameter in some cases indicate a high
probability of existence of invisible close components in
the studied systems. Detailed comments of the results for
each of the selected systems are provided.