setâre-ye dotâyi (#)
Fr.: étoile double
An apparently single star which better observational resolution shows it to be a pair of closely lying stars. They may or may not be physically related.
optical double star
setâre-ye dotâyi-ye didgâni
Fr.: étoile double optique
A pair of stars that lie close to each other in the sky by chance, but are not physically associated, in contrast to a true → binary star.
Washington Double Star Catalog
kâtâlog-e setâregân-e dotâyi-ye Washington
Fr.: Washington Double Star Catalogue
A stellar catalog which is the world's principal database of astrometric → double star information. It is maintained by the United States Naval Observatory. The WDS Catalog contains positions (J2000), discoverer designations, epochs, position angles, separations, magnitudes, spectral types, proper motions, and, when available, Durchmusterung numbers and notes for the components of 142552 systems (as of Feb 27 2018).