Besselian years, encountered in older catalogs, are not often used nowadays to specify the epoch, they used to be used mostly for star positions, but are now becoming obsolete.
Besselian years are not often used nowadays to specify the epoch, they used to be used mostly for star positions. Besselian years were encountered in older catalogs. Besselian years are not often used nowadays to specify the epoch, they are now becoming obsolete. Besselian years are encountered in older catalogs.