Direction of movement sun with respect to the NGP
Backer and Sramek 1999
observed that relative to more distant radio sources, the galactic center
Sgr A*
had a heliocentric proper motion
of about -6 milliarcseconds per year in galactic longitude.
Reid et al. 1999
reported a similar result.
Looking from NGP to SGP,
galactic longitude
increases counterclockwise, a decrease in longitude is a clockwise motion, and the Sun revolves clockwise around the galactic center.