| Term: | Apex |
| Definition: |
The point on the celestial sphere toward which the Sun is apparently moving relative to the local standard of rest. Its position, in the constellation Hercules, is approximately R.A. 18h, Dec. +30°, close to the star Vega. The velocity of this motion is estimated to be about 19.4 km/sec (about 4 AU/year). As a result of this motion, stars seem to be converging toward a point in the opposite direction, the solar antapex. |