Aberration of Light               

                                                                                                             Notes
(1) All objects appear displaced towards the direction of the observer's motion (except objects at θ = 0° and θ = 180°.  The greatest
      displacements are on the great circle in the sky, perpendicular to the observer's direction of motion.  On this great circle, Δθ = v/c.
(2) For the orbital motion of the earth v/c = (29.75 km/s)/(299792.458 km/s) = 9.926 ´ 10^-5 = 20.47".  The apex is a point on the ecliptic
      about 90° west of the solar center.
(3) The diurnal apex, associated with the earth's rotation is the east point of the horizon.  The corrections to equatorial coordinates are
      Δα = 0.3198" cos φ cos HA sec δ and Δδ = 0.3198" cos φ sin HA sin δ, where φ is the observer's latitude.
(4) Corrections for both the earth-moon barycenter rotation, and motion about the earth-Jupiter center of mass can be as large as 0.008".
(5) No correction is made for galactic rotation even though this can be as large as ~3', since this correction is virtually constant over many
      millenia.