Formal uncertainties at G ≃ 15 for sources with a five-parameter astrometric solution. Left: semi-major axis of the error ellipse in position at epoch J2015.5. Middle: standard deviation in parallax. Right: semi-major axis of the error ellipse in proper motion. This and all other full-sky maps in this paper use a Hammer–Aitoff projection in equatorial (ICRS) coordinates with α = δ = 0 at the centre, north up, and α increasing from right to left.