Improved astrometry of (99942) Apophis

► Our original Apophis astrometry suffered from bias. ► The use of the 2MASS astrometric catalog reduces the bias and improves the astrometry of Apophis. ► Over 430 observations of Apophis now show an RMS error of only 0.12 arcsec. ► Telescope tracking inconsistency is now recognized as a source of additional error.