Two recent papers by Lubow, White & Shiao (2021) and White, Lubow & Shiao (2022) have described an algorithm for improving the PS1 astrometry using Gaia EDR3 to remove local coordinate distortions and applying an iterative algorithm for the removal of color-dependent effects from differential chromatic refraction (DCR). The update astrometric information, including improved positions and newly calculated proper motions, are incorporated into the PS1 database.
Database changes
The ObjectThin table's raMean, decMean and associated error columns have been updated, and new columns have been added with proper motions (pmra, pmdec) and errors and with astrometryInfoFlags. See the AstrometryCorrection table if access is required to the positions before the Gaia EDR3 corrections. However, for most users the new values are preferred.
Residual astrometric bias for very blue objects (top) and very red objects (bottom) after Gaia EDR3 correction and application of correction for differential chromatic refraction (from White, Lubow & Shiao 2022). Mean errors are less than 1 mas even for objects with extreme colors.
