Star catalog position and proper motion corrections in asteroid astrometry

TL;DR

This paper presents a correction scheme for asteroid astrometry that reduces systematic errors by adjusting star catalog positions and proper motions, leading to more accurate asteroid ephemeris predictions.

Contribution

It introduces a method to correct star catalog errors using PPMXL and 2MASS data, improving asteroid position accuracy and error statistics.

Findings

Enhanced asteroid ephemeris predictions

Reduction of regional systematic errors in asteroid astrometry

Public availability of correction tables for orbit determination

Abstract

We provide a scheme to correct asteroid astrometric observations for star catalog systematic errors due to inaccurate star positions and proper motions. As reference we select the most accurate stars in the PPMXL catalog, i.e., those based on 2MASS astrometry. We compute position and proper motion corrections for 19 of the most used star catalogs. The use of these corrections provides better ephemeris predictions and improves the error statistics of astrometric observations, e.g., by removing most of the regional systematic errors previously seen in Pan-STARRS PS1 asteroid astrometry. The correction table is publicly available at ftp://ssd.jpl.nasa.gov/pub/ssd/debias/debias_2014.tgz and can be freely used in orbit determination algorithms to obtain more reliable asteroid trajectories.