Digital Tracking Observations Can Discover Asteroids Ten Times Fainter than Conventional Searches

TL;DR

Digital tracking significantly enhances the sensitivity of telescopic asteroid searches, enabling detection of objects ten times fainter than traditional methods, thus opening new possibilities for discovering faint asteroids across various populations.

Contribution

This paper develops and validates a digital tracking methodology for large-format CCD imagers, greatly improving the detection capabilities for faint main belt and near-Earth asteroids.

Findings

Detected 156 new asteroids and 59 known objects in a single field

Achieved tenfold sensitivity improvement over conventional searches

Validated methodology with ground-based observations using the WIYN telescope

Abstract

We describe digital tracking, a method for asteroid searches that greatly increases the sensitivity of a telescope to faint unknown asteroids. It has been previously used to detect faint Kuiper Belt objects using the Hubble Space Telescope and large ground-based instruments, and to find a small, fast-moving asteroid during a close approach to Earth. We complement this earlier work by developing digital tracking methodology for detecting asteroids using large-format CCD imagers. We demonstrate that the technique enables the ground-based detection of large numbers of new faint asteroids. Our methodology resolves or circumvents all major obstacles to the large-scale application of digital tracking for finding main belt and near-Earth asteroids. We find that for both asteroid populations, digital tracking can deliver a factor of ten improvement over conventional searches. Digital tracking has long been standard practice for deep Kuiper Belt surveys, but even there our methodology enables deeper integrations than have yet been attempted. Our search for main belt asteroids using a one-degree imager on the 0.9m WIYN telescope on Kitt Peak validates our methodology, delivers sensitivity to asteroids in a regime previously probed only with 4-meter and larger instruments, and leads to the detection of 156 previously unknown asteroids and 59 known objects in a single field. Digital tracking has the potential to revolutionize searches for faint moving objects ranging from the Kuiper Belt through main belt and near-Earth asteroids, and perhaps even anthropogenic space debris in low Earth orbit.