The rapid-response, fully-automated, near-Earth asteroid follow-up program with the SAAO’s 1-m Lesedi telescope

Abstract

We introduce here a program that utilises the robotic observing capabilities of the South African Astronomical Observatory’s 1-meter Lesedi telescope, equipped with the Mookodi instrument to observe newly discovered near-Earth asteroids (NEAs). Observations are automatically scheduled and robotically observed on Lesedi using scripts that continuously monitor new discoveries being reported by the community to the The International Astronomical Union’s Minor Planet Center (IAU MPC), enabling rapid follow-up of newly discovered NEAs, the majority within hours of discovery. The main goal of the program is to study the understudied smaller NEA population, and for that reason this rapid response is essential, as smaller asteroids ( < 100 metres) quickly dim as they move away from Earth, making precise measurements with small-to-medium aperture telescopes challenging. Since the start of this project in February 2023, over 200 NEAs have been observed under this program with approximately 75% of all our observed asteroids having a diameter of less than 100 metres, thereby achieving the primary objective of the program. Although the program primarily targets smaller asteroids, it has also resulted in the observation of 15 NEAs that have subsequently been classified as potentially hazardous asteroids (PHAs). The astrometric data collected during this program have contributed to Minor Planet Electronic Circulars (MPECs) for ∼ 68% of observed targets, thereby contributing to orbital refinement and supporting the official designation of these NEAs — ultimately contributing to planetary defense efforts. • Demonstrates rapid-response follow-up of small near-Earth asteroids using the 1-m Lesedi telescope in South Africa. • Robotic system triggers observations within hours of discovery via NEOCP alerts. • Contributes astrometric data to the Minor Planet Center.