Abstract:
The discovery, characterisation, and monitoring of Near-Earth Objects (NEOs) are critical for
understanding and potentially mitigating the long-term threats to our civilisation from Potential
Hazardous Asteroids (PHAs). Current survey telescopes have a sensitivity of around 20–21
magnitude, which means PHAs, with absolute magnitude H > 22, are typically discovered at
distances of a fraction of an astronomical unit (Jedicke et al. 2016). This has two consequences:
first, the angular speeds of these objects are often tens of arc-seconds per minute in discovery data,
smearing out the faintest objects and making the discovery even more challenging. Second,
uncertainties in preliminary orbits calculated from discovery data coupled with the relatively short
distance from Earth lead to large uncertainties in the sky positions of these objects: ranging from
tens of arc-seconds to a fraction of a degree just half a day after discovery. To confirm such faint
objects and refine their orbits, one needs meter class telescopes with relatively wide fields of view.
