Ultra-Fast Rotators: Results and Recommendations for Observing Strategies

Lightcurves and amplitudes for two ultra-fast rotating near-Earth asteroids with rotation periods < 20 s observed from Great Shefford Observatory during close approaches in April 2021 are reported: 2021 GQ10 and 2021 HN. The interpretation of lightcurves where exposure length is likely to be a sizable fraction of the rotation period is discussed. Observing strategy recommendations are made to optimize exposure length in near-real time, maximizing the chance of detecting ultra-fast rotation in small objects.