instrument is available for reference stars in the magnitude range 3.5 to 9.8 with
degraded performance, and at design performance for fainter reference stars
(down to ~16).
guide star adaptive optics systems at LBT: FLAO commissioning and science
operations status, Esposito, et al., SPIE (2012)
– Field Guide to Adaptive Optics,
Tyson & Frazier, SPIE Press (2012)
– Adaptive Optics and its Applications, C. Max, (click here)