Mayall 4m Telescope

The Mayall 4m Telescope (aka KPNO 4m, Kitt Peak 4m, or Nicholas U. Mayall Telescope) is a 4-meter reflector telescope at Kitt Peak National Observatory (KPNO) in Arizona. It was built in 1973, at which time it was the second largest telescope in the world after Hale Telescope and like the Hale, it has an equatorial mount. It was the model for the 1976 Víctor M. Blanco Telescope at Cerro Tololo Inter-American Observatory (CTIO), Chile. As of 2023, the Mayall 4m is dedicated to an ongoing survey using the Dark Energy Spectroscopic Instrument (DESI) multi-object spectrograph, with early release announced in June 2023.