The ESO New Technology Telescope


The ESO New Technology Telescope (NTT) is an Alt-Az, 3.58m Richey-Chretien telescope which pioneered the use of active optics. The telescope and its enclosure had a revolutionary design for optimal image quality.

The ESO New Technology Telescope, NTT, was commissioned in 1989, and completely upgraded in 1997 (Big Bang). It has an alt-az mounting, and two Nasmyth focii, which host two instruments. SUSI2 is mounted on Nasmyth A, while since 21 June 2008 EFOSC2 is mounted on Nasmyth B. The pointing error is about 1.5" RMS, but degradation occurs close to zenith and at zenith angle larger than 60 degrees. The pointing is limited to 70deg. zenithal distance, and 3 degrees from zenith.


Call for Ideas for the NTT


The call for ideas for scientific projects with the ESO New Technology Telescope is now closed. For future refence, the call can be found at this link: PDF.

News and Updates

Read the News and Updates page with list of description and addresses of the last modifications of NTT Operations on-line documentation:


Current Instruments

The NTT hosts the following instruments:

Decommissionned Instruments

  • SofI: Son of ISAAC, a large field Infra-Red (1-2.5 micron) spectro-imager;
    See also the Array Information
  • SuSi-2: Superb Seeing Imager - 2, a high-resolution imager;
  • EMMI: ESO Multi-Mode Instrument, a multi-mode spectro-imager, from grism to echelle;
  • SUSI-1;

Content of these Pages

The following items are available on the NTT pages, using the bar on the left.