TNG Technical Specifications

• Type: optical/infrared telescope
• Optical design: Ritchey-Chretien F/11 with Active Optics
• Mechanical structure: Alt-Azimuth with derotators on the two Nasmyth foci
• Mirrors (M1, M2, M3): Schott Zerodur
• Primary mirror cell with 78 axial actuators and 24 lateral supports
• Focal length: 38.5 m
• M1 diameter: 3.58 m
• M1 shape: meniscus 24 cm thick
• M1 radius of curvature: 15400 mm, F/2.2
• M2 diameter: 87.5 cm
• M2 radius of curvature: 4417 mm
• M3 major axis: 84 cm
• M3 minor axis: 60 cm
• Field of view: 30 arcmin
• Back Focal Distance: 2900 mm
• Vignetting-free Field: 25 arcmin diameter
• Image Scale: 5.36 arcsec/mm
• Image Quality: 80% Encircled Energy within 0.11 arcsec at 632 nm
• Building: metallic, rotating, height 24 m
• Geographical location: ORM, La Palma, Canary Islands (Spain)
• Astronomical coordinates:
  • Latitude: 28 45'28".3 N
  • Longitude: 17 53'37".9 W
  • Hour Angle: -1h 11m 34.53s
• Geodetic coordinates:
• Latitude: 28 45'14".4 N
• Longitude: 17 53'17".3 W
• Altitude: 2370 m