Discover

'Thirty Meter Telescope'

Organizations	Caltech, the University of California, and ACURA
Logo
Wavelength regime	Infrared, Visible light (0.31-28 µm)
Location	Still to be determined; sites considered are in Mexico, Chile, and Hawaii.
Completion	2014
Webpage	http://www.tmt.org/
Physical Characteristics
Telescope Style	Ritchey-Chrétien
Diameter	30 m
Collecting Area	~650 m2
Focal Length	450 m
Primary Mirror	Consists of 492 hexagonal segments each about ~1.4 m in diameter

The 'Thirty meter telescope (TMT)' (formerly called the 'California Extremely Large Telescope (CELT)') is a future large segmented-mirror optical and infrared extremely large telescope, proposed and run by a consortium made up by Caltech, the University of California, and ACURA. Completion is scheduled for November 2014.
The 'TMT' is an extremely large telescope design first proposed in the 1990s by a consortium of Californian Universities under the name ''California Extremely Large Telescope'', but this name was changed when additional institutions from outside California joined the project. The design is for a segmented 30m diameter astronomical telescope.
The optical design for the TMT is a Ritchey-Chretien two mirror system. This rather naturally provides a large, 20 arc minute field of view (15 arc minute unvignetted) with under 0.5 arcsecond images (100% enclosed energy). This focus is free of coma and only suffers from astigmatism, which grows quadratically with field angle. The primary will be 30 m in diameter, and for compactness, the primary f-ratio will be f/1.5. The final focus will be f/15, delivering a final focus with about 2 mm/ arc second as its plate scale. Such a giant telescope produces very large seeing-limited images, a challenge for the design of seeing-limited scientific instruments. The 20 arcminute field is 2.6 m in diameter.
The telescope will have a simplified design in order to minimize the cost. Thus there will be no prime focus, nor a Cassegrain focus. All scientific work is expected to be done at the bent Cassegrain and Nasmyth foci.

Contents

See also

External links

See also

★ List of optical telescopes

★ Giant Magellan Telescope

★ Overwhelmingly Large Telescope

External links

★ Project web site

★ Caltech web site

★ Old CELT website

★ New Lick Observatory TMT site