Extremely large telescope

a twenty-five meter aperture for the twenty-first century

Frank N. Bash, Thomas A. Sebring, Frank B. Ray, Lawrence William Ramsey

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Citations (Scopus)

Abstract

The 10-meter class Hobby-Eberly telescope (HET), now nearing completion, provides technology for optical Arecibo-type telescopes which can be extrapolated to even larger apertures. Utilizing a fixed elevation angle and a spherical segmented primary mirror provides cost effective and pragmatic solutions to mirror mounting and fabrication. Arecibo-type tracking implies a greatly reduced tracking mass and no change to the gravity vector for the primary mirror. Such a telescope can address 70 percent of the available sky and exhibit optical quality easily sufficient for effective spectroscopy and photometry. The extremely large telescope takes advantage of several key engineering approaches demonstrated by the HET project to achieve a cost comparable to similarly-sized radio rather than optical telescopes. These engineering approaches include: bolted pre-manufactured primary mirror truss, factory manufactured geodesic enclosure dome, air bearing rotation of primary mirror, tracker, and dome systems directly on concrete piers, and tracking via a hexapod system. Current estimates put the cost of the ELT at $200 million for a 25-meter aperture utilizing a 33-meter primary mirror array. Construction of the ELT would provide the astronomy community with an optical telescope nearly an order of magnitude larger than even the largest telescopes in operation or under construction today.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherSociety of Photo-Optical Instrumentation Engineers
Pages576-584
Number of pages9
Volume2871
ISBN (Print)0819422681
StatePublished - 1997
EventOptical Telescopes of Today and Tomorrow - Landskrona/Hven, Swed
Duration: May 29 1996May 29 1996

Other

OtherOptical Telescopes of Today and Tomorrow
CityLandskrona/Hven, Swed
Period5/29/965/29/96

Fingerprint

Telescopes
Mirrors
apertures
telescopes
mirrors
Optical telescopes
Domes
Bearings (structural)
domes
costs
Costs
Photometry
Astronomy
Piers
engineering
wharves
Enclosures
Mountings
elevation angle
gas bearings

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Bash, F. N., Sebring, T. A., Ray, F. B., & Ramsey, L. W. (1997). Extremely large telescope: a twenty-five meter aperture for the twenty-first century. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 2871, pp. 576-584). Society of Photo-Optical Instrumentation Engineers.
Bash, Frank N. ; Sebring, Thomas A. ; Ray, Frank B. ; Ramsey, Lawrence William. / Extremely large telescope : a twenty-five meter aperture for the twenty-first century. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 2871 Society of Photo-Optical Instrumentation Engineers, 1997. pp. 576-584
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Bash, FN, Sebring, TA, Ray, FB & Ramsey, LW 1997, Extremely large telescope: a twenty-five meter aperture for the twenty-first century. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 2871, Society of Photo-Optical Instrumentation Engineers, pp. 576-584, Optical Telescopes of Today and Tomorrow, Landskrona/Hven, Swed, 5/29/96.

Extremely large telescope : a twenty-five meter aperture for the twenty-first century. / Bash, Frank N.; Sebring, Thomas A.; Ray, Frank B.; Ramsey, Lawrence William.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 2871 Society of Photo-Optical Instrumentation Engineers, 1997. p. 576-584.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Bash FN, Sebring TA, Ray FB, Ramsey LW. Extremely large telescope: a twenty-five meter aperture for the twenty-first century. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 2871. Society of Photo-Optical Instrumentation Engineers. 1997. p. 576-584