Abstract

Described is a major new tool for solar research, conceived and built during a time of budget restraint. The observation of magnetic and velocity (circulation) field structure on a synoptic basis and with diffraction-limited resolution is the aim. New optical features include the use of oversize mirrors and windows (to avoid thermal edge effects) and the placement of the coelostat feed outside the vacuum, mainly for economy. The site selected has prevailing winds that clear thermals from these mirrors. Test data in the form of the system MTF and optical transmission, together with examples of full disk magnetograms and photoheliograms, show present performance capability. Measured MTF indicates a response of 0.2 at 1 sec of arc (whereas diffraction-limited response would be ∼0.8). System transmission, including the accompanying spectrograph, is only 2–3% (λ0.44–1.1 μm). Thus, both the optical quality and efficiency are subject to improvement.

© 1976 Optical Society of America

The McMath Solar Telescope of Kitt Peak National Observatory

A. Keith Pierce
Appl. Opt. 3(12) 1337-1346 (1964)

Concepts for the Swedish 50-cm vacuum solar telescope

Göran B. Scharmer, David S. Brown, Lennart Pettersson, and John Rehn
Appl. Opt. 24(16) 2558-2564 (1985)

Auxiliary Optical Systems for the Kitt Peak Telescopes

D. H. Schulte
Appl. Opt. 2(2) 141-151 (1963)

Solar magnetograph employing integrated diode arrays

W. C. Livingston, J. Harvey, C. Slaughter, and D. Trumbo
Appl. Opt. 15(1) 40-52 (1976)

Kitt Peak speckle camera

J. B. Breckinridge, H. A. McAlister, and W. G. Robinson
Appl. Opt. 18(7) 1034-1041 (1979)