McMath–Pierce solar telescope

The inside of the slanted shaft

The telescope is a triple instrument. In addition to the primary 1.61 m mirror fed by the 2.03 m heliostat, there are a pair of telescopes fed by 0.81 m heliostats mounted beside the main heliostat. These two instruments have 1.07 m and 0.91 m primary mirrors.[6]

The top of the tower.

Results of adaptive optics

The telescope uses the heliostat at the top of its main tower to direct the Sun's light down a long shaft to the primary mirrors. The distinctive diagonal shaft continues underground, where the telescope's primary mirror is located. The theoretical resolution of the main telescope is 0.07 arcsec, although this is never reached because atmospheric distortions degrade the image quality severely. The image scale is 2.50 arcsec/mm at the image plane. Since 2002 the National Solar Observatory staff have developed an adaptive optics system designed for the unique needs of solar observatories that dramatically improve the resolution of science images.[7]

The secondary telescopes are called East and West. They are completely independent of the main telescope. These two auxiliary telescopes each have a 0.91-meter heliostat located beside the main heliostat. These auxiliary telescopes have a slightly shorter focal length and f-numbers of 50 and 44. The resolution of the auxiliary telescopes is 5.11 arcsec/mm and 5.75 arcsec/mm.[6]

The enclosure of the telescope was designed and engineered by the Chicago office of Skidmore, Owings and Merrill.[8]

At the dedication in 1962, Dr. Waterman read a letter[9] from President John F Kennedy starting with:

The great new solar telescope at the Kitt Peak National Observatory in Arizona is a source of pride to the nation. The largest instrument for solar research in the world, it presents American astronomers with a unique tool for investigating the nearest of the stars, our sun. This project is of exceptional interest to all our citizens...

The third mirror of the main telescope which sends the light down into the observing room can be moved above three different positions. Two of these have a vacuum spectrograph beneath them, one of 18 meter deep and the other 4 meter deep with lower resolution but higher light throughput. These two spectrographs are able to rotate to compensate for the rotation of the image caused by the use of a heliostat. The third position can only be equipped with a static optical table with no image rotation correction and is therefore rarely used.

A notification of 1992 rededication of the telescope.

The auxiliary telescopes can only be used for imaging on static optical tables and do not provide image rotation correction.

In 2016, the National Science Foundation (NSF) announced that it would be divesting from the McMath-Pierce solar observatory. The operator, known as National Solar Observatory, began accepting proposals from new potential operators. A concept for retrofitting by the Kitt Peak visitor center manager was first provided to the NSF for consideration in July 2017. That concept was ultimately developed into a funding proposal to the NSF, submitted again in May 2018. This proposal was awarded in September 2018 by the NSF to the Association of Universities for Research in Astronomy, the organization that operates Kitt Peak National Observatory on behalf of the NSF.[10][11]

• List of solar telescopes
• Lists of telescopes
• List of largest optical reflecting telescopes
• Daniel K. Inouye Solar Telescope (Major new solar telescope project of the early 21st century)

• Media related to McMath–Pierce solar telescope at Wikimedia Commons
• Kitt Peak virtual tour: McMath–Pierce Solar Telescope
• "McMath Solar Telescope of the Kitt Peak National Observatory", A. K. Pierce, Applied Optics, 3, 1337–1346, 1964.
• A History of the McMath–Pierce
• Schematic diagram of the McMath–Pierce telescope
• Adaptive optics at the McMath–Pierce telescope