Daniel K. Inouye Solar Telescope
|Named after||Daniel Inouye|
|Part of||Haleakalā Observatory|
|Location(s)||Haleakalā Observatory, Haleakalā, Maui County, Hawaii|
|Organization||National Solar Observatory|
|Altitude||3,084 m (10,118 ft)|
|Wavelength||380 nm (790 THz)–5,000 nm (60 THz)|
|Built||January 2013–November 2021|
|First light||December 2019|
|Telescope style||Gregorian telescope|
|Diameter||4.24 m (13 ft 11 in)|
|Secondary diameter||0.65 m (2 ft 2 in)|
|Illuminated diameter||4 m (13 ft 1 in)|
|Collecting area||12.5 m2 (135 sq ft)|
|Related media on Commons|
The Daniel K. Inouye Solar Telescope (DKIST) is a scientific facility for studies of the sun at Haleakala Observatory on the Hawaiian island of Maui. Known as the Advanced Technology Solar Telescope (ATST) until 2013, it was named after Daniel K. Inouye, a US Senator for Hawaii. It is the world's largest solar telescope, with a 4-meter aperture. The DKIST is funded by National Science Foundation and managed by the National Solar Observatory. It is a collaboration of numerous research institutions. Some test images were released in January 2020. The end of construction and transition into scientific observations was announced in November 2021.
The DKIST can observe the sun in visible to near-infrared wavelengths and has a 4.24-meter primary mirror in an off-axis Gregorian configuration that provides a 4-meter clear, unobstructed aperture. Adaptive optics correct for atmospheric distortions and blurring of the solar image, which enables high-resolution observations of features on the sun as small as 20 km (12 mi). The off-axis, clear aperture design avoids a central obstruction, minimizing scattered light. It also eases operation of adaptive optics and digital image reconstruction such as speckle imaging.
It commenced its first science observations on February 23, 2022, signaling the start of its year-long operations commissioning phase.
The contract to build the telescope was awarded in 2010, with a then-planned completion date of 2017. Physical construction at the DKIST site began in January 2013, and work on the telescope housing was completed in September 2013.
The primary mirror was delivered to the site the night of 1–2 August 2017 and the completed telescope provided images of the sun in unprecedented detail in December 2019. Further instruments, to measure the Sun's magnetic field, were to be added in the first half of 2020. Completion of construction and transition into operational phase with the first scientific observations was announced on November 22, 2021. At the time, the telescope had been over 25 years in the making (including preliminary design etc. not just the building).
Main telescope structure
The 75 mm thick f/2 primary mirror is 4.24 meters in diameter with the outer 12 cm masked, leaving a 4-meter off-axis section of a 12-meter diameter, f/0.67 concave parabola. It was cast from Zerodur by Schott and polished at the Richard F. Caris Mirror Laboratory of the University of Arizona and aluminized by the AMOS mirror coating facility.
The 0.65-meter secondary mirror, a concave ellipsoid with a focal length of 1 meter, was made from silicon carbide and is mounted on a hexapod to compensate for thermal expansion and bending of the telescope structure keeping the mirror in its optimal position.
Adaptive and active optics
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DKIST is expected to have five first-generation instruments.
Visible Broadband Imager (VBI)
The VBI is a diffraction-limited two-channel filtergraph each made of an interference filter and a digital scientific CMOS sensor camera that samples the image of the sun. Each camera features 4k×4k pixels. The interference filters work as a band-pass filter that only transmits a selected wavelength range (i.e. color) of the sunlight. Four different interference filters are available in each channel that are mounted in a motorized fast-change filter wheel.
- 393.327 nm, FWHM: 0.101 nm (Ca II K spectral line, dark-violet)
- 430.520 nm, FWHM: 0.437 nm (G-band, violet)
- 450.287 nm, FWHM: 0.41 nm (blue continuum)
- 486.139 nm, FWHM: 0.0464 nm (H-beta spectral line, turquoise)
- 656.282 nm, FWHM: 0.049 nm (H-alpha spectral line, light-red)
- 668.423 nm, FWHM: 0.442 nm (red continuum)
- 705.839 nm, FWHM: 0.578 nm (Titanium(II) oxide (TiO) spectral line, dark-red)
- 789.186 nm, FWHM: 0.356 nm (Fe XI spectral line)
VBI is fabricated by the National Solar Observatory.
Visible Spectro-Polarimeter (ViSP)
ViSP is fabricated by the High Altitude Observatory.
Visible Tunable Filter (VTF)
VTF is fabricated by the Kiepenheuer-Institut für Sonnenphysik.
Diffraction-Limited Near-InfraRed Spectro-Polarimeter (DL-NIRSP)
Cryogenic Near-InfraRed Spectro-Polarimeter (Cryo-NIRSP)
Cryo-NIRSP is fabricated by Institute for Astronomy (IfA) of the University of Hawaii.
- Corporate Office: Association of Universities for Research in Astronomy
- Funding Agency: National Science Foundation
- Principal Investigator: National Solar Observatory
- Co-Principal Investigators:
- Air Force Research Laboratory
- Bellan Plasma Group, Laboratories of Applied Physics, California Institute of Technology
- Department of Physics and Astronomy, California State University at Northridge
- Colorado Research Associates
- Center for Astrophysics | Harvard & Smithsonian
- Kiepenheuer-Institut für Sonnenphysik, Freiburg, Germany
- Lockheed Martin Solar and Astrophysics Laboratory
- Department of Physics and Astronomy, Michigan State University
- Department of Physics, Montana State University
- NASA Goddard Space Flight Center
- NASA Marshall Space Flight Center
- Plasma Physics Laboratory, Princeton University
- Instrumentation and Space Research Division, Southwest Research Institute
- W.W. Hansen Experimental Physics Laboratory, Stanford University
- University of California Los Angeles
- Center for Astrophysics and Space Sciences, University of California, San Diego
- Center for Astrophysics and Space Astronomy and Joint Institute for Laboratory Astrophysics, University of Colorado at Boulder
- Department of Physics and Astronomy, University of Rochester
- Daniel K. Inouye International Airport
- European Solar Telescope
- List of solar telescopes
- List of largest optical reflecting telescopes
- "Solar Telescope Named for Late Senator Inouye". National Solar Observatory. 16 December 2013. Retrieved 21 October 2015.
- Witze, A. (29 January 2020). "World's most powerful solar telescope is up and running". Nature. doi:10.1038/d41586-020-00224-z. S2CID 213261911.
- Hannah Devlin (29 January 2020). "Telescope captures most detailed pictures yet of the sun". The Guardian.
- Crockett, C. (29 January 2020). "These are the most detailed images of the sun ever taken". Science News. Retrieved 30 January 2020.
- "Great job, team!". Twitter. National Solar Observatory. Retrieved 24 November 2021.
- U.S. NSF’s Daniel K. Inouye Solar Telescope Begins Science Operations Commissioning Phase
- "NSF Selects NSO to Build World's Largest Solar Telescope" (Press release). SpaceRef. 22 January 2010. Retrieved 16 March 2017.
- "Building the DKIST – Image Gallery". dkist.nso.edu. Archived from the original on 13 September 2014. Retrieved 22 August 2015.
- Durand, Pierrot (21 September 2013), "Work on Dome Completed, say Spanish Companies", French Tribune, retrieved 26 September 2013. (Note that the illustration accompanying the article is a 2012 artist’s rendering of the Thirty Meter Telescope calotte dome, and looks nothing like the actual ATST enclosure.)
- "Primary mirror delivered to Daniel K. Inouye Solar Telescope" (Press release). National Science Foundation. 3 August 2017. News Release 17-072.
- Communications, University Relations- (11 December 2015). "UA Completes Primary Mirror for Advanced Solar Telescope". UANews. Retrieved 4 February 2020.
- "DKIST M1 Mirror Successfully Aluminized". NSO - National Solar Observatory. 4 June 2018. Retrieved 4 February 2020.
- "Solar telescope releases first image of a sunspot". phys.org. Retrieved 6 December 2020.
- "DKIST Instruments". NSO - National Solar Observatory. Retrieved 4 February 2020.
- "Collaborating Institutions". dkist.nso.edu. Retrieved 14 May 2014.
Media related to Daniel K. Inouye Solar Telescope at Wikimedia Commons