Richard B. Dunn Solar Telescope
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Alternative names | Vacuum Tower Telescope at Sacramento Peak, Richard B. Dunn Solar Telescope |
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Named after | Richard B. Dunn |
Part of | Sunspot Solar Observatory |
Location(s) | New Mexico |
Coordinates | 32°47′14″N 105°49′14″W / 32.78728°N 105.8205°W |
Organization | New Mexico State University |
Wavelength | 310 nm (970 THz)–1,000 nm (300 THz) |
Telescope style | optical telescope solar telescope research structure |
Diameter | 76 cm (2 ft 6 in) |
Angular resolution | 0.1 milliarcsecond, 0.33 milliarcsecond |
Collecting area | 0.456 m2 (4.91 sq ft) |
Focal length | 54.86 m (180 ft 0 in) |
Website | sunspot |
Related media on Commons | |
The Dunn Solar Telescope also known as the Richard B. Dunn Solar Telescope
Telescope
The Dunn Solar Telescope specializes in solar high-resolution imaging and spectroscopy. These observations allow solar astronomers worldwide to obtain a better understanding of the Sun. The telescope was inaugurated as the world's premier high spatial resolution optical solar telescope in 1969. With a horizontal rotating 40-foot-wide observing platform, such that instruments do not have to be mounted on the telescope itself, the Dunn Solar Telescope continues to offer a versatile, user-friendly setup. It has two high-order adaptive optics benches to compensate for blurring by Earth's atmosphere. Scientists and engineers use the Dunn to investigate a range of solar activities, often in concert with satellites or rocket launches, and to develop new technologies for the 4-meter Daniel K. Inouye Solar Telescope.
Like an iceberg, only a part of the telescope's bulk is visible above ground. The optical path starts at a heliostat on top of a 136-foot-tall (41 m) tower and continues 193 feet (59 m) more underground to the primary mirror.[3] The lowest excavated point (the bottom of the sump) is 228 feet (69 m) below ground. It then returns to one of six quartz optical windows in the floor of an optical laboratory at ground level. The whole building from top to bottom is a single instrument. The telescope's entire optical system – from the top of the Tower to the base of its underground portion, plus the 40-foot diameter observing room floor – is suspended from the top of the Tower by a mercury float bearing. The bearing, in turn, is hung on three bolts, each only 76 millimeters (3.0 in) in diameter. The entire optical and mechanical structure of the telescope is longer than a football field and weighs over 250 tons. The optics are evacuated to eliminate distortion due to convection in the telescope that would otherwise be caused by the great heat produced by focusing the light of the sun. A unique feature of the telescope is its approach to image derotation: the entire 100-metre-long (330 ft) telescope and 40-foot-diameter (12 m) optics lab, 250 tons total, rotates suspended from a mercury float bearing at the top of the tower.
Despite the size and weight, much of the telescope can be controlled and monitored from a single control room, off to one side of the main instrument observing table.
Instruments
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The Dunn Solar Telescope has a rotating optical bench, which can be configured to multiple observing setups, depending on the requirements of the science under study. The four most widely used instruments, often used together in one complex observing set up are:
- Facility InfraRed Spectropolarimeter (FIRS)
The Facility IR Spectropolarimeter is a multi-slit
- Spectro-POlarimeter for INfrared and Optical Regions (SPINOR)
The Spectro-POlarimeter for INfrared and Optical Regions performs achromatic lens Stokes polarimetry across several visible and infrared spectral regions. Completed in 2005, it was designed to act as 'experimental oriented' instrument, built with a flexibility to allow for the combination of any many spectral lines, "limited only by practical considerations (e.g., the number of detectors available, space on the optical bench, etc.)" [5]
- Interferometric BI-dimensional Spectro-polarimeter (IBIS)
The Interferometric BIdimensional Spectropolarimeter (IBIS) -is a dual interferometer, imaging, spectro-polarimeter. It uses a series of precise piezo-electric tuning to rapidly scan selected spectral lines between 550 and 860 nm range. This creates a time series of high-fidelity imaging, spectroscopy, and polarimetry of the Sun. It has a large circular field-of-view combined with high spectral (R ≥ 200 000), spatial ≃ 0.2″), and temporal resolution (several frames per second) [6]
- Rapid Oscillations in the Solar Atmosphere (ROSA)
The Rapid Oscillations in the Solar Atmosphere (ROSA) instrument is a single-controlled system of 6 imaging fast-readout CCD cameras. The full chip on each camera can be read out 30 frames per second, and all the cameras are triggered from one control system. As such, it provides the ability to image multiple layers of the photosphere and chromosphere simultaneously. At its installation in 2010 it generated up to 12 TB of data per day [7] making it one of the largest data sets in ground-based solar astronomy at the time.
In addition, some older instruments are available, although these are now rarely used.
- Universal Birefringent Filter (UBF)
- Advanced Stokes Polarimeter (ASP)
- Diffraction-Limited Spectro-Polarimeter (DLSP)
Scientific discoveries, technologies, and scientists
This section needs expansion with: examples and additional citations. You can help by adding to it. (July 2018) |
Inferring telescope polarization properties through spectral lines without linear polarization.[8] Derks, A., Beck, C., Martínez Pillet, V., 2018. Astronomy and Astrophysics volume 615, A22 (2018)
Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging.[9] Underwood, T.A., Voelz, D., Schmider, F.-X., Jackiewicz, J., Dejonghe, J., Bresson, Y., Hull, R., Goncalves, I., Gualme, Pa., Morand, F., Preis O., SPIE Optical Engineering 10401Y (2017)
Solar coronal magnetic fields derived using seismology techniques applied to omnipresent sunspot waves.[10] Jess et al., 2016. Cover Article of Nature Physics, Volume 12 Issue 2, February 2016
Solar Multi-Conjugate Adaptive Optics at the Dunn Solar Telescope[11] Rimmele, T., Hegwer, S., Richards, K., Woeger, F.. , 2008, Multi-Conjugate Adaptive Optics.
Speckle interferometry with adaptive optics corrected solar data[12] Wöger, F., von der Lühe, O., Reardon, K., 2008, Speckle Interferometry.
History
A design for a Solar
More than half the entire building is underground – the tower extends 136 feet above ground and 220 feet below ground. A vertical vacuum tube is enclosed within the concrete tower with 3-foot-thick walls. An entrance window at the top of the tower, and two mirrors, reflect sunlight down the vacuum tube where it is reflected off the 64 inches primary mirror. The primary mirror acts to focus the light, and sends it back up to ground level, where it exits the vacuum tube on the optical benches inside the building. The interior vacuum tube of more than 250 tons is suspended by a bearing that contains 10 tons of mercury. This bearing allowing the entire 250 ton vacuum tube to be rotated, compensating for the apparent rotation of the image as the Sun rises into the sky.
The tower telescope was originally dedicated on October 15, 1969, and renamed in 1998[15] after Richard B. Dunn.[16] A plaque at the facility reads: "Named in honor of one of solar astronomy's most creative instrument builders, this vacuum tower telescope is the masterpiece of Richard B. Dunn's long scientific career at
See also
References
- ^ Raftery, Claire (2018-04-30). "Dunn Solar Telescope". NSO - National Solar Observatory. Retrieved 2023-09-12.
- ^ Udall, Heinrich, Pearce Announce $1.2 Million to Upgrade Dunn Solar Telescope in Sunspot, NM, Transition Operation to NMSU Consortium, 2016-09-22
- ^ "Dunn Solar Telescope Instrumentation". Richard B. Dunn Solar Telescope website. Retrieved 2013-09-26.
- ^ FISR User Manial (PDF), 2010-01-04
- S2CID 509001
- ^ ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System (PDF), 2010-01-01
- S2CID 54512800
- S2CID 125319186
- S2CID 118433180
- Bibcode:2008amos.confE..18R
- ^ Richard B. Dunn (1927 - 2005)
- ^ Dunn, Richard B. 1969. Sacramento Peak's New Solar Telescope. Sky and Telescope. Vol. 38, No. 6.
- ^ World's Premier Solar Telescope Named After its Creator, Dr. Richard B. Dunn, 1998-09-21
- ^ Rutten, Robert J. (1999), "The Dutch Open Telescope: History, Status, Prospects" (PDF), in T. Rimmele; K. Balasubramiam; R. Radick (eds.), High Resolution Solar Physics: Theory, Observations, and Techniques
External links
- Dunn Solar Telescope website
- Virtual tour of the DST