Swedish Solar Telescope
Encyclopedia
The Swedish 1-m Solar Telescope (or SST) is a refracting solar telescope
Solar telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum.-Professional solar telescopes:...

 at Roque de los Muchachos Observatory
Roque de los Muchachos Observatory
Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands...

, La Palma
La Palma
La Palma is the most north-westerly of the Canary Islands. La Palma has an area of 706 km2 making it the fifth largest of the seven main Canary Islands...

 in the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...

. It is run by the Institute for Solar Physics
Institute for Solar Physics
The Institute for Solar Physics is a Swedish research institute. It is operated as an independent institute, under the auspices of the Royal Swedish Academy of Sciences, but is associated with Stockholm University through Stockholm Observatory....

 of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...

. The primary element is a single fused silica
Fused quartz
Fused quartz and fused silica are types of glass containing primarily silica in amorphous form. They are manufactured using several different processes...

 lens, making it the second largest optical refracting telescope in use in the world. The 110-cm lens has a clear aperture diameter of 98 cm. The SST is most often used as a Schupmann telescope, thereby correcting the chromatic aberration
Chromatic aberration
In optics, chromatic aberration is a type of distortion in which there is a failure of a lens to focus all colors to the same convergence point. It occurs because lenses have a different refractive index for different wavelengths of light...

s of the singlet primary.

The SST is a vacuum telescope, meaning that it is evacuated internally to avoid disruption of the image from air inside. This is a particular problem with solar telescopes because of the heating from the large amounts of light collected being passed on to any air causing image degradation. As of 2005 it has produced the highest resolution images on the Sun of any telescope, using its adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...

 system.

Currently, the SST is operating with an adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...

 system with a 37-actuator deformable mirror
Deformable mirror
Deformable mirror represents the most convenient tool for wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics...

 from AOPTIX, although upgrades are underway.

The SST superseded the SVST – the Swedish Vacuum Solar Telescope
Swedish Vacuum Solar Telescope
The Swedish Vacuum Solar Telescope was a 47.5 cm solar telescope on La Palma in the Canary Islands. It was removed on 28 August 2000, and has been superseded by the Swedish 1-m Solar Telescope....

 – which was 47.5 cm in diameter.

Instruments

The SST has two modes of operation. One mode is a spectrograph mode, using the TRI-Port Polarimetric Echelle-Littrow (TRIPPEL) spectrograph with a resolution
Spectral resolution
The spectral resolution of a spectrograph, or, more generally, of a frequency spectrum, is a measure of its ability to resolve features in the electromagnetic spectrum...

 of R = 230 000 (corresponding to 1.3 km/s at the solar surface). TRIPPEL is a Littrow spectrograph using a 79 grooves/mm echelle grating
Echelle grating
An echelle grating is a type of diffraction grating which is characterised by a relatively low groove density but is optimized for high diffraction orders. Echelle gratings are, like other types of diffraction grating, used in spectrometers and similar instruments, such as HARPS, and numerous...

 with a blaze angle of 63.43 degrees.

The other mode is an imaging mode, where imaging is split up in a red and a blue beam by a dichroic beamsplitter. The red beam has a tunable filter called CRisp Imaging SpectroPolarimeter (CRISP) which operates from 510 to 860 nm and is able to measure polarization by using liquid crystal modulation combined with a polarizing beamsplitter. The total system uses three 1k × 1k Sarnoff CCDs, two are used for direct observations and the third is used in aiding the MOMFBD image reconstruction method. The blue beam is a setup with a total of 4 MegaPlus II es4020 cameras.

See also

  • List of solar telescopes
  • Dutch Open Telescope
    Dutch Open Telescope
    The Dutch Open Telescope , located on Roque de los Muchachos Observatory, La Palma , is an optical solar telescope with a main mirror of 45 centimeter and can reach an 0.2 arcsec resolution for sustained periods. For further optimization of the images, the DOT uses the image despeckle mechanism...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK