The Nordic Optical Telescope (NOT) is an astronomical

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

located at Roque de los Muchachos Observatory, La Palma in the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

. The telescope saw first light in 1988, and was officially inaugurated during September 1989. Regular observing started in 1990. It is funded by

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark ...

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

, and (since 1997)

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

. Access is provided directly to astronomers of the funding countries, and of all nationalities through international time allocation committees. The main mirror has a diameter of . The optical forming was done at the optical laboratory at the Tuorla Observatory, on mirror blanks made of Zerodur at Schott Glaswerke in Mainz, Germany. While the NOT was designed as a passive telescope, with the mirror sufficiently thick to keep its shape even without an active feedback loop, its mirror was designed to be suspended on a pneumatic support system. The designers had planned that this and the flexibility of the mirror would allow for the implementation of a so-called active optics system, a feature that was then under development for

ESO The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ...

New Technology Telescope The New Technology Telescope or NTT is a 3.58-metre Ritchey–Chrétien telescope operated by the European Southern Observatory. It began operations in 1989. It is located in Chile at the La Silla Observatory and was an early pioneer in the use of ...

. In 1992, such an active optics system was installed at the NOT.

Instrumentation

The NOT operates three instruments that can be mounted -only one at a time- under the Cassegrain focus:
ALFOSC
a

CCD camera A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

and

spectrograph An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...

. This is a versatile instrument that gets most time in the focus. It includes a polarimetry module that allows it to be used for polarimetry and spectropolarimetry.
NOTCam
a

near infrared camera NIRCam (Near-InfraRed Camera) is an instrument aboard the James Webb Space Telescope. It has two major tasks, as an imager from 0.6 to 5 micron wavelength, and as a wavefront sensor to keep the 18-section mirrors functioning as one. In other wor ...

and spectrograph.
MOSCA
a 4-CCD mosaic camera, of high efficiency in the blue end of the spectra. There are two more instruments, permanently mounted on a folded-Cassegrain configuration. Retractable folding mirrors allow to switch in short time from the main instrument to either of them.
FIES
a cross-dispersed high-resolution

echelle spectrograph An echelle grating (from French ''échelle'', meaning "ladder") is a type of diffraction grating characterised by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffract ...

, isolated from thermal and mechanical instability. This is the latest addition to the telescope.
StanCam
a 1 Megapixel

. Less sensitive than ALFOSC, and with a smaller field of view, it works as a companion for NOTCam (providing optical photometry), or to react to "target of opportunity" programs when neither ALFOSC nor MOSCA are mounted.

Visitor Instruments

The NOT has been host to a number of instruments on a "visitor" status.
TURPOL
UBVRI Photopolarimeter. TURPOL has been at the NOT since the very beginning, but it is not available as part of the general instrument set.
PolCor
a combined "Lucky" imager, polarimeter, and coronagraph
LuckyCam
High frame rate, low noise

for lucky imaging
SOFIN
High resolution CCD spectrograph. This instrument was first used in 1991, spent many years usefully at the NOT, and was finally decommissioned during 2014.

Future

A new instrument for the NOT is currently under development, under the working name of NTE. This new instrument is meant to be mounted permanently in the Cassegrain focus, providing imaging and spectroscopic capabilities both in the full optical and near-infrared range.

References

External links

{{commons category
not.iac.es
- official site.
Video
- Video about and at the telescope. Optical telescopes Astronomical observatories in La Palma

Instrumentation

Visitor Instruments

Future

See also

References

External links