The Galileo National Telescope, ( it, Telescopio Nazionale Galileo; TNG;

code In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...

: Z19) is a 3.58-meter

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

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 the

Roque de los Muchachos Observatory Roque de los Muchachos Observatory ( es, Observatorio del Roque de los Muchachos, ORM) is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, Spain. The observatory site is operated ...

on the island of

La Palma La Palma (, ), also known as ''La isla bonita'' () and officially San Miguel de La Palma, is the most north-westerly island of the Canary Islands, Spain. La Palma has an area of making it the fifth largest of the eight main Canary Islands. The ...

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 ...

, Spain. The TNG is operated by the "Fundación Galileo Galilei, Fundación Canaria", a non-profit institution, on behalf of the Italian National Institute of Astrophysics (INAF). The telescope saw first light in 1998 and is named after the Italian

Renaissance The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...

astronomer

Galileo Galilei Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He was ...

. Observations at the TNG can be proposed through the Italian Time Allocation Committee (TAC) which assigns, based on the scientific merit of the proposals, 75% of the available time. The rest of the time is at disposal of the Spanish and international astronomical communities. The TNG is open to new proposals two times a year, typically in March–April and September–October.

Technical characteristics

The TNG is an altazimuthal reflecting telescope with a Ritchey-Chretien optical configuration and a flat tertiary mirror feeding two opposite Nasmyth foci. It has a design derived from the

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 ...

(NTT), an

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 ...

4-meters class telescope located in La Silla (Chile). Therefore, the optical quality of the telescope is ensured by an

active optics Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active op ...

system performing real-time corrections of the optical components and compensating, in particular, for the deformations of the primary mirror, which is too thin to be completely rigid. The interface between the telescope fork and the instruments at both Nasmyth foci is provided by two rotator/adapters. Their main function is to compensate for the field rotation by a mechanical counter rotation. The best quality of the TNG is that all the available instruments are permanently mounted at the telescope. This guarantees flexibility during an observing session, since it is possible to change instrument during the night with a loss of time limited to a few minutes. The science based on observational data from the TNG is varied. Proposed observing programs go from the study of the planets and minor bodies of the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

up to researches of cosmological interest (e.g.

large-scale structure of the Universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these obj ...

and systems of galaxies).

Scientific instruments

The TNG is equipped with five instruments: * ''

HARPS-N HARPS-N, the ''High Accuracy Radial velocity Planet Searcher for the Northern hemisphere'' is a high-precision radial-velocity spectrograph, installed at the Italian Telescopio Nazionale Galileo, a 3.58-metre telescope located at the Roque de los ...

'' ("High Accuracy Radial velocity Planet Searcher"), echelle spectrograph dedicated to the discovery of

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

s; * ''DOLoRes'' ("Device Optimized for the Low Resolution"), CCD camera and low-resolution

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 ...

for observations in the visible band; * ''NICS'' ("Near Infrared Camera and Spectrometer"), camera and spectrograph for observations in the near-

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

; * ''GIANO'', high-resolution echelle spectrograph for observations in the near-

; * ''SiFAP2'', extremely fast optical photometer. Decommissioned instruments: * ''SARG'' ("Spettrografo ad Alta Risoluzione del Galileo"), high-resolution spectrograph for observations in the visible band; * ''OIG'' ("Optical Imager Galileo"), CCD camera dedicated to optical images at high resolution; * ''Speckle camera'', dedicated to observations in the visible band at the

diffraction Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a s ...

limit of the telescope; * ''AdOpt@TNG'', adaptive optics system working in the near-infrared.

References

External links

Official website

TNG News Page (TNG News)

Scientific publications based on data taken at the TNG

* {{Galileo Galilei, state=collapsed Optical telescopes Astronomical observatories in La Palma Galileo Galilei

Technical characteristics

Scientific instruments

See also

References

External links