Infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in infrared (IR) radiation. Visible radiation ranges from 400nm (blue) to 700nm (red). Longer wavelengths than 700nm but still shorter than microwaves are called infrared (or sometimes submillimeter waves). Astrometry: the study of the position of objects in the sky and their changes of position. ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature and chemical composition) of astronomical objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ... Microwave Slang for small waves, like at a beach, often used by surfers. ...

Scientists classify infrared astronomy as part of optical astronomy because optical components (mirrors, lenses and solid state digital detectors) are usually used. Optical astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light. ...

Discovery

After the use of prisms by Isaac Newton to split white light into a spectrum, it was found in 1800 by William Herschel that the hottest part of the band of light from the Sun was actually past the red end of the spectrum. These "heat rays" even displayed some spectral lines. Charles Piazzi Smyth in 1856 detected infrared radiation in the light of the Moon. If a shaft of light entering a prism is sufficiently small such that the coloured edges meet, a spectrum results In optics, a prism is a device used to refract light, reflect it or break it up (to disperse it) into its constituent spectral colours (colours of the rainbow). ... Jump to: navigation, search Sir Isaac Newton at 46 in Godfrey Knellers 1689 portrait Sir Isaac Newton, PRS (25 December 1642 (OS) – 20 March 1727 (OS) / 4 January 1643 (NS) – 31 March 1727 (NS)) was an English physicist, mathematician, astronomer, philosopher, and alchemist. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... 1800 was a common year starting on Wednesday (see link for calendar). ... Sir Wilhelm Friedrich Herschel (Hanover, November 15, 1738 – August 25, 1822 Slough, then in Buckinghamshire now in Berkshire) was a German-born British astronomer and composer who became famous for discovering the planet Uranus, and made many other astronomical discoveries. ... A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. ... Charles Piazzi Smyth (January 3, 1819 – February 21, 1900), was Astronomer Royal of Scotland from 1846 to 1888. ... Jump to: navigation, search 1856 was a leap year starting on Tuesday (see link for calendar). ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ...

Modern Infrared Astronomy

Near infrared radiation (infrared radiation with wavelengths close to that of visible light) behaves in a very similar way to visible light, and can be detected using similar electronic devices. For this reason, the near infrared region of the spectrum is commonly incorporated as part of the "optical" spectrum, along with the near ultraviolet (most scientific instruments such as optical telescopes cover the near infrared as well as the visible). The far infrared extends to submillimeter wavelengths, which are observed by telescopes such as the James Clerk Maxwell Telescope at Mauna Kea Observatory. The James Clerk Maxwell Telescope (JCMT) is a 15-metre submillimetre-wavelength telescope at Mauna Kea Observatory in Hawaii. ... The Mauna Kea Observatory, an institute of the University of Hawaii, is considered one of the most important land-based observatories in the world for its isolated, unobstructed views of space without interference from man-made light sources. ...

Like all other forms of electromagnetic radiation, infrared is utilised by astronomers to learn more about the universe. As infrared is esentially heat radiation, infrared telescopes (which include most major optical telescopes as well as a few dedicated infrared telescopes) need to have their detectors shielded from heat and chilled with liquid nitrogen in order to actually form images. This is particularly important in the mid infrared and far infrared regions of the spectrum. The principle limitation on infrared sensitivity from ground-based telescopes is the water vapour in the Earth's atmosphere, which absorbs a lot of infrared radiation. For this reason most infrared telescopes are built in very dry places at high altitude (above most of the water vapour in the atmosphere). Suitable locations on Earth include Mauna Kea Observatory at 4205 meters above sea level, the ALMA site at 5000m in Chile and regions of high altitude ice-desert such as Dome C in Antarctic. Klystrons give off both ionizing and electromagnetic radiation. ... An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... Jump to: navigation, search The deepest visible-light image of the cosmos. ... 50 cm refracting telescope at Nice Observatory. ... Jump to: navigation, search Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. ... The Mauna Kea Observatory, an institute of the University of Hawaii, is considered one of the most important land-based observatories in the world for its isolated, unobstructed views of space without interference from man-made light sources. ... ALMAs logo The Atacama Large Millimeter Array (ALMA) is an international astronomy project that consists of a system of radio telescopes in an array formation, located in the Atacama desert in northern Chile. ... Dome C, also known as Dome Circe or Dome Charlie, ( 75° S 123° E) is a local feature of the Antarctic Plateau, and site of the Concordia scientific station. ... Greek ἀνταρκτικός, opposite the arctic) is a continent surrounding the Earths South Pole. ...

However, as with visible-light telescopes, space is the ideal place for their use and most optical telescopes launched into space (such as the Hubble Space Telescope) can also perform infrared observations. The recently launched Spitzer Space Telescope is dedicated soley to infrared observations. The Hubble Space Telescope is a telescope in orbit around the Earth. ... The Spitzer Space Telescope (SST) (formerly the Space Infrared Telescope Facility (SIRTF)) is an infrared space observatory, the fourth and final of NASAs Great Observatories. ...

The highest resolution infrared observations are performed by ground-based astronomical interferometers. Optical interferometry is a technique of interferometry combining light from multiple sources in an optical instrument in order to make various precise measurements. ...

Infrared Technology

The cheapest infrared detectors commonly used at research telescopes are HgCdTe arrays. These operate well between 1 micron and 5 micron wavelengths. For longer wavelength observations or higher sensitivity other detectors may be used, including other narrow gap semiconductor detectors, low temperature bolometer arrays or photon-counting Superconducting Tunnel Junction arrays. HgCdTe (mercury cadmium telluride) is an alloy of CdTe and HgTe and is third for technological importance after Si and GaAs. ... The word micron has at least two possible meanings: A micrometre (American spelling: micrometer, symbol µm), that is, one millionth of a metre. ... The word micron has at least two possible meanings: A micrometre (American spelling: micrometer, symbol µm), that is, one millionth of a metre. ... Jump to: navigation, search Narrow gap semiconductors are semiconducting materials with an energy gap that is comparatuively small comapred to silicon. ...

Astronomers' Infrared Spectrum

Infrared space telescopes such as Spitzer, IRAS, ISO and the forthcoming Herschel Space Observatory can observe across the almost all of the infrared spectrum. However, most infrared astronomy is still done at ground-based telescopes, and these are limited to observations through a small number of spectral "windows", at wavelengths where the Earth's atmosphere is transparent. The main infrared windows are listed below: The Spitzer Space Telescope (SST) (formerly the Space Infrared Telescope Facility (SIRTF)) is an infrared space observatory, the fourth and final of NASAs Great Observatories. ... The Infrared Astronomical Satellite (IRAS) was a space-based observatory that performed a survey of the entire sky at infrared wavelengths. ... The Infrared Space Observatory (ISO)is a space telescope for infrared light designed and operated by the European Space Agency (ESA). ... The Herschel Space Observatory is a mission of the European Space Agency. ...

Between these windows there are generally regions where infrared observations are more difficult or impossible from the ground due to the opacity of the atmosphere. Dedicated infrared and submillimeter telescopes are generally built at very high altitude sites like Mauna Kea Observatory, Hawaii and the ALMA site in Chile, or even flown on aircraft like SOFIA, providing the best sensitivity available from Earth based observatories. Data from space-based observatories like Spitzer, IRAS and ISO help fill in the gaps between the atmospheric windows listed above. The Mauna Kea Observatory, an institute of the University of Hawaii, is considered one of the most important land-based observatories in the world for its isolated, unobstructed views of space without interference from man-made light sources. ... State nickname: The Aloha State Other U.S. States Capital Honolulu Largest city Honolulu Governor Linda Lingle (R) Senators Daniel Inouye (D) Daniel Akaka (D) Official languages Hawaiian and English Area 28,337 km² (43rd)  - Land 16,649 km²  - Water 11,672 km² (41. ... ALMAs logo The Atacama Large Millimeter Array (ALMA) is an international astronomy project that consists of a system of radio telescopes in an array formation, located in the Atacama desert in northern Chile. ... The city of Sofia (Bulgarian: София), at the foot of the Vitosha mountain, has a population of 1,208,930 (2003), and is the biggest city and capital of the Republic of Bulgaria. ... The Spitzer Space Telescope (SST) (formerly the Space Infrared Telescope Facility (SIRTF)) is an infrared space observatory, the fourth and final of NASAs Great Observatories. ... The Infrared Astronomical Satellite (IRAS) was a space-based observatory that performed a survey of the entire sky at infrared wavelengths. ... The Infrared Space Observatory (ISO)is a space telescope for infrared light designed and operated by the European Space Agency (ESA). ...

See also

• Far infrared astronomy
• Most telescopes listed in Category:Telescopes can observe at some infrared wavelengths