observatory

American Heritage Dictionary:

ob·ser·va·to·ry

(əb-zûr'və-tôr'ē, -tōr'ē) pronunciation

n., pl., -ries.

A building, place, or institution designed and equipped for making observations of astronomical, meteorological, or other natural phenomena.
A structure overlooking an extensive view.

[French observatoire (influenced by CONSERVATORY), from observer, to observe, from Old French. See observe.]

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A site, building, or orbiting platform from which astronomical measurements are, or were formerly, made, or the administrative center for such work. Equipment at most observatories detects electromagnetic radiation in some particular band and, except for large radio antennae, is usually housed in a protective dome or similar structure. Even before the invention of the telescope, observatories were built to measure the positions and movements of the Sun, the Moon, the planets, and the stars. Later, observatories, often on the outskirts of major cities such as Paris and London, used optical telescopes for more precise work in spherical astronomy and astrometry, and to investigate the nature of celestial objects, including those too faint to see with the naked eye. As telescopes increased in size, magnifying the turbulent effects of the atmosphere, the importance of clear, high-altitude observing sites grew. Large optical and infrared instruments are now always set up in locations that studies have shown to have the driest, most transparent skies on the planet, including ones in Chile, the Canary Islands, and Hawaii. Radio telescopes and interferometers observing at meter and centimeter wavelengths are less susceptible to atmospheric conditions than they are to interference from artificial radio sources, although those working at millimeter and, especially, submillimeter wavelengths suffer from atmospheric absorption and are often placed on mountaintop locations alongside their optical and infrared counterparts. Equipment designed to observe the universe at short wavelengths, including ultraviolet, X rays, and gamma rays, and in much of the infrared band, must be flown above most or all of the atmosphere aboard balloons, sounding rockets, aircraft, or, most effectively, spacecraft. Beyond the electromagnetic spectrum, instruments and observatories have been specially designed to detect cosmic rays and neutrinos, and to search for (as yet undetected) gravitational waves.

Britannica Concise Encyclopedia:

observatory

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Structure containing telescopes and other instruments for observing celestial objects and phenomena. Observatories can be classified by the part of the electromagnetic spectrum they can receive. Most are optical, observing in and near the region of the visible spectrum. Some are equipped to detect radio waves; others (space observatories) are Earth satellites and other spacecraft that carry special telescopes and detectors to study celestial sources of high-energy radiation (e.g., gamma rays, ultraviolet radiation, X-rays) from above the atmosphere. Stonehenge may have been an early predecessor of the optical observatory. Perhaps the first observatory that used instruments to accurately measure the positions of celestial objects was built c. 150 BC by Hipparchus. The first notable premodern European observatory was that at Uraniborg, built for Tycho Brahe in 1576. Observatory House, in Slough, Eng., built and operated by William Herschel (see Herschel family), was one of the technical wonders of the 18th century. Today the world's largest groupings of optical telescopes are atop Mauna Kea, in Hawaii, and Cerro Tololo, in Chile. Other major observatories include Arecibo Observatory; Mount Wilson Observatory; Palomar Observatory; and Royal Greenwich Observatory.

For more information on observatory, visit Britannica.com.

Roget's Thesaurus:

observatory

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noun

lookout

outlook

overlook

See

awareness/unawareness

McGraw-Hill Dictionary of Architecture & Construction:

observatory

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1. A structure, generally with a rotatable dome, in which astronomical observations are carried out.
2. A place, such as an upper room, which affords a wide view; a lookout.

Columbia Encyclopedia:

observatory

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observatory, scientific facility especially equipped to detect and record naturally occurring scientific phenomena. Although geological and meteorological observatories exist, the term is generally applied to astronomical observatories.

The Astronomical Observatory

The function of the astronomical observatory is centered around the telescope. In addition to visual and photographic observations of astronomical bodies and phenomena, perhaps the most valuable use of the telescope is in connection with the spectroscopic study of starlight. The total light from a star is separated into its various wavelengths (see spectrum), and the intensity of each is measured. The temperature and chemical composition of stars can be obtained by this method, as well as information about stellar motion and magnetic fields. Using computers, astronomers can measure the spectra digitally recorded by spectrographs and photometers. Observatories specializing in solar astronomy usually have coronographs and spectroheliographs. Atmospheric limitations on telescopic observations include weather conditions, air turbulence, air glow, pollution, and any source of extraneous illumination. To minimize such conditions optical observatories are generally located at high altitudes in sparsely populated areas.

See articles on specific observatories.

Development of the Astronomical Observatory

Early civilizations, such as those of Babylon, China, and Egypt, recognized the regular and periodic nature of heavenly motions and established primitive observatories to maintain astronomical records. The main purposes of these early observatories were to regulate the calendar and predict the changes of season. Because it was believed that unusual occurrences, such as comets and eclipses, foretold future events on earth, the early observatories also served a religious function, and most of the ancient astronomers were priests. Later observatories were established to compile accurate star charts and an annual ephemeris that would be of use to navigators in determining longitude at sea. For some 600 years, beginning in the 13th cent., Roman Catholic churches included solar observatories to measure the movements of the sun and so determine the correct date for Easter.

The instruments in use before the invention of the telescope include the sextant, quadrant, astrolabe, and armillary sphere. These are all calibrated sighting devices for determining the angular positions of stars and planets. The armillary sphere was the most sophisticated of these instruments. It was composed of a number of rings corresponding to great circles on the celestial sphere and was used to determine both the right ascension and the declination of a star. The last great observatory of the pretelescopic era was built by Tycho Brahe at Uranienborg, on the island of Ven, Denmark.

The invention of the telescope in the early 17th cent. revolutionized observational astronomy in two ways. First, the positions and motions of celestial bodies could be measured much more accurately with telescopes than with the earlier instruments. Such data provided a source of precise time signals. Second, the telescope could be used to analyze the physical nature of celestial bodies themselves. Until the 19th cent., telescopic images were inspected visually by highly trained observers who made drawings of what they saw. The development of dry-plate photography, which permitted long exposure times, however, offered a much more sensitive method of recording images. In the late 20th cent., electronic digital detectors utilizing charge-coupled devices (CCDs) superseded the use of film; a CCD can detect the arrival of a single photon of light. A recent development is the extension of astronomical observations to wavelengths outside the visible spectrum. Most important has been the development of radio astronomy, the study of radio waves emitted by celestial bodies.

Because the atmosphere interferes with astronomical observations from the ground, the ideal location for an observatory is beyond the earth's atmosphere. Since the late 20th cent., there has been an increasing emphasis on space-based observatories (see observatory, orbiting). Several artificial satellites have been equipped with telescopes for infrared, visible, ultraviolet, and X-ray observations. The International Ultraviolet Explorer (IUE) satellite, launched in 1978, is an 18-in. (0.45-meter) space telescope for ultraviolet studies. Launched in 1983, the Infrared Astronomy Satellite (IRAS) discovered some 246,000 infrared sources, as well as several stars around which planetary systems appear to be forming. Skylab was a manned orbiting space observatory (see space exploration). The largest space-based observatory is the Hubble Space Telescope, launched in 1990. Other observatories include the Compton Gamma-Ray Observatory, launched in 1991, and the Chandra X-ray Observatory, launched in 1999. ROSAT [ROentgen SATellite], a joint German-U.S.-British project launched in 1990, studies both X-ray and ultraviolet wavelengths never before imaged from space. It has detected a new class of bright stars that shine only in the ultraviolet part of the spectrum. The Cosmic Background Explorer (1989-93) studied microwave background radiation that no star or other known object could emit-it is believed to have come from the creation of the universe (see cosmology).

The computer age has also impacted observatories in several ways. Instead of being cast in one piece, reflecting telescope mirrors can be constructed of numerous small segments that move under computer control to focus the light and create an image equivalent to that of a much larger telescope. This has made it economically possible for observatories to reach further and further into the cosmos. Computers have also made it easier to construct and retrieve information from archival data bases. Computer networks are under construction that will make it possible for these archival databases to be made available to other observatories so as to create a virtual observatory, with gains in productivity and cost-effectiveness for the observatories that participate in it.

Devil's Dictionary:

observatory

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A cynical view of the world by Ambrose Bierce

A place where astronomers conjecture away the guesses of their predecessors.

Word Tutor:

observatory

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IN BRIEF: A building housing large telescopes.

The astronomers put on yet another kettle for tea in the in the cold and dark of the observatory high on the mountain.

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Random House Word Menu:

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Branches, Laws, Theories, and Techniques - observatory: building equipped with large telescope and other devices used for astronomical studies

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Bradford's Crossword Solver's Dictionary:

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Wikipedia on Answers.com:

Observatory

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This article is about scientific observatories. For the suburb of Cape Town, see Observatory, Cape Town. For other uses, see The Observatory (disambiguation).

The Sphinx Observatory at the Jungfraujoch in the Swiss Alps; high altitude observatories are less affected by the atmosphere.

An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena).

Contents

1 Astronomical observatories
2 Volcano observatories
3 See also
4 References
5 Further reading
6 External links

Astronomical observatories

Ground-based observatories

Paranal Observatory, home of the Very Large Telescope, a cluster of four large (8.2 meter diameter) telescopes.

Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes.

For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the Earth's atmosphere is thinner thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing".^[1] Sites that meet the above criteria for modern observatories include the southwestern United States, Hawaii, Canary Islands, the Andes, and high mountains in Mexico such as Sierra Negra.^[2] Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the USA, Roque de los Muchachos Observatory in Spain, and Paranal Observatory in Chile.

Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A - a place in the central part of Eastern Antarctica.^[3] This location provides the least atmospheric disturbances and best visibility.

Radio observatories

Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to see space very close up. Such an instrument, or a collection of them, with outbuildings for such things as control centres, data reduction centers, and maintenance are called radio observatories. Radio observatories are similarly located far from major centers of population to avoid electromagnetic interference (EMI) from radio, TV, radar, and other EMI emitting devices. But unlike optical observatories, radio observatories will be placed in valleys to further shield them from EMI. Some of the major radio observatories are at Socorro, in New Mexico, USA, Jodrell Bank in the UK, Arecibo, Puerto Rico, Parkes in New South Wales, Australia and Chajnantor in Chile.

Highest astronomical observatories

Main article: List of highest astronomical observatories

Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes, above 4000–5000 m (13,000-16,000 ft). The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4205 m (13,796 ft) volcano in Hawaii. The Chacaltaya Astrophysical Observatory in Bolivia, at 5230 m (17,160 ft), was the world's highest permanent astronomical observatory^[4] from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory,^[5] an optical-infrared telescope on a remote 5640 m (18,500 ft) mountaintop in the Atacama Desert of Chile.

Oldest astronomical observatories

"El Caracol" observatory temple at Chichen Itza, Mexico.

The oldest proto-observatories, in the sense of a private observation post,^[6] include:

Remains of the Maragheh observatory now under a modern protective dome at Maragheh, Iran.

Jantar Mantar in Jaipur, India.

The oldest true observatories, in the sense of a specialized research institute,^[7]^[8]^[9] include:

c.150 BC: Observatory at Rhodes, Greece^[10]
825 AD: Al-Shammisiyyah observatory, Baghdad, Iraq
869: Mahodayapuram Observatory, Kerala, India
1259: Maragheh observatory, Iran
1276: Gaocheng Astronomical Observatory, China
1420: Samarqand observatory, Uzbekistan
1442: Beijing Ancient Observatory, China
1577: Istanbul observatory of Taqi al-Din, Turkey
1580: Uraniborg, Denmark
1581: Stjerneborg, Denmark
1642: Round Tower, Denmark
1633: Leiden Observatory, Netherlands
1667: Paris Observatory, France
1675: Royal Greenwich Observatory, England
1711: Berlin Observatory, Germany
1724: Yantra Mantra, India
1785: Dunsink Observatory, Ireland
1789: Armagh Observatory, Northern Ireland
1830/1842: Depot of Charts & Instruments/US Naval Observatory,^[11]^[12] USA
1830: Yale University Observatory Atheneum, USA
1836: Hopkins Observatory, Williams College, USA
1839/1847: Harvard College Observatory, USA
1842: Cincinnati Observatory, USA
1884: McCormick Observatory, USA
1890: Smithsonian Astrophysical Observatory, USA
1894: Lowell Observatory, USA

Space-based observatories

The Hubble Space Telescope, a space-based observatory

Main article: Space observatory

Space-based observatories are telescopes or other instruments that are located in outer space, many in orbit around the Earth. Space-based observatories can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is opaque to ultraviolet radiation, X-rays, and gamma rays and is partially opaque to infrared radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet.^[13] Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations.^[14] As a result, the angular resolution of space telescopes such as the Hubble Space Telescope is often much smaller than a ground-based telescope with a similar aperture. However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all.

Airborne observatories

Main article: Airborne observatory

Airborne observatories have the advantage of height over ground installations, putting them above most of the Earth's atmosphere. But they also have an advantage over space telescopes - the instruments can be deployed, repaired, updated much more quickly and inexpensively. The Kuiper Airborne Observatory and the Stratospheric Observatory for Infrared Astronomy use airplanes to observe in the infrared, which is absorbed by water vapor in the atmosphere. Balloons for X-ray astronomy have been used in a variety of countries.

Volcano observatories

Main article: Volcano observatory

A volcano observatory is an institution that conducts research and monitoring of a volcano. Among the best known are the Hawaiian Volcano Observatory and the Vesuvius Observatory. Mobile volcano observatories exist with the USGS VDAP (Volcano Disaster Assistance Program), to be deployed on demand.

References

^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall. pp. 116–119.
^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall. p. 119.
^ Saunders, Will; Lawrence, Jon S.; Storey, John W. V.; Ashley, Michael C. B.; Kato, Seiji; Minnis, Patrick; Winker, David M.; Liu, Guiping et al (2009). "Where Is the Best Site on Earth? Domes A, B, C, and F, and Ridges A and B". Publications of the Astronomical Society of the Pacific 121 (883): 976–992. Bibcode 2009PASP..121..976S. doi:10.1086/605780
^ Zanini, A.; Storini, M., and Saavedra, O. (2009). "Cosmic rays at High Mountain Observatories". Advances in Space Research 44 (10): 1160–1165. Bibcode 2009AdSpR..44.1160Z. doi:10.1016/j.asr.2008.10.039. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3S-4WNRK63-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3a0ae82052350bedd47f84b975d88687.
^ Yoshii, Yuzuru; et al (Aug 11, 2009). "The 1m telescope at the Atacama Observatory has Started Scientific Operation, detecting the Hydrogen Emission Line from the Galactic Center in the Infrared Light". Press Release. School of Science, the University of Tokyo. http://www.s.u-tokyo.ac.jp/press/press-2009-15en.html. Retrieved 21 December 2009.
^ Micheau, Francoise. "The Scientific Institutions in the Medieval Near East". pp. 992–3 , in (Rashed & Morelon 1996, pp. 985–1007)
^ Peter Barrett (2004), Science and Theology Since Copernicus: The Search for Understanding, p. 18, Continuum International Publishing Group, ISBN 0-567-08969-X
^ Micheau, Francoise. "The Scientific Institutions in the Medieval Near East". pp. 992–3 , in Rashed, Roshdi; Morelon, Régis (1996). Encyclopedia of the History of Arabic Science. Routledge. pp. 985–1007. ISBN 0415124107
^ Kennedy, Edward S. (1962). "Review: The Observatory in Islam and Its Place in the General History of the Observatory by Aydin Sayili". Isis 53 (2): 237–239. doi:10.1086/349558
^ "Facts about Hipparchus: astronomical observatory, as discussed in astronomical observatory:". Encyclopædia Britannica.
^ "National Park Service: Astronomy and Astrophysics (United States Naval Observatory)". Cr.nps.gov. 2001-11-05. http://www.cr.nps.gov/history/online_books/butowsky5/astro4g.htm. Retrieved 2011-11-03.
^ Portolano, M. (2000). "John Quincy Adams's Rhetorical Crusade for Astronomy". Isis 91 (3): 480–503. doi:10.1086/384852. JSTOR 237905. PMID 11143785. edit
^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall.
^ "A Brief History of the Hubble Space Telescope: Why a Space Telescope?". NASA. http://history.nasa.gov/hubble/index.html. Retrieved 2006-08-14.

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Translations:

Observatory

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Dansk (Danish)
n. - observatorium

Nederlands (Dutch)
sterrenwacht, observatorium

Français (French)
n. - observatoire

Deutsch (German)
n. - Observatorium, Sternwarte, Wetterstation

Ελληνική (Greek)
n. - (αστρον.) αστεροσκοπείο, παρατηρητήριο

Italiano (Italian)
osservatorio

Português (Portuguese)
n. - observatório (m)

Русский (Russian)
обсерватория

Español (Spanish)
n. - observatorio

Svenska (Swedish)
n. - observatorium

中文（简体）(Chinese (Simplified))
天文台, 了望台, 气象台

中文（繁體）(Chinese (Traditional))
n. - 天文臺, 瞭望台, 氣象臺

한국어 (Korean)
n. - 관측소, 천문대, 기상대

日本語 (Japanese)
n. - 観測所, 天文台, 気象台, 展望台

العربيه (Arabic)
‏(الاسم) مرصد‏

עברית (Hebrew)
n. - ‮מצפה כוכבים‬

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		American Heritage Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved. Read more
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		Britannica Concise Encyclopedia. Britannica Concise Encyclopedia. © 1994-2012 Encyclopædia Britannica, Inc. All rights reserved. Read more
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		McGraw-Hill Dictionary of Architecture & Construction. McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc. All rights reserved. Read more
		Columbia Encyclopedia. The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2012, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/. Read more
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		Bradford's Crossword Solver's Dictionary. Collins Bradford's Crossword Solver's Dictionary © Anne Bradford, 1986, 1993, 1997, 2000, 2003, 2005, 2008 HarperCollins Publishers All rights reserved. Read more
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	obs. (abbreviation)
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observatory

ob·ser·va·to·ry

observatory

observatory

observatory

observatory

observatory

observatory

observatory

categories related to 'observatory'

observatory

observatory

Observatory

Astronomical observatories

Ground-based observatories

Radio observatories

Highest astronomical observatories

Oldest astronomical observatories

Space-based observatories

Airborne observatories

Volcano observatories

See also

References

Further reading

External links

Observatory