An astronomical instrument is a device for observing, measuring, or recording astronomical data.[ citation needed ] They are used in the scientific field of astronomy, a natural science that studies celestial objects and the phenomena that occur in the cosmos, with the object of explaining their origin and evolution over time. Many are also used in navigation and surveying.
Astronomical instruments include:
The history of astronomy focuses on the contributions civilizations have made to further their understanding of the universe beyond earth's atmosphere. Astronomy is one of the oldest natural sciences, achieving a high level of success in the second half of the first millennium. Astronomy has origins in the religious, mythological, cosmological, calendrical, and astrological beliefs and practices of prehistory. Early astronomical records date back to the Babylonians around 1000 BCE. There is also astronomical evidence of interest from early Chinese, Central American and North European cultures.
The following outline is provided as an overview and topical guide to space science:
An astrolabe is an astronomical instrument dating to ancient times. It serves as a star chart and physical model of visible half-dome of the sky. Its various functions also make it an elaborate inclinometer and an analog calculation device capable of working out several kinds of problems in astronomy. In its simplest form it is a metal disc with a pattern of wires, cutouts, and perforations that allows a user to calculate astronomical positions precisely. It is able to measure the altitude above the horizon of a celestial body, day or night; it can be used to identify stars or planets, to determine local latitude given local time, to survey, or to triangulate. It was used in classical antiquity, the Islamic Golden Age, the European Middle Ages and the Age of Discovery for all these purposes.
An armillary sphere is a model of objects in the sky, consisting of a spherical framework of rings, centered on Earth or the Sun, that represent lines of celestial longitude and latitude and other astronomically important features, such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. It was invented separately, in ancient China possibly as early as the 4th century BC and ancient Greece during the 3rd century BC, with later uses in the Islamic world and Medieval Europe.
Photometric-standard stars are a series of stars that have had their light output in various passbands of photometric system measured very carefully. Other objects can be observed using CCD cameras or photoelectric photometers connected to a telescope, and the flux, or amount of light received, can be compared to a photometric-standard star to determine the exact brightness, or stellar magnitude, of the object.
The torquetum or turquet is a medieval astronomical instrument designed by persons unknown to take and convert measurements made in three sets of coordinates: horizon, equatorial, and ecliptic. It is characterised by R. P. Lorch as a combination of Ptolemy's astrolabon and the plane astrolabe. In a sense, the torquetum is an analog computer.
The Constantinople observatory of Taqi ad-Din, founded in Constantinople by Taqi ad-Din Muhammad ibn Ma'ruf in 1577, was one of the largest astronomical observatories in the pre-modern world. However, it only existed for a few years and was destroyed in 1580.
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" system also took shape around this period, by the time of King Wu Ding.
The triquetrum was the medieval name for an ancient astronomical instrument first described by Ptolemy in the Almagest. Also known as Parallactic Rulers, it was used for determining altitudes of heavenly bodies. Ptolemy calls it a "parallactic instrument" and seems to have used it to determine the zenith distance and parallax of the Moon.
Navigational instruments are instruments used by nautical navigators and pilots as tools of their trade. The purpose of navigation is to ascertain the present position and to determine the speed, direction, etc. to arrive at the port or point of destination.
The Jantar Mantar is a collection of 19 astronomical instruments built by the Rajput king Sawai Jai Singh, the founder of Jaipur, Rajasthan. The monument was completed in 1734. It features the world's largest stone sundial, and is a UNESCO World Heritage Site. It is near City Palace and Hawa Mahal. The instruments allow the observation of astronomical positions with the naked eye. The observatory is an example of the Ptolemaic positional astronomy which was shared by many civilizations.
Jantar Mantar is located in the modern city of New Delhi. "Jantar Mantar" means "instruments for measuring the harmony of the heavens". It consists of 13 architectural astronomy instruments. The site is one of five built by Maharaja Jai Singh II of Jaipur, from 1723 onwards, revising the calendar and astronomical tables. Jai Singh, born in 1688 into a royal Rajput family that ruled the regional kingdom, was born into an era of education that maintained a keen interest in astronomy. There is a plaque fixed on one of the structures in the Jantar Mantar observatory in New Delhi that was placed there in 1910 mistakenly dating the construction of the complex to the year 1710. Later research, though, suggests 1724 as the actual year of construction. Its height is 723 feet (220 m).
Medieval Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age, and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. It closely parallels the genesis of other Islamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science with Islamic characteristics. These included Greek, Sassanid, and Indian works in particular, which were translated and built upon.
The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes mounted so as to allow pointing only in the meridian, the great circle through the north point of the horizon, the north celestial pole, the zenith, the south point of the horizon, the south celestial pole, and the nadir. Meridian telescopes rely on the rotation of the sky to bring objects into their field of view and are mounted on a fixed, horizontal, east–west axis.
An equatorium is an astronomical calculating instrument. It can be used for finding the positions of the Moon, Sun, and planets without arithmetic operations, using a geometrical model to represent the position of a given celestial body.
The Extreme Ultraviolet Explorer was a NASA space telescope for ultraviolet astronomy. EUVE was a part of NASA's Explorer spacecraft series. Launched on 7 June 1992 with instruments for ultraviolet (UV) radiation between wavelengths of 7 and 76 nm, the EUVE was the first satellite mission especially for the short-wave ultraviolet range. The satellite compiled an all-sky survey of 801 astronomical targets before being decommissioned on 31 January 2001.
A quadrant is an instrument used to measure angles up to 90°. Different versions of this instrument could be used to calculate various readings, such as longitude, latitude, and time of day. Its earliest recorded usage was in ancient India in Rigvedic times by Rishi Atri to observe a solar eclipse. It was then proposed by Ptolemy as a better kind of astrolabe. Several different variations of the instrument were later produced by medieval Muslim astronomers. Mural quadrants were important astronomical instruments in 18th-century European observatories, establishing a use for positional astronomy.
In astronomy, a transit instrument is a small telescope with extremely precisely graduated mount used for the precise observation of star positions. They were previously widely used in astronomical observatories and naval observatories to measure star positions in order to compile nautical almanacs for use by mariners for celestial navigation, and observe star transits to set extremely accurate clocks which were used to set marine chronometers carried on ships to determine longitude, and as primary time standards before atomic clocks. The instruments can be divided into three groups: meridian, zenith, and universal instruments.
Astronomical rings, also known as Gemma's rings, are an early astronomical instrument. The instrument consists of three rings, representing the celestial equator, declination, and the meridian.
