A star chart is a celestial map of the night sky with astronomical objects laid out on a grid system. They are used to identify and locate constellations, stars, nebulae, galaxies, and planets. [1] They have been used for human navigation since time immemorial. [2] Note that a star chart differs from an astronomical catalog, which is a listing or tabulation of astronomical objects for a particular purpose. Tools using a star chart include the astrolabe and planisphere.
A variety of archaeological sites and artifacts found are thought to indicate ancient made star charts.
The oldest known star chart may be a carved ivory Mammoth tusk, drawn by early people from Asia who moved into Europe, that was discovered in Germany in 1979. This artifact is 32,500 years old and has a carving that resembles the constellation Orion, although it could not be confirmed and could also be a pregnancy chart. [3]
German researcher Dr Michael Rappenglueck, of the University of Munich, has suggested that drawing on the wall of the Lascaux caves in France could be a graphical representation of the Pleiades open cluster of stars. This is dated from 33,000 to 10,000 years ago. He also suggested a panel in the same caves depicting a charging bison, a man with a bird's head and the head of a bird on top of a piece of wood, together may depict the Summer Triangle, which at the time was a circumpolar formation. [4] Rappenglueck also discovered a drawing of the Northern Crown constellation in the cave of El Castillo (North of Spain), made in the same period as the Lascaux chart. [5]
Another star chart panel, created more than 21,000 years ago, was found in the La Tête du Lion cave (fr). The bovine in this panel may represent the constellation Taurus, with a pattern representing the Pleiades just above it. [6]
A star chart drawn 5000 years ago by the Indians in Kashmir, which also depict a supernova for the first time in human history. [7] The Nebra sky disk, a 30 cm wide bronze disk dated to 1600 BC, bears gold symbols generally interpreted as a sun or full moon, a lunar crescent, several stars including the Pleiades cluster and possibly the Milky Way.
The oldest accurately dated star chart appeared in ancient Egyptian astronomy in 1534 BC. [8] The earliest known star catalogues were compiled by the ancient Babylonian astronomers of Mesopotamia in the late 2nd millennium BC, during the Kassite Period (ca. 1531–1155 BC). [9] The oldest records of Chinese astronomy date to the Warring States period (476–221 BC), but the earliest preserved Chinese star catalogues of astronomers Shi Shen and Gan De are found in the 2nd-century BC Shiji by the Western Han historian Sima Qian. [10] The oldest Chinese graphical representation of the night sky is a lacquerware box from the 5th-century BC Tomb of Marquis Yi of Zeng, although this depiction shows the positions of the Chinese constellations by name and does not show individual stars. [11]
The Farnese Atlas is a 2nd-century AD Roman copy of a Hellenistic era Greek statue depicting the Titan Atlas holding the celestial sphere on his shoulder. It is the oldest surviving depiction of the ancient Greek constellations, and includes grid circles that provide coordinate positions. Because of precession, the positions of the constellations slowly change over time. By comparing the positions of the 41 constellations against the grid circles, an accurate determination can be made of the epoch when the original observations were performed. Based upon this information, the constellations were catalogued at 125 ± 55 BC. This evidence indicates that the star catalogue of the 2nd-century BC Greek astronomer Hipparchus was used. [12]
A Roman era example of a graphical representation of the night sky is the Ptolemaic Egyptian Dendera zodiac, dating from 50 BC. This is a bas relief sculpting on a ceiling at the Dendera Temple complex. It is a planisphere depicting the zodiac in graphical representations. However, individual stars are not plotted. [13]
The oldest surviving manuscript star chart was the Dunhuang Star Chart, dated to the Tang dynasty (618–907) and discovered in the Mogao Caves of Dunhuang in Gansu, Western China along the Silk Road. This is a scroll 210 cm in length and 24.4 cm wide showing the sky between declinations 40° south to 40° north in twelve panels, plus a thirteenth panel showing the northern circumpolar sky. A total of 1,345 stars are drawn, grouped into 257 asterisms. The date of this chart is uncertain, but is estimated as 705–10 AD. [14] [15] [16]
During the Song dynasty (960–1279), the Chinese astronomer Su Song wrote a book titled Xin Yixiang Fa Yao (New Design for the Armillary Clock) containing five maps of 1,464 stars. This has been dated to 1092. In 1193, the astronomer Huang Shang prepared a planisphere along with explanatory text. It was engraved in stone in 1247, and this chart still exists in the Wen Miao temple in Suzhou. [15]
In Muslim astronomy, the first star chart to be drawn accurately was most likely the illustrations produced by the Persian astronomer Abd al-Rahman al-Sufi in his 964 work titled Book of Fixed Stars . This book was an update of parts VII.5 and VIII.1 of the 2nd century Almagest star catalogue by Ptolemy. The work of al-Sufi contained illustrations of the constellations and portrayed the brighter stars as dots. The original book did not survive, but a copy from about 1009 is preserved at the Oxford University. [14] [15]
Perhaps the oldest European star map was a parchment manuscript titled De Composicione Spere Solide. It was most likely produced in Vienna, Austria in 1440 and consisted of a two-part map depicting the constellations of the northern celestial hemisphere and the ecliptic. This may have served as a prototype for the oldest European printed star chart, a 1515 set of woodcut portraits produced by Albrecht Dürer in Nuremberg, Germany. [17]
During the European Age of Discovery, expeditions to the southern hemisphere began to result in the addition of new constellations. These most likely came from the records of two Dutch sailors, Pieter Dirkszoon Keyser and Frederick de Houtman, who in 1595 traveled together to the Dutch East Indies. Their compilations resulted in the 1601 globe of Jodocus Hondius, who added 12 new southern constellations. Several other such maps were produced, including Johann Bayer's Uranometria in 1603. [18] The latter was the first atlas to chart both celestial hemispheres and it introduced the Bayer designations for identifying the brightest stars using the Greek alphabet. The Uranometria contained 48 maps of Ptolemaic constellations, a plate of the southern constellations and two plates showing the entire northern and southern hemispheres in stereographic polar projection. [19]
Polish astronomer Johannes Hevelius published his Firmamentum Sobiescianum star atlas posthumously in 1690. It contained 56 large, double page star maps and improved the accuracy in the position of the southern stars. He introduced 11 more constellations, including Scutum, Lacerta, and Canes Venatici.
In 1824 Sidney Hall produced a set of star charts called Urania's Mirror. They are illustrations based on Alexander Jamieson's A Celestial Atlas, but the addition of holes punched in them allowed them to be held up to a light to see a depiction of the constellation's stars.
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
Hydrus is a small constellation in the deep southern sky. It was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm (14 in) diameter celestial globe published in late 1597 in Amsterdam by Plancius and Jodocus Hondius. The first depiction of this constellation in a celestial atlas was in Johann Bayer's Uranometria of 1603. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. Its name means "male water snake", as opposed to Hydra, a much larger constellation that represents a female water snake. It remains below the horizon for most Northern Hemisphere observers.
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.
A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, and this article covers only some of the more frequently quoted ones. Star catalogues were compiled by many different ancient people, including the Babylonians, Greeks, Chinese, Persians, and Arabs. They were sometimes accompanied by a star chart for illustration. Most modern catalogues are available in electronic format and can be freely downloaded from space agencies' data centres. The largest is being compiled from the spacecraft Gaia and thus far has over a billion stars.
Taurus is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head.
The Pleiades, also known as Seven Sisters and Messier 45, is an asterism of an open star cluster containing young B-type stars in the northwest of the constellation Taurus. At a distance of about 444 light-years, it is among the nearest star clusters to Earth and the nearest Messier object to Earth, being the most obvious star cluster to the naked eye in the night sky. It is also observed to house the reflection nebula NGC 1432, an HII region.
Timeline of astronomical maps, catalogs and surveys
Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials".
Orion is a prominent set of stars visible during winter in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century astronomer Ptolemy. It is named after a hunter in Greek mythology.
Columba is a faint constellation designated in the late sixteenth century, remaining in official use, with its rigid limits set in the 20th century. Its name is Latin for dove. It takes up 1.31% of the southern celestial hemisphere and is just south of Canis Major and Lepus.
In astronomy, a planisphere is a star chart analog computing instrument in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date. It is an instrument to assist in learning how to recognize stars and constellations. The astrolabe, an instrument that has its origins in Hellenistic astronomy, is a predecessor of the modern planisphere. The term planisphere contrasts with armillary sphere, where the celestial sphere is represented by a three-dimensional framework of rings.
Canopus is the brightest star in the southern constellation of Carina and the second-brightest star in the night sky. It is also designated α Carinae, which is romanized (transliterated) to Alpha Carinae. With a visual apparent magnitude of −0.74, it is outshone only by Sirius.
The Farnese Atlas is a 2nd-century CE Roman marble sculpture of Atlas holding up a celestial globe. Probably a copy of an earlier work of the Hellenistic period, it is the oldest extant statue of Atlas, a Titan of Greek mythology who is represented in earlier Greek vase painting, and the oldest known representation of the celestial sphere and the classical constellations. The sculpture is at the National Archaeological Museum of Naples, in Italy.
Uranometria is a star atlas produced by Johann Bayer. It was published in Augsburg in 1603 by Christoph Mang under the full title Uranometria: omnium asterismorum continens schemata, nova methodo delineata, aereis laminis expressa. The word "uranometria", from Ancient Greek οὐρανός (ouranós) 'sky, heavens' and μέτρον (metron) 'measure', literally translates to "measuring the heavens".
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.
Celestial cartography, uranography, astrography or star cartography is the aspect of astronomy and branch of cartography concerned with mapping stars, galaxies, and other astronomical objects on the celestial sphere. Measuring the position and light of charted objects requires a variety of instruments and techniques. These techniques have developed from angle measurements with quadrants and the unaided eye, through sextants combined with lenses for light magnification, up to current methods which include computer-automated space telescopes. Uranographers have historically produced planetary position tables, star tables, and star maps for use by both amateur and professional astronomers. More recently, computerized star maps have been compiled, and automated positioning of telescopes uses databases of stars and of other astronomical objects.
The Dunhuang map or Dunhuang Star map is one of the first known graphical representations of stars from ancient Chinese astronomy, dated to the Tang dynasty (618–907). Before this map, much of the star information mentioned in historical Chinese texts had been questioned. The map provides a graphical verification of the star observations, and are part of a series of pictures on one of the Dunhuang manuscripts. The astronomy behind the map is explained in an educational resource posted on the website of the International Dunhuang Project, where much of the research on the map has been done. The Dunhuang Star map is to date the world's oldest complete preserved star atlas.
The Skalnaté Pleso Atlas of the Heavens is a set of 16 celestial charts covering the entire sky. It is named after the Skalnaté Pleso Observatory in Slovakia where it was produced. The first versions were published by the Czechoslovak Astronomical Society in 1948; later that year, Sky Publishing Corporation acquired the copyright and began publication in the United States. The charts were hand-drawn by Antonín Bečvář.
A Celestial Atlas, full title: A Celestial Atlas: Comprising A Systematic Display of the Heavens in a Series of Thirty Maps Illustrated by Scientific Description of their Contents, And accompanied by Catalogues of the Stars and Astronomical Exercises is a star atlas by British author Alexander Jamieson, published in 1822. The atlas includes 30 plates, 26 of which are constellation maps with a sinusoidal projection. In some editions the plates are hand-colored. The atlas includes three new constellations invented by Jamieson: Noctua, Norma Nilotica, and Solarium. Two celestial hemispheres of the atlas are centered on the equatorial poles via polar projection and geocentric alignment. The atlas comprises stars visible only to the naked eye, making it less cluttered.
The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears to rotate westward around a polar axis as the Earth rotates.
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