Astar chart is acelestial map of thenight sky withastronomical objects laid out on a grid system. They are used to identify and locateconstellations,stars,nebulae,galaxies, andplanets.[1] They have been used for humannavigation since time immemorial.[2] Note that a star chart differs from anastronomical catalog, which is a listing or tabulation of astronomical objects for a particular purpose. Tools using a star chart include theastrolabe andplanisphere.
.jpg)
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 ivoryMammoth 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 constellationOrion, 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 theLascaux caves in France could be a graphical representation of thePleiadesopen 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 theSummer Triangle, which at the time was acircumpolar formation.[4] Rappenglueck also discovered a drawing of theNorthern Crown constellation in thecave 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 theLa Tête du Lion cave (fr). The bovine in this panel may represent the constellationTaurus, with a pattern representing the Pleiades just above it.[6]
A star chart drawn 5000 years ago by theIndians in Kashmir, which also depict a supernova for the first time in human history.[7]TheNebra 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 ancientEgyptian astronomy in 1534 BC.[8] Theearliest known star catalogues were compiled by the ancientBabylonian astronomers ofMesopotamia in the late 2nd millennium BC, during theKassite Period (ca. 1531–1155 BC).[9]The oldest records ofChinese astronomy date to theWarring States period (476–221 BC), but the earliest preserved Chinese star catalogues of astronomersShi Shen andGan De are found in the 2nd-century BCShiji by theWestern Han historianSima Qian.[10] Theoldest Chinese graphical representation of the night sky is alacquerware box from the 5th-century BCTomb of Marquis Yi of Zeng, although this depiction shows the positions of theChinese constellations by name and does not show individual stars.[11]
TheFarnese Atlas is a 2nd-century ADRoman copy of aHellenistic eraGreek statue depicting theTitanAtlas holding thecelestial sphere on his shoulder. It is the oldest surviving depiction of theancient Greek constellations, and includes grid circles that provide coordinate positions. Because ofprecession, 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 theepoch when the original observations were performed. Based upon this information, the constellations were catalogued at125 ± 55 BC. This evidence indicates that thestar catalogue of the 2nd-century BC Greek astronomerHipparchus was used.[12]
ARoman era example of a graphical representation of the night sky is thePtolemaic EgyptianDendera zodiac, dating from 50 BC. This is a bas relief sculpting on a ceiling at theDendera Temple complex. It is aplanisphere depicting thezodiac in graphical representations. However, individual stars are not plotted.[13]
The oldest surviving manuscript star chart was theDunhuang Star Chart, dated to theTang dynasty (618–907) and discovered in theMogao Caves ofDunhuang inGansu,Western China along theSilk Road. This is a scroll 210 cm in length and 24.4 cm wide showing the sky betweendeclinations 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 257asterisms. The date of this chart is uncertain, but is estimated as 705–10 AD.[14][15][16]
During theSong dynasty (960–1279), the Chinese astronomerSu Song wrote a book titledXin 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 astronomerHuang 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 inSuzhou.[15]
InMuslim astronomy, the first star chart to be drawn accurately was most likely the illustrations produced by the Persian astronomerAbd al-Rahman al-Sufi in his 964 work titledBook of Fixed Stars. This book was an update of parts VII.5 and VIII.1 of the 2nd centuryAlmagest star catalogue byPtolemy. 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 theOxford University.[14][15]
Perhaps the oldest European star map was a parchment manuscript titledDe Composicione Spere Solide. It was most likely produced inVienna,Austria in 1440 and consisted of a two-part map depicting the constellations of the northern celestial hemisphere and theecliptic. This may have served as a prototype for the oldest European printed star chart, a 1515 set of woodcut portraits produced byAlbrecht Dürer inNuremberg,Germany.[17]
During the EuropeanAge 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 andFrederick de Houtman, who in 1595 traveled together to theDutch East Indies. Their compilations resulted in the 1601 globe ofJodocus Hondius, who added 12 new southern constellations. Several other such maps were produced, includingJohann Bayer'sUranometria in 1603.[18] The latter was the first atlas to chart both celestial hemispheres and it introduced theBayer designations for identifying the brightest stars using the Greek alphabet. TheUranometria 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 astronomerJohannes 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, includingScutum,Lacerta, andCanes Venatici.
In 1824Sidney Hall produced a set of star charts calledUrania's Mirror. They are illustrations based onAlexander Jamieson'sA 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.
