149-627: Serpens ( Ancient Greek : Ὄφις , romanized : Óphis , lit. 'the Serpent';) is a constellation in the northern celestial hemisphere . One of the 48 constellations listed by the 2nd-century astronomer Ptolemy , it remains one of the 88 modern constellations designated by the International Astronomical Union . It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent Head) to
298-543: A pitch accent . In Modern Greek, all vowels and consonants are short. Many vowels and diphthongs once pronounced distinctly are pronounced as /i/ ( iotacism ). Some of the stops and glides in diphthongs have become fricatives , and the pitch accent has changed to a stress accent . Many of the changes took place in the Koine Greek period. The writing system of Modern Greek, however, does not reflect all pronunciation changes. The examples below represent Attic Greek in
447-567: A star catalogue that includes 90 constellations. The Eastern Han era polymath scientist and inventor Zhang Heng (78–139 CE) published a star catalogue in 120 CE that features 124 recorded constellations. In the late period of the Ming dynasty , the agricultural scientist and mathematician Xu Guangqi (1562–1633 CE) introduced 23 additional constellations near to the Celestial South Pole, which are based on star catalogues from
596-481: A 10-sided polygon, while Serpens Cauda's are defined by a 22-sided polygon. In the equatorial coordinate system , the right ascension coordinates of Serpens Caput's borders lie between 15 10.4 and 16 22.5 , while the declination coordinates are between 25.66° and −03.72°. Serpens Cauda's boundaries lie between right ascensions of 17 16.9 and 18 58.3 and declinations of 06.42° and −16.14°. The International Astronomical Union (IAU) adopted
745-463: A 5.70 day period. The primary star in the system is also a Delta Scuti variable, undergoing multiple pulsation frequencies, which, combined with the eclipses, causes the system to vary by around a tenth of a magnitude. As the galactic plane passes through it, Serpens Cauda contains many massive OB stars . Several of these are visible to the naked eye, such as NW Serpentis , an early Be star that has been found to be somewhat variable. The variability
894-487: A celestial globe (渾象), and a mechanical chronograph. It was operated by an escapement mechanism and the earliest known chain drive . However, 35 years later, the invading Jurchen army dismantled the tower in 1127 CE upon taking the capital of Kaifeng . The armillary sphere part was brought to Beijing , yet the tower was never successfully reinstated, not even by Su Song's son. Fortunately, two versions of Su Song's treatise, written on his clock tower, have survived
1043-472: A cool red giant that pulsates between magnitudes 5.89 and 7.07 in 87 days. This star has been found to display an inverse P Cygni profile , where cold infalling gas on to the star creates redshifted hydrogen absorption lines next to the normal emission lines. Several stars in Serpens have been found to have planets . The brightest, Omega Serpentis , located between Epsilon and Mu, is an orange giant with
1192-407: A distance of 190 million light-years from Earth and is approximately 100,000 light-years across, making Seyfert's Sextet one of the densest galaxy groups known. Astronomers predict that the four interacting galaxies will eventually merge to form a large elliptical galaxy . The radio source 3C 326 was originally thought to emanate from a giant elliptical galaxy. However, in 1990, it was shown that
1341-479: A distinctive triangular shape marking the head of the snake, with Kappa Serpentis (the proper name is Gudja) being roughly midway between Gamma and Iota. The brightest of the four with an apparent magnitude of roughly 3.67, Beta Serpentis is a white main-sequence star roughly 160 parsecs distant. It is likely that a nearby 10th-magnitude star is physically associated with Beta, although it is not certain. The Mira variable R Serpentis , situated between Beta and Gamma,
1490-525: A fifth major dialect group, or it is Mycenaean Greek overlaid by Doric, with a non-Greek native influence. Regarding the speech of the ancient Macedonians diverse theories have been put forward, but the epigraphic activity and the archaeological discoveries in the Greek region of Macedonia during the last decades has brought to light documents, among which the first texts written in Macedonian , such as
1639-405: A planet (we call it) an occultation (hsing wei); when the moon passes across (kuo) (the sun's path) then there is a solar eclipse (shih). The later Song dynasty scientist Shen Kuo (1031–1095 CE) used the models of lunar eclipse and solar eclipse in order to prove that the celestial bodies were round, not flat. This was an extension of the reasoning of Jing Fang and other theorists as early as
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#17327754891991788-398: A planet of at least 1.7 Jupiter -masses. NN Serpentis , an eclipsing post-common-envelope binary consisting of a white dwarf and a red dwarf , is very likely to have two planets causing variations in the period of the eclipses. Although it does not have a planet, the solar analog HD 137510 has been found to have a brown dwarf companion within the brown-dwarf desert . PSR B1534+11
1937-550: A prefix /e-/, called the augment . This was probably originally a separate word, meaning something like "then", added because tenses in PIE had primarily aspectual meaning. The augment is added to the indicative of the aorist, imperfect, and pluperfect, but not to any of the other forms of the aorist (no other forms of the imperfect and pluperfect exist). The two kinds of augment in Greek are syllabic and quantitative. The syllabic augment
2086-445: A sphere is covered with (white) powder and looked at from the side, the covered part will look like a crescent; if looked at from the front, it will appear round. Thus we know that the celestial bodies are spherical. When he asked Shen Kuo why eclipses occurred only on an occasional basis while in conjunction and opposition once a month, Shen Kuo wrote: I answered that the ecliptic and the moon's path are like two rings, lying one over
2235-470: A square shape; and Westerhout 40 , a massive nearby star-forming region consisting of a molecular cloud and an H II region . In Greek mythology , Serpens represents a snake held by the healer Asclepius . Represented in the sky by the constellation Ophiuchus, Asclepius once killed a snake, but the animal was subsequently resurrected after a second snake placed a revival herb on it before its death. As snakes shed their skin every year, they were known as
2384-589: A star map and can present the sky at a specific time. Because of its Chinese name, it is often confused with the armillary sphere, which is just one word different in Chinese (渾象 vs. 渾儀). According to records, the first celestial globe was made by Geng Shou-chang (耿壽昌) between 70 BCE and 50 BCE. In the Ming dynasty , the celestial globe at that time was a huge globe, showing the 28 mansions, celestial equator, and ecliptic. None of them have survived. Celestial globes were named 天體儀 ("Miriam celestial bodies") in
2533-542: A strong Northwest Greek influence, and can in some respects be considered a transitional dialect, as exemplified in the poems of the Boeotian poet Pindar who wrote in Doric with a small Aeolic admixture. Thessalian likewise had come under Northwest Greek influence, though to a lesser degree. Pamphylian Greek , spoken in a small area on the southwestern coast of Anatolia and little preserved in inscriptions, may be either
2682-614: A summary of different astronomical theories in China at the time. In the subsequent period of the Three Kingdoms (220–280 CE), Chen Zhuo (陳卓) combined the work of his predecessors, forming another star catalogue. This time, 283 constellations and 1464 stars were listed. The astronomer Guo Shoujin of the Yuan dynasty (1279–1368 CE) created a new catalogue, which was believed to contain thousands of stars. Unfortunately, many of
2831-708: A terrestrial globe and an armillary sphere , as well as an astronomical almanac , which was later known in China as the Wannian Li ("Ten Thousand Year Calendar" or "Eternal Calendar"). He was known as "Zhama Luding" in China, where, in 1271, he was appointed by the Khan as the first director of the Islamic observatory in Beijing, known as the Islamic Astronomical Bureau, which operated alongside
2980-562: A view to many galaxies beyond it is possible. However, a few structures of the Milky Way Galaxy are present in Serpens Caput, such as Messier 5, a globular cluster positioned approximately 8° southwest of α Serpentis, next to the star 5 Serpentis . Barely visible to the naked eye under good conditions, and is located approximately 25,000 ly distant. Messier 5 contains a large number of known RR Lyrae variable stars, and
3129-510: A vowel or /n s r/ ; final stops were lost, as in γάλα "milk", compared with γάλακτος "of milk" (genitive). Ancient Greek of the classical period also differed in both the inventory and distribution of original PIE phonemes due to numerous sound changes, notably the following: The pronunciation of Ancient Greek was very different from that of Modern Greek . Ancient Greek had long and short vowels ; many diphthongs ; double and single consonants; voiced, voiceless, and aspirated stops ; and
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#17327754891993278-645: A wall surrounding a marketplace, known as Tianshi , which was in Ophiuchus and part of Hercules . Serpens also contains a few Chinese constellations . Two stars in the tail represented part of Shilou , the tower with the market office. Another star in the tail represented Liesi , jewel shops. One star in the head ( Mu Serpentis ) marked Tianru , the crown prince 's wet nurse, or sometimes rain . There were two "serpent" constellations in Babylonian astronomy , known as Mušḫuššu and Bašmu. It appears that Mušḫuššu
3427-572: A wider sighting tube that could be fixed to observe the pole star indefinitely. Along with the pole star, Shen Kuo and Wei Pu also established a project of nightly astronomical observation over a period of five successive years, an intensive work that would even rival the later work of Tycho Brahe in Europe. Shen Kuo and Wei Pu charted the exact coordinates of the planets on a star map for this project and created theories of planetary motion, including retrograde motion . Buddhism first reached China during
3576-453: Is NRAO 530 , a blazar that has been known to flare in the X-rays occasionally. One of these flares was for less than 2000 seconds, making it the shortest flare ever observed in a blazar as of 2004. The blazar also appears to show periodic variability in its radio wave output over two different periods of six and ten years. There are two daytime meteor showers that radiate from Serpens,
3725-464: Is a chemically peculiar star. The two stars in Serpens Caput that form part of the Snake's body below the heart are Epsilon and Mu Serpentis, both third-magnitude A-type main-sequence stars . Both have a peculiarity: Epsilon is an Am star , while Mu is a binary. Located slightly northwest of Mu is 36 Serpentis , another A-type main-sequence star. This star also has a peculiarity; it is a binary with
3874-414: Is a dark nebula complex that, along with a third cloud, is likely formed by fragments of a single original cloud located 36 degrees away from the galactic plane, a large distance for dark nebulae. The entire complex is thought to be around 140 parsecs distant. L183, also referred to as L134N, is home to several infrared sources, indicating pre-stellar sources thought to present the first known observation of
4023-402: Is a slowly pulsating B star , which causes the system to vary by 0.03 magnitudes. Serpens Caput contains many RR Lyrae variables , although most are too faint to be seen without professional photography. The brightest is VY Serpentis , only of 10th magnitude. This star's period has been increasing by approximately 1.2 seconds per century. A variable star of a different kind is Tau Serpentis ,
4172-475: Is a member of the very rare class of galaxies known as ring galaxies. The outer ring is largely composed of young blue stars while the core is made up of older yellow stars. The predominant theory regarding its formation is that the progenitor galaxy was a barred spiral galaxy whose arms had velocities too great to keep the galaxy's coherence and therefore detached. Arp 220 is another unusual galaxy in Serpens. The prototypical ultraluminous infrared galaxy , Arp 220
4321-557: Is a single star with a 9th-magnitude visual companion, while Omicron is a Delta Scuti variable with amplitude variations of 0.01 magnitudes. In 1909, the symbiotic nova RT Serpentis appeared near Omicron, although it only reached a maximum magnitude of 10. The star system 59 Serpentis , also known as d Serpentis, is a triple star system consisting of a spectroscopic binary containing an A-type star and an orange giant and an orange giant secondary. The system shows irregular variations in brightness between magnitudes 5.17 and 5.2. In 1970,
4470-423: Is a system consisting of two neutron stars orbiting each other, one of which is a pulsar with a period of 37.9 milliseconds. Situated approximately 1000 parsecs distant, the system was used to test Albert Einstein 's theory of general relativity , validating the system's relativistic parameters to within 0.2% of values predicted by the theory. The X-ray emission from the system has been found to be present when
4619-493: Is a tiny and difficult double-double star at 18:45 / +5°30', named Tweedledee and Tweedledum by South African astronomer William Stephen Finsen , who was struck by the nearly identical position angles and separations at the time of his 1953 discovery. Gliese 710 is a star that is expected to pass very close to the Solar System in around 1.29 million years. As the galactic plane does not pass through this part of Serpens,
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4768-418: Is added to stems beginning with consonants, and simply prefixes e (stems beginning with r , however, add er ). The quantitative augment is added to stems beginning with vowels, and involves lengthening the vowel: Some verbs augment irregularly; the most common variation is e → ei . The irregularity can be explained diachronically by the loss of s between vowels, or that of the letter w , which affected
4917-481: Is also unusual in that it depends on another constellation for context; specifically, it is being held by the Serpent Bearer Ophiuchus. Serpens Caput is bordered by Libra to the south, Virgo and Boötes to the west, Corona Borealis to the north, and Ophiuchus and Hercules to the east; Serpens Cauda is bordered by Sagittarius to the south, Scutum and Aquila to the east, and Ophiuchus to
5066-448: Is considered by some linguists to have been closely related to Greek . Among Indo-European branches with living descendants, Greek is often argued to have the closest genetic ties with Armenian (see also Graeco-Armenian ) and Indo-Iranian languages (see Graeco-Aryan ). Ancient Greek differs from Proto-Indo-European (PIE) and other Indo-European languages in certain ways. In phonotactics , ancient Greek words could end only in
5215-449: Is due to (the light of) the sun being obstructed (pi). The side which faces the sun is fully lit, and the side which is away from it is dark. The planets (as well as the moon) have the nature of water and reflect light. The light pouring forth from the sun (tang jih chih chhung kuang) does not always reach the moon, owing to the obstruction (pi) of the earth itself—this is called 'an-hsü', a lunar eclipse . When (a similar effect) happens with
5364-720: Is from Su Song 's (1020–1101 CE) celestial atlas of 1092 CE, which was included in the horological treatise on his clocktower . The most famous one is perhaps the Dunhuang map found in Dunhuang , Gansu . Uncovered by the British archaeologist Marc Aurel Stein in 1907, the star map was brought to the British Museum in London . The map was drawn on paper and represents the complete sky, with more than 1,350 stars. Although ancient Babylonians and Greeks also observed
5513-490: Is in orbit around the red giant star, although it is not visible to the naked eye. Situated near Alpha is Lambda Serpentis , a magnitude 4.42 ± 0.05 star rather similar to the Sun positioned only 12 parsecs away. It has an exoplanet orbiting around it. Another solar analog in Serpens is the primary of Psi Serpentis , a binary star located slightly further away at approximately 14 parsecs. Beta , Gamma , and Iota Serpentis form
5662-401: Is interesting; according to one study, it could be one of the first discovered hybrids between Beta Cephei variables and slowly pulsating B stars. Although not visible to the naked eye, HD 167971 (MY Serpentis) is a Beta Lyrae variable triple system consisting of three very hot O-type stars . A member of the cluster NGC 6604 , the two eclipsing stars are both blue giants, with one being of
5811-462: Is near the Eddington limit . The system has also been found to approximately every 3 days brighten by around 3.5 K-band magnitudes, possibly due to the presence of a synchrotron jet . Another low-mass X-ray binary, Serpens X-1 , undergoes occasional X-ray bursts. One in particular lasted nearly four hours, possibly explained by the burning of carbon in "a heavy element ocean". Φ 332 (Finsen 332)
5960-675: Is not as well-studied as others. The embedded cluster likely contains over 600 stars above 0.1 solar masses, with several massive stars, including at least one O-type star, being responsible for lighting the HII region and the production of a bubble . Despite the presence of the Milky Way, several active galaxies are visible in Serpens Cauda as well, such as PDS 456 , found near Xi Serpentis. The most intrinsically luminous nearby active galaxy, this AGN has been found to be extremely variable in
6109-403: Is only visible in infrared light. The Serpens cloud is a massive star-forming molecular cloud situated in the southern part of Serpens Cauda. Only two million years old and 420 parsecs distant, the cloud is known to contain many protostars such as Serpens FIRS 1 and Serpens SVS 20 . The Serpens South protocluster was uncovered by NASA's Spitzer Space Telescope in the southern portion of
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6258-408: Is parallel with the equatorial plane and is accordingly called "equatorial ring", and the other is a double ring that is perpendicular to the center of the equatorial ring, revolving around a metallic shaft, and is called "right ascension double ring". The double ring holds within itself a sighting tube with crosshairs. When observing, astronomers would aim at the star with the sighting tube, whereupon
6407-491: Is receding from us at over 50 km/s. The cluster contains two millisecond pulsars , one of which is in a binary, allowing the proper motion of the cluster to be measured. The binary could help our understanding of neutron degenerate matter ; the current median mass, if confirmed, would exclude any "soft" equation of state for such matter. The cluster has been used to test for magnetic dipole moments in neutrinos, which could shed light on some hypothetical particles such as
6556-476: Is somewhat closer than Hoag's Object at 250 million light-years from Earth. It consists of two large spiral galaxies in the process of colliding with their nuclei orbiting at a distance of 1,200 light-years, causing extensive star formation throughout both components. It possesses a large cluster of more than a billion stars, partially covered by thick dust clouds near one of the galaxies' core. Another interacting galaxy pair, albeit in an earlier stage, consists of
6705-541: Is suspected that such Serpentids are in an earlier evolutionary phase, and will evolve first into double periodic variables and then classical Algol variables. Also near the Eagle Nebula is the eclipsing Wolf–Rayet binary CV Serpentis , consisting of a Wolf–Rayet star and a hot O-type subgiant. The system is surrounded by a ring-shaped nebula , likely formed during the Wolf–Rayet phase of the primary. The eclipses of
6854-449: Is ten times higher than the Sun for most metals at the iron peak and up to 1,000 times more for heavier elements. It has also been found to contain excess silicon . Barely visible to the naked eye is HD 172365 , a likely post- blue straggler in the open cluster IC 4756 that contains a large excess of lithium . HD 172189 , also located in IC 4756, is an Algol variable eclipsing binary with
7003-553: Is the only known spectroscopic binary to consist of a star with excess of mercury and manganese and an Ap star. South of the Eagle Nebula on the border with Sagittarius is the eclipsing binary W Serpentis , whose primary is a white giant that is interacting with the secondary. The system has been found to contain an accretion disk , and was one of the first discovered Serpentids , which are eclipsing binaries containing exceptionally strong far-ultraviolet spectral lines. It
7152-615: Is therefore rich in galactic deep-sky objects , such as the Eagle Nebula (IC 4703) and its associated star cluster Messier 16 . The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation , three dust clouds that became famous for the image taken by the Hubble Space Telescope . Other striking objects include the Red Square Nebula , one of the few objects in astronomy to take on
7301-406: Is visible to the naked eye at its maximum of 5th-magnitude, but, typical of Mira variables, it can fade to below magnitude 14. Gamma Serpentis itself is an F-type subgiant located only 11 parsecs distant and thus is quite bright, being of magnitude 3.84 ± 0.05. The star is known to show solar-like oscillations . Iota Serpentis is a binary star system. Delta Serpentis , forming part of the body of
7450-512: The 28 mansions . In 1977, a lacquer box was excavated from the Tomb of Marquis Yi of Zeng , in Suixian, Hubei Province. Names of the 28 lunar mansions were found on the cover of the box, proving that the use of this classification system was made before 433 BCE. As lunar mansions have such an ancient origin, the meanings of most of their names have become obscure. Contributing to later confusion,
7599-679: The Archaic or Epic period ( c. 800–500 BC ), and the Classical period ( c. 500–300 BC ). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers . It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance . This article primarily contains information about
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#17327754891997748-500: The BL Lac object PG 1553+113 is a heavy emitter of gamma rays . This object is the most distant found to emit photons with energies in the TeV range as of 2007. The spectrum is unique, with hard emission in some ranges of the gamma-ray spectrum in stark contrast to soft emission in others. In 2012, the object flared in the gamma-ray spectrum, tripling in luminosity for two nights, allowing
7897-530: The Crab Nebula , now known as SN 1054 , is an example of an astronomical event observed by Ancient Chinese astronomers. Ancient astronomical records of phenomena like comets and supernovae are sometimes used in modern astronomical studies. The Chinese developed multiple cosmological models before Western influences changed the field: The divisions of the sky began with the Northern Dipper and
8046-606: The Epic and Classical periods of the language, which are the best-attested periods and considered most typical of Ancient Greek. From the Hellenistic period ( c. 300 BC ), Ancient Greek was followed by Koine Greek , which is regarded as a separate historical stage, though its earliest form closely resembles Attic Greek , and its latest form approaches Medieval Greek . There were several regional dialects of Ancient Greek; Attic Greek developed into Koine. Ancient Greek
8195-622: The Omega Serpentids and the Sigma Serpentids . Both showers peak between December 18 and December 25. Ancient Greek language Ancient Greek ( Ἑλληνῐκή , Hellēnikḗ ; [hellɛːnikɛ́ː] ) includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek ( c. 1400–1200 BC ), Dark Ages ( c. 1200–800 BC ),
8344-501: The Pella curse tablet , as Hatzopoulos and other scholars note. Based on the conclusions drawn by several studies and findings such as Pella curse tablet , Emilio Crespo and other scholars suggest that ancient Macedonian was a Northwest Doric dialect , which shares isoglosses with its neighboring Thessalian dialects spoken in northeastern Thessaly . Some have also suggested an Aeolic Greek classification. The Lesbian dialect
8493-554: The Qing dynasty . The one in Beijing Ancient Observatory was made by Belgian missionary Ferdinand Verbiest (南懷仁) in 1673 CE. Unlike other Chinese celestial globes, it employs 360 degrees rather than the 365.24 degrees (which is a standard in ancient China). It is also the first Chinese globe that shows constellations near to the Celestial South Pole. The inventor of the hydraulic -powered armillary sphere
8642-494: The Red Rectangle Nebula , the planetary nebula appears to be a nearly perfect square with a dark band around the equatorial regions. The nebula contains concentric rings, which are similar to those seen in the supernova SN 1987A . MWC 922 itself is an FS Canis Majoris variable , meaning that it is a Be star containing exceptionally bright hydrogen emission lines as well as select forbidden lines , likely due to
8791-612: The Shang dynasty , the era in which it was supposed to have been written. Moreover, it was customary in the past for the Chinese to forge works of notable scholars, as this could lead to a possible explanation for the inconsistencies found. Wu Xian is generally mentioned as the astronomer who lived many years before Gan and Shi. The Han dynasty astronomer and inventor Zhang Heng (78–139 CE) not only catalogued some 2500 different stars, but also recognized more than 100 different constellations. Zhang Heng also published his work Ling Xian ,
8940-533: The Song dynasty , when a Hui Muslim astronomer named Ma Yize introduced the concept of 7 days in a week and made other contributions. Islamic astronomers were brought to China in order to work on calendar-making and astronomy during the Mongol Empire and the succeeding Yuan dynasty . The Chinese scholar Yelü Chucai accompanied Genghis Khan to Persia in 1210 and studied their calendar for use in
9089-492: The X-ray spectrum . This has allowed light to be shed on the nature of the supermassive black hole at the center, likely a Kerr black hole . It is possible that the quasar is undergoing a transition from an ultraluminous infrared galaxy to a classical radio-quiet quasar, but there are problems with this theory, and the object appears to be an exceptional object that does not completely lie within current classification systems. Nearby
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#17327754891999238-491: The armillary sphere in China goes back to the 1st century BCE, as they were equipped with a primitive single-ring armillary instrument. This would have allowed them to measure the north polar distance (去極度, the Chinese form of declination) and measurement that gave the position in a hsiu (入宿度, the Chinese form of right ascension). During the Western Han dynasty (202 BCE–9 CE), additional developments made by
9387-516: The axion . The brightest stars in Messier 5 are around magnitude 10.6, and the globular cluster was first observed by William Herschel in 1791. Another globular cluster is Palomar 5 , found just south of Messier 5. Many stars are leaving this globular cluster due to the Milky Way's gravity, forming a tidal tail over 30000 light-years long. It is over 11 billion years old. It has also been flattened and distorted by tidal effects. The L134 / L183
9536-603: The epic poems , the Iliad and the Odyssey , and in later poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic and other Classical-era dialects. The origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between
9685-501: The present , future , and imperfect are imperfective in aspect; the aorist , present perfect , pluperfect and future perfect are perfective in aspect. Most tenses display all four moods and three voices, although there is no future subjunctive or imperative. Also, there is no imperfect subjunctive, optative or imperative. The infinitives and participles correspond to the finite combinations of tense, aspect, and voice. The indicative of past tenses adds (conceptually, at least)
9834-560: 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" (宿 xiù ) system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE). They flourished during the Han period (202 BCE – 220 CE) and subsequent dynasties with
9983-618: The "simplified instrument" ( jianyi ) and the large gnomon at the Gaocheng Astronomical Observatory show traces of Islamic influence. While formulating the Shoushili calendar in 1281, Shoujing's work in spherical trigonometry may have also been partially influenced by Islamic mathematics , which was largely accepted at Kublai's court. These possible influences include a pseudo-geometrical method for converting between equatorial and ecliptic coordinates ,
10132-1031: The 5th century BC. Ancient pronunciation cannot be reconstructed with certainty, but Greek from the period is well documented, and there is little disagreement among linguists as to the general nature of the sounds that the letters represent. /oː/ raised to [uː] , probably by the 4th century BC. Greek, like all of the older Indo-European languages , is highly inflected. It is highly archaic in its preservation of Proto-Indo-European forms. In ancient Greek, nouns (including proper nouns) have five cases ( nominative , genitive , dative , accusative , and vocative ), three genders ( masculine , feminine , and neuter ), and three numbers (singular, dual , and plural ). Verbs have four moods ( indicative , imperative , subjunctive , and optative ) and three voices (active, middle, and passive ), as well as three persons (first, second, and third) and various other forms. Verbs are conjugated through seven combinations of tenses and aspect (generally simply called "tenses"):
10281-495: The Archaic period of ancient Greek (see Homeric Greek for more details): Μῆνιν ἄειδε, θεά, Πηληϊάδεω Ἀχιλῆος οὐλομένην, ἣ μυρί' Ἀχαιοῖς ἄλγε' ἔθηκε, πολλὰς δ' ἰφθίμους ψυχὰς Ἄϊδι προΐαψεν ἡρώων, αὐτοὺς δὲ ἑλώρια τεῦχε κύνεσσιν οἰωνοῖσί τε πᾶσι· Διὸς δ' ἐτελείετο βουλή· ἐξ οὗ δὴ τὰ πρῶτα διαστήτην ἐρίσαντε Ἀτρεΐδης τε ἄναξ ἀνδρῶν καὶ δῖος Ἀχιλλεύς. The beginning of Apology by Plato exemplifies Attic Greek from
10430-516: The Chinese Astronomical Bureau for four centuries. Islamic astronomy gained a good reputation in China for its theory of planetary latitudes , which did not exist in Chinese astronomy at the time, and for its accurate prediction of eclipses. Some of the astronomical instruments constructed by the famous Chinese astronomer Guo Shoujing shortly afterwards resemble the style of instrumentation built at Maragheh. In particular,
10579-741: The Classical period of ancient Greek. (The second line is the IPA , the third is transliterated into the Latin alphabet using a modern version of the Erasmian scheme .) Ὅτι [hóti Hóti μὲν men mèn ὑμεῖς, hyːmêːs hūmeîs, Chinese astronomy 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
10728-545: The Dorians. The Greeks of this period believed there were three major divisions of all Greek people – Dorians, Aeolians, and Ionians (including Athenians), each with their own defining and distinctive dialects. Allowing for their oversight of Arcadian, an obscure mountain dialect, and Cypriot, far from the center of Greek scholarship, this division of people and language is quite similar to the results of modern archaeological-linguistic investigation. One standard formulation for
10877-524: The Eastern Han dynasty, and translation of Indian works on astronomy came to China by the Three Kingdoms era (220–265 CE). However, the most detailed incorporation of Indian astronomy occurred only during the Tang dynasty (618–907), when a number of Chinese scholars—such as Yi Xing —were versed in both types of astronomy. A system of Indian astronomy was recorded in China as Jiuzhi-li (718 CE),
11026-518: The GRB has also been much fainter than for other dimmer GRBs. More distant is GRB 060526 (redshift z = 3.221), from which X-ray and optical afterglows were detected. This GRB was very faint for a long-duration GRB. Part of the galactic plane passes through the tail, and thus Serpens Cauda is rich in deep-sky objects within the Milky Way galaxy. The Eagle Nebula and its associated star cluster, Messier 16 lie around 5,700 light-years from Earth in
11175-648: The Han dynasty. In his Dream Pool Essays of 1088 CE, Shen related a conversation he had with the director of the Astronomical Observatory , who had asked Shen if the shapes of the Sun and the Moon were round like balls or flat like fans. Shen Kuo explained his reasoning for the former: If they were like balls they would surely obstruct each other when they met. I replied that these celestial bodies were certainly like balls. How do we know this? By
11324-576: The Indian system. Islamic astronomers collaborated closely with their Chinese colleagues during the Yuan dynasty , and, after a period of relative decline during the Ming dynasty , astronomy was revitalized under the stimulus of Western cosmology and technology after the Jesuits established their missions. The telescope was introduced from Europe in the seventeenth century. In 1669, the Peking observatory
11473-437: The Milky Way in Serpens Cauda, one globular cluster can be found: NGC 6535 , although invisible to the naked eye, can be made out in small telescopes just north of Zeta Serpentis. Rather small and sparse for a globular cluster, this cluster contains no known RR Lyrae variables, which is unusual for a globular cluster. MWC 922 is a star surrounded by a planetary nebula . Dubbed the Red Square Nebula due to its similarities to
11622-761: The Mongol Empire. Kublai Khan brought Iranians to Beijing to construct an observatory and an institution for astronomical studies. Several Chinese astronomers worked at the Maragheh observatory , founded by Nasir al-Din al-Tusi in 1259 under the patronage of Hulagu Khan in Persia. One of these Chinese astronomers was Fu Mengchi, or Fu Mezhai. In 1267, the Persian astronomer Jamal ad-Din , who previously worked at Maragha observatory, presented Kublai Khan with seven Persian astronomical instruments , including
11771-451: The Moon and the Sun. The radiating-influence theory, where the Moon's light was nothing but a reflection of the Sun's, was supported by the mathematician and music theorist Jing Fang (78–37 BCE), yet opposed by the Chinese philosopher Wang Chong (27–97 CE), who made clear in his writing that this theory was nothing new. Jing Fang wrote: The moon and the planets are Yin ; they have shape but no light. This they receive only when
11920-414: The Moon shining because of reflected light. The Chinese astronomer and inventor Zhang Heng (78–139 CE) wrote of both solar eclipse and lunar eclipse in the publication of Ling Xian (靈憲), 120 CE: The sun is like fire and the moon like water. The fire gives out light and the water reflects it. Thus, the moon's brightness is produced from the radiance of the sun, and the moon's darkness (pho)
12069-618: The Western world introduced by his colleague, the Italian Jesuit Matteo Ricci . In the fourth century BCE, the two Chinese astronomers responsible for the earliest information going into the star catalogues were Shi Shen and Gan De of the Warring States period . These books appeared to have lasted until the sixth century, but were lost after that. A number of books share similar names, often quoted and named after them. These texts should not be confused with
12218-501: The ages, so that studying his astronomical clock tower is made possible through medieval texts. The polymath Chinese scientist Shen Kuo (1031–1095 CE) was not only the first in history to describe the magnetic -needle compass , but also made a more accurate measurement of the distance between the pole star and true north that could be used for navigation . Shen achieved this by making nightly astronomical observations, along with his colleague Wei Pu , using Shen's improved design of
12367-550: The aorist. Following Homer 's practice, the augment is sometimes not made in poetry , especially epic poetry. The augment sometimes substitutes for reduplication; see below. Almost all forms of the perfect, pluperfect, and future perfect reduplicate the initial syllable of the verb stem. (A few irregular forms of perfect do not reduplicate, whereas a handful of irregular aorists reduplicate.) The three types of reduplication are: Irregular duplication can be understood diachronically. For example, lambanō (root lab ) has
12516-459: The association appears to still contain star-forming regions, and the light from its stars is illuminating the HII region S 54 . Within this HII region is the open cluster NGC 6604 , which is the same age as the surrounding OB association, and the cluster is now thought to simply be the densest part of it. The cluster appears to be producing a thermal chimney of ionized gas, caused by the interaction of
12665-402: The asterism crosses over to Mu Serpentis in the head, is a triple star system located approximately 105 parsecs away. Two of the stars, with a combined apparent magnitude of around 3.5, form a spectroscopic binary with an angular separation of only 2.2 milli arcseconds , and thus cannot be resolved with modern equipment. The primary is a white giant with an excess of strontium . Theta, forming
12814-427: The astronomers Luoxia Hong (落下閎), Xianyu Wangren (鮮于妄人) , and Geng Shouchang (耿壽昌) advanced the use of the armillary in its early stage of evolution. In 52 BCE, it was the astronomer Geng Shou-chang who introduced the fixed equatorial ring to the armillary sphere. In the subsequent Eastern Han dynasty (23–220 CE) period, the astronomers Fu An and Jia Kui added the elliptical ring by 84 CE. With
12963-419: The augment when it was word-initial. In verbs with a preposition as a prefix, the augment is placed not at the start of the word, but between the preposition and the original verb. For example, προσ(-)βάλλω (I attack) goes to προσ έ βαλoν in the aorist. However compound verbs consisting of a prefix that is not a preposition retain the augment at the start of the word: αὐτο(-)μολῶ goes to ηὐ τομόλησα in
13112-681: The author of which was an Indian by the name of Qutan Xida . The astronomical table of sines by the Indian astronomer and mathematician Aryabhata was translated into the Chinese astronomical and mathematical book Treatise on Astrology of the Kaiyuan Era ( Kaiyuan Zhanjing ), compiled in 718 CE, during the Tang dynasty . The Kaiyuan Zhanjing was compiled by Gautama Siddha , an astronomer and astrologer born in Chang'an , and whose family
13261-479: The cloud, and it appears that star formation is still continuing in the region. Another site of star formation is the Westerhout 40 complex, consisting of a prominent HII region adjacent to a molecular cloud. Located around 500 parsecs distant, it is one of the nearest massive regions of star formation, but as the molecular cloud obscures the HII region, rendering it and its embedded cluster tough to see visibly, it
13410-420: The cluster Abell 2052 has central cD radio galaxy, 3C 317 . This radio galaxy is believed to have restarted after a period of inactivity less than 200 years ago. The galaxy has over 40,000 known globular clusters, the highest known total of any galaxy as of 2002. Consisting of two quasars with a separation of less than 5 arcseconds , the quasar pair 4C 11.50 is one of the visually closest pairs of quasars in
13559-414: The constellations Serpens and Ophiuchus were depicted as two separate constellations, although more often they were shown as a single constellation. One notable figure to depict Serpens separately was Johann Bayer ; thus, Serpens' stars are cataloged with separate Bayer designations from those of Ophiuchus. When Eugène Delporte established modern constellation boundaries in the 1920s, he elected to depict
13708-458: The contraction phase between cloud cores and prestellar cores. The core is split into three regions, with a combined mass of around 25 solar masses. Outside of the Milky Way, there are no bright deep-sky objects for amateur astronomers in Serpens Caput, with nothing else above 10th magnitude. The brightest is NGC 5962 , a spiral galaxy positioned around 28 megaparsecs distant with an apparent magnitude of 11.34. Two supernovae have been observed in
13857-615: The dialect of Sparta ), and Northern Peloponnesus Doric (including Corinthian ). All the groups were represented by colonies beyond Greece proper as well, and these colonies generally developed local characteristics, often under the influence of settlers or neighbors speaking different Greek dialects. After the conquests of Alexander the Great in the late 4th century BC, a new international dialect known as Koine or Common Greek developed, largely based on Attic Greek , but with influence from other dialects. This dialect slowly replaced most of
14006-530: The dialects is: West vs. non-West Greek is the strongest-marked and earliest division, with non-West in subsets of Ionic-Attic (or Attic-Ionic) and Aeolic vs. Arcadocypriot, or Aeolic and Arcado-Cypriot vs. Ionic-Attic. Often non-West is called 'East Greek'. Arcadocypriot apparently descended more closely from the Mycenaean Greek of the Bronze Age. Boeotian Greek had come under
14155-561: The direction of the Galactic Center . The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation, three dust clouds that became famous for the image taken by the Hubble Space Telescope . The stars being born in the Eagle Nebula, added to those with an approximate age of 5 million years have an average temperature of 45,000 kelvins and produce prodigious amounts of radiation that will eventually destroy
14304-510: The divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period. They have the same general outline but differ in some of the detail. The only attested dialect from this period is Mycenaean Greek , but its relationship to the historical dialects and the historical circumstances of the times imply that the overall groups already existed in some form. Scholars assume that major Ancient Greek period dialect groups developed not later than 1120 BC, at
14453-411: The documents of that period were destroyed, including that of Shoujin. Imperial Astronomical Instruments (儀象考成) was published in 1757 and contains 3083 stars exactly. The Chinese drew many maps of stars in the past centuries. It is debatable as to which counts as the oldest star maps, since pottery and old artifacts can also be considered star maps. One of the oldest existent star maps in printed form
14602-465: The dust pillars. Despite its fame, the Eagle Nebula is fairly dim, with an integrated magnitude of approximately 6.0. The star-forming regions in the nebula are often evaporating gaseous globules ; unlike Bok globules they only hold one protostar . North of Messier 16, at a distance of approximately 2000 parsecs, is the OB association Serpens OB2 , containing over 100 OB stars. Around 5 million years old,
14751-638: The famous statesman, astronomer, and inventor Zhang Heng (78–139 CE), the sphere was totally completed in 125 CE, with horizon and meridian rings. It is of great importance to note that the world's first hydraulic (i.e., water-powered) armillary sphere was created by Zhang Heng, who operated his by use of an inflow clepsydra clock (see Zhang's article for more detail). Designed by famous astronomer Guo Shoujing in 1276 CE, it solved most problems found in armillary spheres at that time. The primary structure of abridged armilla contains two large rings that are perpendicular to each other, of which one
14900-462: The galaxies NGC 5953 and NGC 5954 . In this case, both are active galaxies , with the former a Seyfert 2 galaxy and the latter a LINER-type galaxy. Both are undergoing a burst of star formation triggered by the interaction. Seyfert's Sextet is a group of six galaxies, four of which are interacting gravitationally and two of which simply appear to be a part of the group despite their greater distance. The gravitationally bound cluster lies at
15049-477: The galaxy, and NGC 5962 has two satellite galaxies. Slightly fainter is NGC 5921 , a barred spiral galaxy with a LINER -type active galactic nucleus situated somewhat closer at a distance of 21 megaparsecs. A type II supernova was observed in this galaxy in 2001 and was designated SN 2001X. Fainter still are the spirals NGC 5964 and NGC 6118 , with the latter being host to the supernova SN 2004dk . Hoag's Object, located 600 million light-years from Earth,
15198-406: The gas from the galactic disk with the galactic halo . Another open cluster in Serpens Cauda is IC 4756 , containing at least one naked-eye star, HD 172365 (another naked-eye star in the vicinity, HD 171586 , is most likely unrelated). Positioned approximately 440 parsecs distant, the cluster is estimated to be around 800 million years old, quite old for an open cluster. Despite the presence of
15347-615: The instrument to China. In 1933, it was placed in Purple Mountain Observatory , which prevented it from being destroyed in the Japanese invasion of China . In the 1980s, it had become seriously eroded and rusted down and was nearly destroyed. In order to restore the device, the Nanjing government spent 11 months to repair it. Besides star maps, the Chinese also made celestial globes, which show stars' positions like
15496-414: The movement of the sun along the sky each month, which was not based on the observation at that time. Chinese astronomers recorded 1,600 observations of solar and lunar eclipses from 750 BCE. The ancient Chinese astronomer Shi Shen (fl. fourth century BCE) was aware of the relation of the Moon in a solar eclipse, as he provided instructions in his writing to predict them by using the relative positions of
15645-447: The naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau Serpentis . Notable extragalactic objects include Seyfert's Sextet , one of the densest galaxy clusters known; Arp 220 , the prototypical ultraluminous infrared galaxy ; and Hoag's Object , the most famous of the very rare class of galaxies known as ring galaxies . Part of the Milky Way's galactic plane passes through Serpens Cauda, which
15794-463: The name of each lunar mansion consists of only one Chinese word, the meaning of which could vary at different times in history. The meanings of the names are still under discussion. Besides the 28 lunar mansions, most constellations are based on the works of Shi Shen-fu and Gan De , who were astrologists during the period of the Warring States (481–221 BCE) in China. In his Shiji , the Western Han era historian Sima Qian (145–86 BCE) provided
15943-632: The newly established national observatory. That year, the Ming government summoned, for the first time, the astronomical officials to come south from the upper capital of Yuan. There were fourteen of them. In order to enhance accuracy in methods of observation and computation, Emperor Taizu reinforced the adoption of parallel calendar systems, the Han and the Hui . In the following years, the Ming Court appointed several Hui astrologers to hold high positions in
16092-399: The night sky and likely in actual space at an estimated distance of around 70 parsecs, is the barium star 16 Serpentis . Another notable variable star visible to the naked eye is Chi Serpentis , an Alpha² Canum Venaticorum variable situated midway between Delta and Beta which varies from its median brightness of 5.33 by 0.03 magnitudes over a period of approximately 1.5 days. Chi Serpentis
16241-474: The non-pulsar star intersects the equatorial pulsar wind of the pulsar, and the system's orbit has been found to vary slightly. The brightest star in the tail, Eta Serpentis , is similar to Alpha Serpentis' primary in that it is a red giant of spectral class K. This star, however, is known to exhibit solar-like oscillations over a period of approximately 2.16 hours. The other two stars in Serpens Cauda forming its asterism are Theta and Xi Serpentis . Xi, where
16390-528: The north and west. Covering 636.9 square degrees total, it ranks 23rd of the 88 constellations in size. It appears prominently in both the northern and southern skies during the Northern Hemisphere's summer. Its main asterism consists of 11 stars, and 108 stars in total are brighter than magnitude 6.5, the traditional limit for naked-eye visibility. Serpens Caput's boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by
16539-547: The nova FH Serpentis appeared just slightly north of 59 Serpentis, reaching a maximum brightness of 4.5. Also near 59 Serpentis in the Serpens Cloud are several Orion variables . MWC 297 is a Herbig Be star that in 1994 exhibited a large X-ray flare and increased in X-ray luminosity by five times before returning to the quiescent state. The star also appears to possess a circumstellar disk . Another Orion variable in
16688-508: The older dialects, although the Doric dialect has survived in the Tsakonian language , which is spoken in the region of modern Sparta. Doric has also passed down its aorist terminations into most verbs of Demotic Greek . By about the 6th century AD, the Koine had slowly metamorphosed into Medieval Greek . Phrygian is an extinct Indo-European language of West and Central Anatolia , which
16837-436: The original catalogues written by them. Notable works that helped preserve the contents include: Wu Xian (巫咸) has been one of the astronomers under debate. He is often represented as one of the "Three Schools Astronomical tradition", along with Gan and Shi. The Chinese classic text Star Manual of Master Wu Xian (巫咸星經) and its authorship is still in dispute, because it mentioned names of twelve countries that did not exist in
16986-409: The other end of the stellar age spectrum is L483 , a dark nebula which contains the protostar IRAS 18418-0440 . Although classified as a class 0 protostar , it has some unusual features for such an object, such as a lack of high-velocity stellar winds , and it has been proposed that this object is in transition between class 0 and class I . A variable nebula exists around the protostar, although it
17135-419: The other, but distant by a small amount. (If this obliquity did not exist), the sun would be eclipsed whenever the two bodies were in conjunction, and the moon would be eclipsed whenever they were exactly in opposition. But (in fact) though they may occupy the same degree, the two paths are not (always) near (each other), and so naturally, the bodies do not (intrude) upon one another. The earliest development of
17284-487: The perfect stem eilēpha (not * lelēpha ) because it was originally slambanō , with perfect seslēpha , becoming eilēpha through compensatory lengthening. Reduplication is also visible in the present tense stems of certain verbs. These stems add a syllable consisting of the root's initial consonant followed by i . A nasal stop appears after the reduplication in some verbs. The earliest extant examples of ancient Greek writing ( c. 1450 BC ) are in
17433-430: The positioning of the cD galaxy at the center of Abell 2063. The active galaxy at the center of MKW 3s— NGC 5920 —appears to be creating a bubble of hot gas from its radio activity. Near the 5th-magnitude star Pi Serpentis lies AWM 4 , a cluster containing an excess of metals in the intracluster medium. The central galaxy, NGC 6051 , is a radio galaxy that is probably responsible for this enrichment. Similar to AWM 4,
17582-407: The presence of a close binary. East of Xi Serpentis is another planetary nebula, Abell 41 , containing the binary star MT Serpentis at its center. The nebula appears to have a bipolar structure, and the axis of symmetry of the nebula has been found to be within 5° of the line perpendicular to the orbital plane of the stars, strengthening the link between binary stars and bipolar planetary nebulae. On
17731-427: The primary component being a Lambda Boötis star , meaning that it has solar-like amounts of carbon , nitrogen , and oxygen , while containing very low amounts of iron peak elements. The secondary star has also been a source of X-ray emissions. 25 Serpentis , positioned a few degrees northeast of Mu Serpentis, is a spectroscopic binary consisting of a hot B-type giant and an A-type main-sequence star. The primary
17880-414: The process of merging. Both members appear to be active galaxies; the primary radio galaxy may be responsible for the activity in the secondary by means of the former's jet driving material onto the latter's supermassive black hole . An example of gravitational lensing is found in the radio galaxy 3C 324 . First thought to be a single overluminous radio galaxy with a redshift of z = 1.206, it
18029-445: The publication of star catalogues . Chinese astronomy was equatorial, centered on close observation of circumpolar stars , and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate observers of celestial phenomena anywhere in
18178-463: The redshift to be accurately measured as z = 0.49. Several gamma-ray bursts (GRBs) have been observed in Serpens Caput, such as GRB 970111 , one of the brightest GRBs observed. An optical transient event associated with this GRB has not been found, despite its intensity. The host galaxy initially also proved elusive, however it now appears that the host is a Seyfert I galaxy located at redshift z = 0.657. The X-ray afterglow of
18327-439: The region is VV Serpentis , a Herbig Ae star that has been found to exhibit Delta Scuti pulsations. VV Serpentis has also, like MWC 297, been found to have a dusty disk surrounding it, and is also a UX Orionis star , meaning that it shows irregular variations in its brightness. The star HR 6958 , also known as MV Serpentis, is an Alpha Canum Venaticorum variable that is faintly visible to the naked eye. The star's metal abundance
18476-431: The sky and catalogued stars, no such complete record of the stars may exist or survive. Hence, this is the oldest chart of the skies at present. According to recent studies, the map may date the manuscript to as early as the seventh century CE (Tang dynasty). Scholars believe the star map dates from 705 to 710 CE, which is the reign of Emperor Zhongzong of Tang . There are some texts (Monthly Ordinances, 月令) describing
18625-449: The sky. The two have markedly different redshifts, however, and are thus unrelated. The foreground member of the pair (4C 11.50 A) does not have enough mass to refract light from the background component (4C 11.50 B) enough to produce a lensed image, although it does have a true companion of its own. An even stranger galaxy pair is 3C 321 . Unlike the previous pair, the two galaxies making up 3C 321 are interacting with each other and are in
18774-446: The snake between the heart and the head, is a multiple star system positioned around 70 parsecs from Earth. Consisting of four stars, the system has a total apparent magnitude of 3.79 as viewed from Earth, although two of the stars, with a combined apparent magnitude of 3.80, provide nearly all the light. The primary, a white subgiant, is a Delta Scuti variable with an average apparent magnitude of 4.23. Positioned very near Delta, both in
18923-415: The source is instead a brighter, smaller galaxy a few arcseconds north. This object, designated 3C 326 N, has enough gas for star formation, but is being inhibited due to the energy from the radio galaxy nucleus. A much larger galaxy cluster is the redshift-0.0354 Abell 2063 . The cluster is thought to be interacting with the nearby galaxy group MKW 3s , based on radial velocity measurements of galaxies and
19072-498: The star's position could be deciphered by observing the dials of the equatorial ring and the right ascension double ring. A foreign missionary melted the instrument in 1715 CE. The surviving one was built in 1437 CE and was taken to what is now Germany . It was then stored in a French Embassy in 1900, during the Eight-Nation Alliance . Under the pressure of international public discontent, Germany returned
19221-409: The sun illuminates them. The former masters regarded the sun as round like a crossbow bullet, and they thought the moon had the nature of a mirror. Some of them recognized the moon as a ball too. Those parts of the moon which the sun illuminates look bright, those parts which it does not, remain dark. The ancient Greeks had known this as well, since Parmenides and Aristotle supported the theory of
19370-517: The syllabic script Linear B . Beginning in the 8th century BC, however, the Greek alphabet became standard, albeit with some variation among dialects. Early texts are written in boustrophedon style, but left-to-right became standard during the classic period. Modern editions of ancient Greek texts are usually written with accents and breathing marks , interword spacing , modern punctuation , and sometimes mixed case , but these were all introduced later. The beginning of Homer 's Iliad exemplifies
19519-441: The symbol of rebirth in ancient Greek society, and legend says Asclepius would revive dead humans using the same technique he witnessed. Although this is likely the logic for Serpens' presence with Ophiuchus, the true reason is still not fully known. Sometimes, Serpens was depicted as coiling around Ophiuchus, but the majority of atlases showed Serpens passing either behind Ophiuchus' body or between his legs. In some ancient atlases,
19668-426: The system vary erratically, and although there are two theories as to why, neither of them is completely consistent with current understanding of stars. Serpens Cauda contains a few X-ray binaries . One of these, GX 17+2 , is a low-mass X-ray binary consisting of a neutron star and, as in all low-mass X-ray binaries, a low-mass star. The system has been classified as a Sco-like Z source , meaning that its accretion
19817-441: The systematic use of decimals in the underlying parameters, and the application of cubic interpolation in the calculation of the irregularity in the planetary motions. Emperor Taizu (r. 1368–1398) of the Ming dynasty (1328–1398), in the first year of his reign (1368), conscripted Han and non-Han astrology specialists from the astronomical institutions in Beijing of the former Mongolian Yuan to Nanjing to become officials of
19966-433: The three-letter abbreviation "Ser" for the constellation in 1922. Marking the heart of the serpent is the constellation's brightest star, Alpha Serpentis . Traditionally called Unukalhai, is a red giant of spectral type K2III located approximately 23 parsecs distant with a visual magnitude of 2.630 ± 0.009, meaning it can easily be seen with the naked eye even in areas with substantial light pollution. A faint companion
20115-467: The time of the Dorian invasions —and that their first appearances as precise alphabetic writing began in the 8th century BC. The invasion would not be "Dorian" unless the invaders had some cultural relationship to the historical Dorians . The invasion is known to have displaced population to the later Attic-Ionic regions, who regarded themselves as descendants of the population displaced by or contending with
20264-481: The tip of the tail, is also a multiple system, consisting of two A-type main-sequence stars with a combined apparent magnitude of around 4.1 separated by almost half an arcminute. There is also a third G-type star with a mass and radius similar to that of the Sun. Lying near the boundary with Ophiuchus are Zeta , Nu , and Omicron Serpentis . All three are 4th-magnitude main-sequence stars, with Nu and Omicron being of spectral type A and Zeta being of spectral type F. Nu
20413-427: The two separately. However, this posed the problem of how to disentangle the two constellations, with Deporte deciding to split Serpens into two areas—the head and the tail—separated by the continuous Ophiuchus. These two areas became known as Serpens Caput and Serpens Cauda, caput being the Latin word for head and cauda the Latin word for tail. In Chinese astronomy , most of the stars of Serpens represented part of
20562-450: The very early spectral type O7.5III. The remaining star is either a blue giant or supergiant of a late O or early B spectral type. Also an eclipsing binary, the HD 166734 system consists of two O-type blue supergiants in orbit around each other. Less extreme in terms of mass and temperature is HD 161701 , a spectroscopic binary consisting of a B-type primary and an Ap secondary, although it
20711-408: The waxing and waning of the moon. The moon itself gives forth no light, but is like a ball of silver; the light is the light of the sun (reflected). When the brightness is first seen, the sun (-light passes almost) alongside, so the side only is illuminated and looks like a crescent. When the sun gradually gets further away, the light shines slanting, and the moon is full, round like a bullet. If half of
20860-625: The west and Serpens Cauda (Serpent Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the "Serpent-Bearer". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda . The brightest star in Serpens is the red giant star Alpha Serpentis , or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are
21009-588: The world before the Islamic astronomers. Some elements of Indian astronomy reached China with the expansion of Buddhism after the Eastern Han dynasty (25–220 CE), but most incorporation of Indian astronomical thought occurred during the Tang dynasty (618–907 CE), when numerous Indian astronomers took up residence in the Chinese capital Chang'an , and Chinese scholars, such as the Tantric Buddhist monk and mathematician Yi Xing , mastered
21158-461: Was Zhang Heng (78–139 CE) of the Han dynasty . Zhang was well-known for his brilliant applications of mechanical gears, as this was one of his most impressive inventions (alongside his seismograph to detect the cardinal direction of earthquakes that struck hundreds of miles away). Started by Su Song (蘇頌) and his colleagues in 1086 CE and finished in 1092 CE, his large astronomical clock tower featured an armillary sphere (渾儀),
21307-480: Was Aeolic. For example, fragments of the works of the poet Sappho from the island of Lesbos are in Aeolian. Most of the dialect sub-groups listed above had further subdivisions, generally equivalent to a city-state and its surrounding territory, or to an island. Doric notably had several intermediate divisions as well, into Island Doric (including Cretan Doric ), Southern Peloponnesus Doric (including Laconian ,
21456-452: Was a pluricentric language , divided into many dialects. The main dialect groups are Attic and Ionic , Aeolic , Arcadocypriot , and Doric , many of them with several subdivisions. Some dialects are found in standardized literary forms in literature , while others are attested only in inscriptions. There are also several historical forms. Homeric Greek is a literary form of Archaic Greek (derived primarily from Ionic and Aeolic) used in
21605-442: Was completely redesigned and refitted under the direction of Ferdinand Verbiest . Today, China continues to be active in the field of astronomy, with many observatories and its own space program . One of the main functions of astronomy was for the purpose of timekeeping. The Chinese used a lunisolar calendar , but as the cycles of the Sun and the Moon are different, leap months had to be inserted regularly. The Chinese calendar
21754-405: Was considered to be a symbol of a dynasty. As dynasties would rise and fall, astronomers and astrologers of each period would often prepare a new calendar, making observations for that purpose. Astrological divination was also an important part of astronomy. Astronomers took note of " guest stars ", usually supernovas or comets , which appear among the fixed stars . The supernova which created
21903-459: Was depicted as a hybrid of a dragon, a lion and a bird, and loosely corresponded to Hydra . Bašmu was a horned serpent (c.f. Ningishzida ) and roughly corresponds to the Ὄφις constellation of Eudoxus of Cnidus on which the Ὄφις ( Serpens ) of Ptolemy is based. Serpens is the only one of the 88 modern constellations to be split into two disconnected regions in the sky: Serpens Caput (the head) and Serpens Cauda (the tail). The constellation
22052-399: Was found in 1987 to actually be two galaxies, with the radio galaxy at the aforementioned redshift being lensed by another galaxy at redshift z = 0.845. The first example of a multiply-imaged radio galaxy discovered, the source appears to be an elliptical galaxy with a dust lane obscuring our view of the visual and ultraviolet emission from the nucleus. In even shorter wavelengths,
22201-561: Was originally from India . He was also notable for his translation of the Navagraha calendar into Chinese . The Chinese translations of the following works are mentioned in the Sui Shu, or Official History of the Sui dynasty (seventh century): Although these translations are lost, they were also mentioned in other sources. Islamic influence on Chinese astronomy was first recorded during
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