Andromeda is one of the 88 modern constellations in the sky, and also a Greek and Roman astronomer in the second centuryPtolemy One of the 48 constellations listed, located north of the celestial equator, the main star in the constellation AndromedaM31（Andromeda galaxy）, is one of the largest members of the galaxy group.In Greek mythology, Andromeda symbolizes the goddess who is tied to the rock to be swallowed by the sea monsterAndromeda。Andromeda is the most easily seen on autumn nights in the Northern Hemisphere, and there are also symbolsPerseusA constellation of other gods in mythology.
Andromeda is located inursa majorBelow,PegasusNearby.The head of the fairy is Picares, one of the horns of the quadrangle of Pegasus.Because of its north declination, Andromeda can only be seen in the area north of 40 degrees south latitude, and in the area south of 40 degrees will be below the horizon.Andromeda is one of the largest constellations in the celestial sphere, with an area of 722 square degrees, 1400 times the size of the full moon. The largest constellation, Serpentine, is 55% of the area, and also the smallest constellationSouthern crossMore than ten times the area.
More than 100 years ago, human understanding of the universe was limited to the Milky Way.At that time, astronomers had discovered many cloud like objects, which were collectively called nebulae.Some astronomers have observed and studiedfixed starAfter the nebula, we found that these cloud like objects are not all the same kind of objects.One of them is composed of gas and dust, which is the realGas nebula；However, another kind of cloud like objects is actually a group of stars formed by many stars together. They often have spiral structures, so they are also called "spiral nebulae".This is the Andromeda NebulaSpiral nebulaThe most typical one.
What kind of celestial system is the spiral nebula?Are they objects within the Milky Way orGalaxyOther celestial bodies?This problem is very difficult for astronomers to understand, and for a long time, no one can reach a consensus.On April 26, 1920,National Academy of SciencesA debate entitled "Cosmic Scale" was held specifically for this issue, which focused on the size of the Milky Way and the truth of spiral nebulae.These two issues are closely related.If the Milky Way is large enough and the spiral nebula is very small, then the latter is part of the former;On the contrary, the spiral nebula is independent from the Milky Way“Cosmic Island”。
In measurementCelestial distanceHighly successfulCurtisIt is believed that the spiral nebula isExtragalactic galaxy, according toAndromeda Galaxy The brightness of the novae estimates its distance, about one million light years, which is far larger than the diameter of the Milky Way.Curtis said: "As galaxies outside the Milky Way, these spiral nebulae indicate to us a larger universe than we originally thought."
yesGalaxy structureHaving given a correct explanationSaprilHe strongly disagrees with Curtis's conclusion, insisting that "the spiral nebula is a member of the Milky Way as other nebulae".His evidence is the observation result provided by Van Manen, a Dutch astronomer: the distance of the spiral nebula is only thousandsLight yearWithin the scope of the Milky Way.At that time, both sides of the debate held their own views, and no one could give enough reasons to persuade the other.The spiral nebula has become a world-famous mystery.
While many astronomers were struggling with the essence of the spiral nebula, the young astronomer Hubble passed theMount Wilson Observatory2.54m giantReflecting telescopeA number of high-resolution spiral nebula photos were taken.Hubble carefully examined these pictures of the spiral nebula. The outer edge of Andromeda M31 nebula has been decomposed into stars.From these stars he found the first Cepheid variable.The next year, he recognized many Cepheid variables from the Andromeda Nebula.Cepheid variable stars are nicknamed "astrometric ruler". The distance of these variable stars can be calculated by using the "Cepheid variable peripheral light relationship", and the location of the nebula to which they belong can be further determined.This is an openingSpiral nebulaThe right way to the mystery of nature.Hubble calculated that the distance of M31 is about 900000 light years, while the diameter of the Milky Way was known to be 100000 light years at that time.thusHubbleIt is confirmed that M31 is an independent galaxy far away from the Milky Way.At the end of 1924, Hubble's research results on spiral nebulae were recognized by everyone immediately after they were published.
Modern measurement results show that Andromeda nebula M31 is 2.2 million light years away from us, and is the farthest celestial body visible to the naked eye on Earth.M31 is about 160000 light years in diameter, almost twice the size of the Milky Way;It also contains about twice as many stars as the Milky Way;The mass is more than twice that of the Milky Way.
Andromeda Deep Space Object
M31 has seven companion star systems. M32 and M110 mentioned earlier are the brightest two of the seven companion star systems. Their apparent magnitudes are about 9 degrees. M32 has a diameter of about 7000 light-years, and M110 has a diameter of about 14000 light-years.Two companion star systems are also bright, which can be seen through telescopes with an aperture of more than 15 cm. They are NGC147 and NGC185, with diameters of 7800 light-years and 9500 light-years respectivelyElliptical galaxy, are located at about 7 ° north of M31.From the star map, these two companion star systems are both in Cassiopeia. In fact, they are physically related to M31.3 moreCompanion galaxyIts brightness is about 13 degrees or even darker, which can only be seen through large astronomical telescopes.
In fact, our Milky Way Galaxy and about 30 neighboring galaxies gather together under the action of gravity to form a relatively small group of galaxies calledLocal galaxy group。The most important member of the local galaxy group is the Andromeda Nebula, followed by our Milky Way, as well as the wheat cloudTriangular seatSpiral galaxy M33, etc.
1993Hubble Space TelescopeThe pictures of the central part of M31 obtained show that it has two cores, which is an amazing new discovery.Some people speculate that a companion galaxy may have intruded into the core of M31, but this is just a guess.
People have obtained a lot of valuable information from the observation and research of the Andromeda Nebula, and developed their understanding of the universe.The Andromeda Nebula has always been an object of concern to astronomers.
In August 2022, the joint research team of the Shanghai Astronomical Observatory of the Chinese Academy of Sciences and Shanghai Jiaotong University made important progress in the structure research of the Andromeda Galaxy (M31).The research team proposed a new idea to search for shock waves in the observational data of interstellar gas, thus providing independent evidence that M31 galaxy is a bar spiral galaxy rather than an ordinary spiral galaxy, and using fluid dynamics simulation to reproduce the main observational characteristics of shock waves in gas.[18]
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The autumn night sky is not as bright as that in spring and summer. A group of royal constellations is the biggest feature of the autumn night sky.The heroes of these royal constellations are the king, queen and princess of ancient Ethiopia, as well as the warrior who saved the princess from the monster in the sea, namely the Perseus.In Cepheus, Cassiopeia, AndromedaPerseusAmong a number of royal constellations, Andromeda has become the most eye-catching constellation because of its M31.The Andromeda Nebula is roughly located in the center of Andromeda, and can be seen in the vast area north of 48 ° south latitude[2]。
In order to successfully find the Andromeda Nebula among the numerous stars, we need to first get familiar with the autumn night sky.Autumn nightthe galaxyTurning to the northeast, you can see Cassiopeia swimming in the Milky Way. It has five very bright stars arranged in the shape of the English letter "W", which is easy to identify.The west side of Cassiopeia is Cepheus, and the east side is Perseus.Not far to the south of the Milky Way, there are four bright stars arranged in an obvious quadrangle, which is the famous autumn quadrangle.The three quadrangle stars belong to Pegasus, and only the star in the northeast corner is Andromeda.AndromedaVisual magnitudeClass 2, white.From Andromeda a to the north 12 °, and then to the east about 5 °, there is a third class double star, Andromeda gamma star, which is called "Tianda General" in Chinese.We should pay special attention to this "heavenly general". Andromeda nebula M31 is very close to it, just 1 ° away from its west.
The total magnitude of the Andromeda Nebula is 4, and the average brightness per unit area is 6. The clear and moonless night is vaguely visible to the naked eye, like a small white cloud.Its soft silvery oval shape can be seen through a small astronomical telescope.The Andromeda Nebula is a typicalSpiral galaxyHowever, since it is laterally facing us, it is not easy to see its spiral arms.Some of its structures can be seen through the astronomical telescope with a larger aperture. For example, its core is particularly bright, and the brighter the central part is, part of its spiral arms, black dust lines, globular clusters, and constellations can also be seen.In addition, we can see twoDwarf galaxyCompanion, a small, round, dense elliptical galaxyM32stayM31To the south of the core, another ellipse is slightly darker but larger and longer than M32Galaxy M110stayM31To the northwest of.There are many moreGalaxyThe relatively dim stars in the sky fill this area, adding more fascinating colors to the Andromeda Nebula.[2]
(Note:alpheratz andMirach They have almost the same apparent magnitude. Because the values provided by different sources are slightly different, these two stars are both called the brightest stars in Andromeda.But Kaleidoscope is oneRed Giant, apparent magnitude varies from 2.01 to 2.10, so it is slightly brighter on average, but not always bright.)[17]
alpheratz (Andromeda α) is an A0P type binary star with an average apparent magnitude of 2.1 and luminosity of 96L☉（L☉Refers to the luminosity of the sun), 97 light-years away from the earth.In western mythology, it represents the head of Andromeda. However, its Arabic names Alpheratz and Sirrah come from "surrat al faras", which means "the navel of a fine horse".Mienita is one of the stars that make up the "Pegasus Square" star cluster, which contains three stars:markab 、Room lodging 2andMurakami。Therefore, this star was previously thought to belong to both Andromeda and Pegasus, also known as δ Pegasus (this name is no longer officially used)[11]。
andromeda
Mirach (Andromeda β) is a red M0 giant star, located in the star cluster called "girdle", 198 light-years away from the Earth, with a magnitude of 2.06 and a luminosity of 115L☉。Its name comes from the Arabic "al Maraqq", meaning "waist" or "girdle", which is translated from Ptolemy's works.However, most Arabs believe that Mirach is part of the constellation Cetus, which is a constellation in Arab astronomy and located at the bottom of Andromeda.
General Tian No.1(Andromeda γ) is a bright orange giant star of type K3, located in the south of the constellation, with a total magnitude of 2.14.It is also a multi star system, with the yellow main star magnitude of 2.3, the blue-green companion star magnitude of 5.0, and 9.7 arc seconds of convergence with the main star.William Herschel, a British astronomer, once said: "The significant difference in the colors of these two stars implies the concept of the sun and its planets, which has made great contributions to astronomy.The companion star itself is also a binary star. Its companion star is 6.3, with a period of 61 years.The system is 358 light-years from Earth.The English name of Tianda General I Almach comes from the Arabic "Anaq al Ard", meaning "the child of the earth", which means an animal that helps lions find prey[7]。
Kususu(Andromeda δ) is an orange giant star of type K3 with a magnitude of 3.3.It is 105 light years away from the earth.
螣螣螣螣螣螣螣螣螣螣 twenty-one (κ),螣 Snake 19（λ），Che Fu Zeng 16(ο) Together with 螣螣螣螣 20 (ψ), they form a constellation called "Frederick's Honor". This name comes from the abandoned constellation Frederick Honor.螣螣螣 is a B8 type blue white main sequence star, 502 light-years away from the Earth;螣螣螣 21 (κ) is a B9 IV n type white main sequence star, 168 light-years away from the Earth;螣螣 19 (λ) is a G8 type yellow giant star, 86 light-years away from the Earth;Chefuzeng16 (o) is a B6 type blue white giant star, 679 light-years away from the Earth;螣 Snake 20 (ψ) is a B7 type blue white main sequence star, 988 light-years away from the Earth.
Andromeda is far from the Milky Way, so Andromeda rarely contains the Milky WayOpen clusterOr nebulae.Because Andromeda is far away from the bright dust in the sky, we can see many distant galaxies in Andromeda.The most famous Andromedadeep space Should belong toAndromeda galaxy, this is aspiral galaxy。M31 is one of the most distant objects visible to the naked eye. It is 2.2 million light years away from the Earth. On a dark, high vision night, it looks like a fuzzy light spot.M31 is the largest galaxy around the Milky Way and the largest galaxy in the local galaxy cluster.The diameter of M31 is about 200000 light-years, twice that of the Milky Way, and its size on the celestial sphere is about 192.4 × 62.2 arc minutes.It is a spiral galaxy very similar to the Milky Way, with an average brightness of 3.5, and is one of the brightest deep space objects in the northern sky.According to computer simulation, the Andromeda Galaxy may collide with the Milky Way in 5 billion years.
In 1923, American astronomer Edwin Hubble made groundbreaking research on M31 using the 100 inch Hooke Telescope of Mount Wilson Observatory in California[12], accidentally discovered Cepheid variable star in M31, which can be used asStandard candleDetermine the distance between other stars and us.Now this method has been widely used in the field of astronomical research.Hubble also found that the Cepheid variable star in the Andromeda galaxy is far away from us than the size of the Milky Way, which proves that the Andromeda galaxy is not a light source in the Milky Way, but exists independently of the Milky Way, and he therefore determined the existence of the galaxy (the galaxy was called "the universe island" by Hubble at that time)[13]。
The two main companion galaxies of Andromeda galaxy are M32 and M110 (NGC 221 and NGC 205 respectively), which are two very weak elliptical galaxies.The size of the visible part of M32 is much smaller than 8.7 times 6.4 arc minutes, and M110 is slightly larger[14], they appear as two more blurry spots around the light spot of Andromeda galaxy.M32 was discovered by Guillaume Le Gentil, a French astronomer, in 1749, and was later found to be closer to the Earth than the Andromeda galaxy itself.The average brightness of M32 is about 9.0. In dark places, people useBinocularsYou can see it.M110 is much darker than M32, but it looks much larger than M32, occupying 21.9 × 10.9 arc minutes in the sky[5]。
Close up of Andromeda galaxy
There are 15 Andromeda galaxiesSatellite galaxy, including M32 and M110.Nine of the 15 satellite galaxies are in the same revolution plane, which also leads people to infer that these satellite galaxies have a common origin.These satellite galaxies are usually old and gas sparseDwarf elliptical galaxy[15]。
Blue Snowball Nebula
The most famous open star cluster in Andromeda is NGC 752 (Caldwell 28), with an average brightness of 5.7.It is a star cluster loosely distributed in the Milky Way, spanning 49 minutes of arc, with about 12 bright stars.At low magnification of the telescope, we can see about 60 stars below 9.Another open star cluster in Andromeda is NGC 7686. Its brightness is similar to that of NGC 752, about 5.6. It is also a star cluster in the Milky Way.It contains about 20 stars with a total diameter of 15 arc minutes, which is more compact than NGC752[11]。
There is also a famousPlanetary nebula: NGC 7662 (Caldwell 22).It is located about 3 degrees southwest of Andromeda, 4000 light years away from the Earth.Amateur astronomers call it the "Blue Snowball Nebula" because it looks like a faint, round, blue-green spot in the telescope.This planetary nebula has an average luminosity of 9.2 degrees, a size of 20 x 130 arc seconds, and a star with a brightness of 13.2 degrees in the center[11]。
History and Myth
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In ancient Babylonian astronomy, which was older than Greek astronomy, the middle of Andromeda andPiscesA part of the stars in the Babylonian myth combine to form a constellation, symbolizing Anunitum, the fertility goddess in the Babylonian myth.[3]
Andromeda is the symbol of Andromeda, the "goddess chained" in Greek mythologyPerseusShe is the wife of the legendary Ethiopian King Kefus and the daughter of the Queen Casiopaya.In this Greek Roman myth story, Casiopaya shows off that her daughter is more beautiful than the sea fairy of Nereids, and the sea fairy turns to the sea godPoseidonHe complains and hopes that he can punish Casio Paya for his rude words, so Poseidon makes the sea monster Keto invade Ethiopia.The panicked king Kephus learned from the Amun oracle that the only way to save the kingdom was to sacrifice his daughter Andromeda to Keto.Andromeda was chained to the sea stone, and the hero Perseus used the bansheeMedusaHer head turned the sea monster into a rock and saved her.
Andromeda is the daughter of the queen Cassiopeia in Greek mythology. The head of the fairy isalpheratz , YesPegasusOne corner of a quadrilateral.Andromeda is one of the 88 constellations in the sky, located below the constellation Ursa Major and near Pegasus.Andromeda factorAndromeda Galaxy M31.M31 is about 2 million light years away from us and is the farthest celestial body visible to the naked eye. In Greek mythology,Andromeda(Andromeda) YesEthiopiaThe daughter of King Cepheus and Queen Cassiopeia, whose mother offended the sea god by constantly showing off her beautyPoseidonHis wife Amphitrite asked Poseidon to avenge her, and Poseidon sentCetusWhen Ethiopia was ravaged, Kephus was shocked and asked for an oracle. The oracle revealed that the method of salvation was to offer Andromeda.
Great Tomb Five (Perseus beta) is also known as the "Magic Star" in Europe, which symbolizes the head of Medusa[4]。Later, Perseus and Andromeda got married, gave birth to seven sons and two daughters, and established Mycenae, which was the dynasty of Perseus.After Andromeda died, Athena, the goddess of wisdom, made a constellation in the sky to commemorate her, namely Andromeda.The Perseus, Cassiopeia, Cepheus and Cepheus next to Andromeda also symbolize Perseus, Casiopia, Keto and Kephus in the myth.[5]
Ptolemy In the "Astronomical Achievements" written in the second century, there were 48 constellations listed at the earliest, and Andromeda was one of them: Rhea (Andromeda alpha) was Andromeda's head, Che Fu added 16 (Andromeda o) and 19 (Andromeda λ) as chains, and Miranda V, Miranda VI, Miranda VIII, Miranda IX and General I (Andromeda δ, πμ. β and γ) are the contours of the body and legs.Arab astronomers also recorded Ptolemy's constellation, but added several stars in Andromeda to symbolize a fish at the foot of the goddess.In 1787, German astronomerJohn BodeCombine several stars in Andromeda and most stars in Scorpio, and classify them asFrederick HonorIn memory of PrussiaFrederick the Great , but soon it was no longer in use.But different from the ancient definition, the modern Andromeda is no longer the outline of several bright stars, but a specific region of the celestial sphere containing these bright stars and surrounding celestial bodies.In 1922,International Astronomical UnionIt was decided to derive the official abbreviation of Andromeda from its Latin name Andromeda.Eugene Delpott set the formal boundary of Andromeda in 1930, that is, a polygon composed of 36 lines.According to the equatorial coordinate system, Andromeda is located between 22:57.5 and 2:39.3 of the right ascension, and between 53.19 degrees and 21.68 degrees of the declination.
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China
Kuixia in Chinese astronomy includes 9 stars in Andromeda (Andromeda β, μ, ν, etc.) and 7 stars in Pisces, which are shoe shaped.Andromeda gamma is also calledGeneral Tian No.1, belonging to General Tianda.Andromeda alpha and Pegasus gamma form a wall, the east wall of the Jade Emperor Palace and Library.The northern part of Andromeda is the Celestial Stables, and the western part, together with the Scorpion Tiger, forms a snake[6]。
arab
Arabic astronomy The "whale" (ححو, al Hut) in the constellation Andromeda includes the first, second, fourth, fifth, sixth, seventh, eighth, ninth, twenty second (Andromeda νμ、β、η、ζ、ε、δ、π. 32) and Andromeda galaxy, in addition to the outer screen V, Kuilex XIV, Kuilex XV and Kuilex XVI (ν, φ, χ and ψ of Cetus) in modern western Cetus[7]。
India
The Indian myth about Andromeda is very similar to the Greek myth: according to the ancient Sanskrit literature, the goddess Antar Madha was also tied to the rock.Because there are many similarities between the two stories, such as the close pronunciation of the goddess name "Antar Mada" and "Andromeda", scholars believe that the background of the two stories is closely related.[8]
Other regions
Andromeda is also related to the chaos goddess Diamat in Mesopotamian creation myth.Diamat gave birth to many monsters for her husband Abezu, but later decided to launch a war to eliminate these monsters.In the end, Marduk killed her, ended the war, and made Diamatt's body into a constellation for mortals to time.[9]
Marshall Islanders combine Andromeda, Cassiopeia, Triangle and Aries to form a constellation representing porpoise.The bright stars of Andromeda are mainly located in the body of the dolphin, Cassiopeia is the tail of the dolphin, and Aries is the head of the dolphin.Tuamotu islanders call Bizuer "Takurua-e-te-tuki-hanga-ruki", which means "the star of labor".[10]
meteor shower
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andromeda
Andromeda meteor showerThe history ofComet BiraHistory.Comet Bira was discovered by Montaigne in France on March 8, 1772, and its second return was made by his compatriotsPonce(J.L. Pons) found on November 10, 1805.On February 27, 1826, Wilhelm von Biela, a German, discovered the comet again.The last two timescometVegetation was observed on the 29th and 36th, but in 1826, it was observed for 72 days, so Bira got the right to name the comet.On September 24, 1832, John Herschel rediscovered the returning Comet Bira.
In 1839, people did not observe Comet Bira because of the bad position of the comet.But on November 26, 1845, Francesco de Vico, an Italian observer, was the first to observe the returning Comet Bira.There was little observational information in December, but on January 13, 1846, Matthew Fontaine Maury reported that the comet had two nuclei.Observers reported that the two comet nuclei moved away slowly, and by the end of March, the distance was 14 jiao min.Considering the distance between the comet and the earth, the distance between the two nuclei actually reaches 1.6 million miles.
The Italian observer Father A. Secchi observed the returning Comet Bira on August 26, 1852, but did not observe the second comet until September 25.The position of the comet is very bad, so people did not see it at the end of September.This is also the last time that people saw Comet Bira. In 1859, the location was not good and it was not found.1865-1866 The location was good, but the search was unsuccessful.Astronomers think the comet has completely broken up.
Comet Bira after splitting, drawn by O.W. Struve in 1852
The story of Comet Bira came to an end, and the astronomical community began to wait for newMeteor groupThe appears of.As early as December 6, 1798, Heinrich W. Brandes observed the magnificentmeteor shower。He described: "I noticed them as soon as it was dark, and it was so beautiful that I could not leave my seat." He counted the number, and the flow reached 100 per hour in four consecutive hours, then the flow quickly returned to zero.Brand observed thousands of meteors, but he failed to giveRadiant pointLocation of.On December 7, 1830, the French Abbe Railard also observed "many" meteors, but he did not give more details.The observation of the East Coast of the United States in 1838 confirmed the first two discoveries, Edward C. Herrick andBush(C.P. Bush) et al. observed the meteor shower from December 6 to December 15, and observed the meteor shower with a flow of 28-62 meteors per hour on the evening of December 7.They pointed out that "there were many fireballs... with traces on June 7".Herrick cited the observation reports in New York, Georgia and other regions, pointing out that the radiation point "is not far from Cassiopeia, and should be near the star cluster on the Perseus sword", with a total flow of 125-175 stars/hour.Eduard Heis, a German, observed the activity on December 6, 1847 and pointed out that the radiation point was located at 21 degrees of right ascension and 54 degrees of declination.
Giovanni Virginia Schiaparelli'sSwift Tuttle CometandPerseid meteor showerThis theory has aroused the interest of the astronomical community and sought more comet meteor shower correlations.In 1867,Austro Hungarian EmpireProfessor Edmond Weiss of Germany, Heinrich Louis d'Arrest of Germany and his compatriot Professor Johann Gottfried Galle in 1798 and 1838 at the beginning of independence, the orbit of the meteor cluster was the same as that of Comet Biela.Therefore, Comet Bira became one of the first comets to know about the meteor shower.Wies and Gale pointed out that there would be a Andromeda meteor shower in 1872, but De Alast thought it was December 6, 1878.
Weiss continued to compare comet La with the Andromeda meteor shower. He noticed that the ascending node of the comet gradually decreased.After careful calculation, he believed that the Andromeda meteor shower would be large-scale on November 28, 1872 or 1879.Giuseppe Zezioli observed on November 30, 1867. Seven meteors were observed at 17 degrees of right ascension and 48 degrees of right latitude, partially confirming Weiss's trend prediction.
Comet Bira will return next time in 1872, but no one has seen it.On the contrary, shortly after sunset on November 27, fragments of Comet Bira began to rush inEarth's atmosphere。The Italian observer Father P.F. Denza and others observed 33400 meteors in six and a half hours.On November 27.79, he described it as "a real fireworks show", with about 400 meteors appearing every minute.FrenchAnderson(J.F. Anderson) At 18:30 local time, there were about 30 meteors per minute, while at 19:45, there were 36 meteors per hour (November 27.78), and at 22:30, there were about 14 meteors per minute.
One of the most complete data comes fromStonehurst Observatory。After Wes' prediction,Perry(S.J. Perry) began to observe after sunset.With the help of two assistants, he accurately measured the radiation point at 26.6 degrees of right ascension and 43.8 degrees of right latitude.At 20:10 local time (November 27.84), there were too many meteors.During 20:47-21:00, a total of 13 minutes, an observer observed 512 meteors.Perry said that there should be 100 meteors per minute throughout the day.But they say 90% of meteors are dark.Perry said that a bright Andromeda meteor "is a white star with a blue tail". It is popular and has a trend of clustering. For example, 21:16 "five meteors shoot out from near Andromeda gamma at the same time".
Although Western Europe is in a good observation position, North American observers also have good results.Newton(Revised Hubert A. Newton) The observation began on November 24, and he pointed out that the radiation point is located near the Andromeda gamma star.The ZHR on the 24th was about 40-50, and it fell back to 20-25 on the 25th.It was cloudy on the 26th, but they successfully observed a rainstorm on the 27th.Newton said that a group of 2-6 observers counted 1000 meteors at 18:38-19:34 local time (about November 28.0), and fell back to 750 between 19:35-21:00.These meteors are more thanLeonid meteor showerSlow, and mostly weak.The radiation points are roughly located at 26 degrees of right ascension and 44 degrees of right latitude, and it is pointed out that the radiation points are very diffuse, with a diameter of more than 8 degrees.
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In 1873, the Andromeda meteor shower was not active at all.The activities of Dealast and Wes in 1878-1879 also did not appear.Shortly afterwards, several astronomers predicted that activities would reappear on November 27, 1885. A few weeks before the predicted time, the final hint was sent out by Crawford.
Shortly after sunset on November 27, 1885, people quickly found meteor showers in the sky.James Smieton in Scotland began to observe at 17:30, and the flow is about 25 per minute.At 18:00 (November 27.75), the traffic increased to 100 per minute, but fell back quickly.Smiton said that at 18:38, there was a peak of 70 per minute, and then the traffic dropped rapidly.The radiation point is located at 21 degrees of right ascension and 44 degrees of right latitude.He described the remnants of meteors as impressive.
William F. Denning had observed the activity a day earlier, and the flow rate was 100 pills/hour.He thinks that most meteors are too dim, so the measurement is not accurate. He thinks that the actual ZHR can reach 3600 or more.
Newton published more information about the 1885 Andromeda meteor shower in the American Journal of ScienceMarseilleThe observatory observed a high flow of 213-233 stars per minute between November 27.7-27.8, which he thought was much higher than that on November 27.76, with a ZHR of 75000.
Although Newton's work was excellent, he continued to study the orbital properties of meteor clusters. He believed that Comet Bira passed near Jupiter in 1794, 1831 and 1841-42, and produced a material cloud as thick as 200000 milesSun YellowIt moved from 256.2 degrees in 1978 to 245.8 degrees in 1885 - almost 11 days ahead of schedule.
After 1885, the Andromeda meteor shower disappeared again, but in 1892, American observers observed the eruption again, which certainly could not be compared with the ones in 1872 and 1885.However, the event on November 24, 1892 still generated hundreds of traffic per hour,CaliforniaC. D. Perrine observed 1013 meteors in 78 minutes.The Andromeda meteor shower reached its maximum on November 24, 1899 and November 21, 1904, with the ZHR of 100 and 20, respectively, which shows that the orbital material of the Andromeda meteor shower has been distributed more and more evenly.
Although the Andromeda meteor shower was almost invisible in visual observation after 1940HarvardThe Meteor Project still photographed 47 members of the Andromeda meteor shower, and calculated the linear speed of about 20 km/s.On November 14, ZHR can reach 1.In 1971,Marsden(Brian G. Marsden) and Zdenek Sekanina rechecked the orbit of Comet Chela. Lubor Kresak calculated the orbit of the meteor group at that time, and pointed out that the maximum has been advanced to November 17, with the radiation point located at 26.2 degrees of right ascension and 24.6 degrees of declination (20 degrees south of the position in the 19th century). Kresak estimated that the nearest distance from the Earth to the orbit of the comet is 0.05AU.
Andromeda galaxy
Bettie Anders Limbla(Bertil Anders Lindblad) studied the Andromeda meteor shower again in 1971 using the data of the Harvard Meteor Program and calculated the orbit.At the same time, as mentioned above, due to the influence of Jupiter, the orbit of comets has changed greatly in the past 200 years, so the orbit of the Andromeda meteor shower is constantly changing.The Andromeda meteor shower in December is older and the Andromeda meteor shower in November is newer.
After 1970, people made visual observations of the Andromeda meteor shower and achieved some interesting results.On November 22, 1970, Martin Hale observed a flow of 1 capsule per hour, and then several nights later, Mark Savill observed a ZHR of 4.From 1971 to 1975, the British Meteor Association observed the Andromeda meteor shower, with a visual flow of 3-10 meteors per hour and a radio observation of up to 35 ZHR.Members of the Western Australian Meteor Organization made observations from 1979 to 1981, with a ZHR of 3-4 and an average magnitude of 3.42, leaving traces of 3.8%[16]。
