Backseat(Coma Berenices) YesNorthern constellationOne onBeaglesouth,VirgoTo the north of,HerdsmanAndleoIts symbol is the Queen of EgyptBerenice II (Berenice II).Backhair is also good for LeoFive Emperors OneCanisChang Chenyibetween.Among 88 constellations in the whole day, the area ranks 42nd.There are 23 stars brighter than 5.5 in Cassiopeia, and the brightest star isZhou Dingyi(Backhair β), the apparent magnitude is 4.26.After midnight on April 2 every year, the hair center passes through Shangzhongtian.The best observation month is May.
The rear engine seat is located atleoandHerdsmanBetween, north isBeagleandursa majorTo the southVirgo, no lighter than 3fixed starThe naked eye does not seem to be very eye-catching. The three brightest stars α, β and γ form a right triangle structure.Although Backhair is not impressive, it is a very important constellation in astronomy, because there is a famousGalaxy cluster。Backhair ClusterHas more than 10000 members, more than 300 million from usLight year。Because the rear engine seat is inGalaxyNorth Pole,Extragalactic galaxyIt will not be obscured by the galactic plane interstellar matter, so a large number of spectaculardeep space , including the Virgo Galaxy Cluster and the Backhair Galaxy Cluster.
thisconstellationThere are no bright stars, but these scattered stars in the dim sky look like clouds or fog, like a bunch of shiny golden hair.Backhair is right in our galaxyarcticIn the direction, when the Backhair rises to the zenith, the Milky Way will coincide with the horizon, and then we will not see the Milky Way.Just because there is little gas and dust material blocking the light in the direction far away from the plane of the Milky Way, the Herculesursa major、leoandVirgoConstellations, such asGalaxyA window into the universe beyond.For example, from here we can see that the hugeBackhair Cluster, toward the direction of Ursa MajorBig Bear Cluster, toward Virgo, the "nest of galaxies" like dense galaxies.Of course, these distant galaxies are invisible to the naked eye, and can only be observed with large telescopes.
Research History
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Ancient Greek astronomerEratostheniIt is called "Alejani's hair" or "Belleniki's hair".Ptolemy This sky area is called "hair", but it is not listed in his 48 constellations, but is divided intoleo。In ancient times, it is often associated with the hair on the tail of a lion, or divided intoVirgo。
It is generally believed that the rear engine seat is composed ofTycho Brahe It was first proposed in his catalog in 1602 and appeared in 1603Bayer designation Medium.
Rear engine seat R，Mira variable starThe brightness changes from 7.1 to 14.6, and the dimming period is 362.8 days.
Rear engine seat FK，Backhair FK variableThe reason for the light change is that the surface luminosity of the star is uneven, the rotation of the star causes the luminosity change, and because of the high-speed rotation, the star is elliptical in shape, the brightness is between 8.14 and 8.33, and the light change period is 2.4 days.
Rear engine seat FS，Semiregular variable starThe maximum brightness is 5.3, the minimum brightness is 6.1, and the dimming period is 58 days.
The star cluster is located near the gamma ray constellation, about 5 degrees in size, 2.7 million away from the earthLight year。NoMelotte111, there is no independent Messier celestial body orNGC objectsCode.The constellation Cassiopeia contains many large, diffuse open star clusters of 5-10 stars, several of which can be seen by the naked eye.
Galaxy
Virgo Galaxy Cluster
Virgo Galaxy ClusterThe northern part of the Virgo Galaxy Cluster, also known as the Backhair Virgo Cluster, lies 60 million light-years away from Earth.
M100
M100(NGC 4321): Earth facingspiral galaxy ，Apparent magnitude9.37, the observation diameter is 7Angular minute, is the largest galaxy in diameter observed in the Virgo Galaxy Cluster.41 millionLight year。Its line diameter is more than 120000 light-years, and it is one of the largest spiral galaxies in the galaxy cluster.The photo shows a bright core, two spiral arms and other fine structures.
M85（NGC 4382）：Lenticular galaxyThe apparent magnitude is 9.22, which is the brightest one in the cluster.The distance is 41 million light years, and the line diameter is 130000 light years.
M98(NGC 4192): elongatedspiral galaxy , side to the earth, the core is bright but small, and the swivel arm is large.The apparent magnitude is 10.13, the distance is 36 million light years, and the line diameter is 120000 light years.
M99(NGC 4254): Located at about 1.5 ° to the southeast of M98, the great circle spiral galaxy facing the earth has a small and bright core.
M88(NGC 4501): A spiral galaxy with multiple arms, viewed laterally at about 30 °.The apparent magnitude is 9.25, the line diameter is 110000 light years, and the distance is 41 million light years.
M91 （NGC 4548）
M91(NGC 4548): Vortex galaxy, with apparent magnitude of 10.8 and distance of 37 million light-years.
be locatedVirgoTo the north of the cluster, it is 3-4 billion light years away from Earth.It contains 1000 large galaxies and up to 30000 small ones.1957 American astronomerFritz ZweikiThe survey conducted by the director identified 29951 galaxies with apparent magnitude higher than 19.0 in the sky area.
Because this galaxy cluster is far away, the brightest galaxyNGC 4889andNGC 4874The magnitude of is only 13.Most galaxies can only be observed with the help of large telescopes.NGC 4889 is a huge ellipsoidal galaxy, located in the center of the Backward Cluster of Galaxies.
Other galaxies
M64
M64(NGC 4826), which appears to be oval, is also called "Black Eye Galaxy" or "Black Eye Nebula" because there is an obviously dim dust belt passing through the bright core.The apparent magnitude is 9.36, the line diameter is 160000 light years, and its size isMessier object afterM77No. 2, 24 million light years from Earth.Recent research has found that the direction of rotation of the interstellar dust outside the galaxy is opposite to that inside, which may be due to the collision between the galaxy and a nearby satellite galaxy 1 billion years ago.
M64 "Black Eye Nebula“
NGC4565
NGC 4565, located about 3 'southeast of Gyra retroflexa, the spiral galaxy, also known as the "Needle Galaxy" because it is side to the earth, is 16 minutes long, and is the largest galaxy in the side to the earth.The apparent magnitude is 9.56 and the distance is 20 million light years.
Globular cluster
M53
M53(NGC 5024), a globular cluster discovered by Bode in 1775, was again discovered byCharles Messier Independent discovery.Apparent magnitude 7.7 can be achieved byBinocularsSee.It is 65000 light years away from the earth, and its brightness is equivalent to 200000 suns.
NGC 5053, DistanceM53Another globular cluster 1 ° away from the cluster wasJohn Herschel Discovery.The apparent magnitude is 9.9, which is relatively diffuse, and the density of the core is small.
NGC 4147, more dim (apparent magnitude 10.2) globular clusters, and much smaller.
a quasar
PG1247+26 ° is the brightest constellationa quasar。Rear engine seat WOriginally thought to be a variable star, it was later found to belong toBL Lacertae objects 。Usually, the apparent star magnitude is 16.5, but sometimes it can reach 12.
Constellation myth
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Head of Belleniki II
HistoricBerenice II It's ancientcyrene The princess of the Egyptian pharaohPtolemy III Queen of.About 243 BC, Ptolemy III made an expedition to Syria.She prayed to God to bless her husband's safe return and cut off her hair to dedicate it to the goddessAphroditeThe Temple of God.
It is said that her hair disappeared the next day.People in the court said that they were photographed by the goddess in the sky and became the queen hair.
Dwarf galaxy
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American Astronomers Found Thousands of Dwarf Galaxies in the Backhair Cluster[1]
NASA's Spitzer Space TelescopeBackhair ClusterMore than 1000 previously unknown dwarf galaxies have been detected, which are about 320 million light-years away from the Earth.Although small compared with larger galaxies, dwarf galaxies play a key role in the evolution of the universe.Astronomers believe that they are the first galaxies to form, providing building materials for larger galaxies.They are also the largest number of surrounding galaxies: in fact, computer simulations show that large clusters of galaxies should have more dwarf galaxies than astronomers have observed.In order to find thousands of "missing" galaxies, astronomers from NASA's Goddard Space Flight Center in Greenbelt, Maryland, will come from SpitzerSpace telescopeOf 288 negatives.Each negative is exposed for about 70 to 90 seconds, and combined with the image data from Sloan Digital Sky Observation, it forms a huge mosaic pattern covering 1.3 square degrees of sky.Although it is only a small part of the sky, the team found almost 30000 new objects in a relatively short time.To the surprise of the team, most of these new objects were proved to be posterior galaxies, not galaxies outside the cluster.
Lee Jenkins, an astronomer at Goddard Space Flight Center, estimated that about 1200 dim objects are dwarf planets, which is much more than the previously confirmed number of dwarf planets.Jenkins said: "We can suddenly observe thousands of dim galaxies, which we have never seen before." The team's detailed research on the Backhair Cluster was published in the latest issue of Astrophysical Journal.How did astronomers discover these faint galaxies?The universe emits a lot of visible light, so that we can see the stars with the naked eye.But most of the light from space is invisible to the human eye, which is why the Spitzer Space Telescope, which can "see" infrared light, helps astronomers make new discoveries in the fully studied part of the universe.The team may have discovered thousands of new objects, but they said that there may be another backward dwarf galaxy hidden in the data of Spitzer Space Telescope.By using space telescopes that can see deeper into the universe, astronomers are now trying to find out how many dim objects belong to the Laguna Galaxy Cluster.
