The constellations areastronomyAppears inearthAn informal constellation in the skyfixed starGroup.imageconstellationSimilarly, they are basically composed of some stars in the same direction, but there is no physical substantial correlation, and they often have significant differences in the distance from the Earth.A star cluster can be composed of stars in the same constellation or stars from different constellations.They are mainly composed of simple shapes or a few stars, which makes their patterns easy to identifynight skyIt is especially useful for beginners.
Background
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Fig. 1 Cluster
Even in the twilight of civil use, it is easy to connect various stars in the form of point to point combination or stick.Basically, constellations are randomly grouped, and different cultures will create different constellations, but some obvious shapes tend to be similar, such asOrionandscorpio。Historically, there was no official document showing the clear distinction between constellations and constellations.Anyone can arrange and name combinations of stars, which may or may not be generally recognized.So far, our own constellations can still be traced back to those of Sumerians.As shown in Figure 1
Fig. 2 Star Cluster
The current list is based onancient Greek-RomeOfastronomer：AlexandreOfClaudius Ptolemy(c 85 – c 165), the 48 constellations he listed were not only accepted, but also used as standards for 1800 years.When constellations are considered to be composed of only stars, they can always be handed down. Stars not in the figure can play the leading role in new groups or be re squeezed to create constellations.There are two astronomersJohann Bayer (1572-1625) andNicolas Louis de Lacaille (1713-1762) tried to expand Ptolemy's catalogue.Bayer added 12 constellations as suggested by Ptolemy, and Lakay did not observe the sky in ancient timesantarcticSome new constellations have been created nearby.Many constellations proposed by them have been accepted, many of the remaining constellations are outdated, and it is necessary to clarify which constellations are stars.The location rules were finally determined in 1930. The International Astronomical Union (IAU) divided the whole sky into 88 constellations and gave clear boundaries. Other groups are star clusters.As shown in Figure 2
Key points to remember -
The seasons are marked in the Northern Hemisphere.staysouthern hemisphereThe seasons are opposite.The smaller the number of levels, the brighter the stars.So a star of order 1 is brighter than a star of order 2.The brightest stars are first class stars, but a few brighter stars, after all, are limited in number, and may also be negative.
The real star cluster is a star with gravity correlation, not a cluster.
Seasonal constellation
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Due to accidental coincidence, there are huge star clusters in the four seasons near the top of the head at midnight.They are composed of bright stars and present simplegeometryShape.
Figure 3 Star Group
The sign of spring is for the femaleDiamonds, byArcturus(Shepherd alpha)Cornucopia(Virgo alpha)Five Emperors One(Leo beta) andChang ChenyiIt is composed of four stars.Connect the Big Horn and the Five Emperors in an east-west line segment to form an equilateral triangle with Chang Chen Yi in the northSpring TriangleThe other triangle is formed with the southern corner of Antares;Combine these two triangles to form the shape of a diamond.The diamond was once stretched at 38 ° north latitude and 11 ° south latitude, which was too large to be seen at a glance.Formally, the diamond of this star spans the four constellations of Hercules, Virgo, Leo and Hound.As shown in Figure 3
The Summer Triangle isTianjin IV(Cygnus alpha)a cowboy(Alpha Aquila) and Vega（Lyra alpha）These three stars are all very easy to identify first class stars.This triangle marks the equatorial zone of the Milky Way where the Milky Way is located.
Figure 4 Star Group
The autumn quadrangle is a huge square composed of Pegasus, which is composed of four stars, namely, Sumi (α Pegasus), Sumi (β Pegasus), Mii (γ Pegasus) and Mii (α Andromeda), representing the body of Pegasus.In the autumn night, you can catch a glimpse of the complete constellation.As shown in Figure 4
stayWinter nightsYou can see the winter big ellipse composed of two thirds of the first class stars (6 of 21) in the whole sky. They are Sirius (alpha Canis Major), Nanhesan (alpha Canis Minor), Beihesan (beta Gemini), Capella (alpha Auriga), Aldebaran (alpha Taurus), Rigel (beta Orion) and Betelgeuse off center（Orion alpha）。Because it is somewhat flat, it is more appropriate to call it an ellipse than a circle.Some people like to call it the winter hexagon.The triangle formed by Sirius in Canis Major, Nanhe in Canis Minor and Betelgeuse in Orion is calledWinter Triangle。The equilateral triangle formed by these three stars is located at the equator of the celestial sphere, so it can be seen all over the world.
Examples
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Undoubtedly, the most famous star cluster is the Big Dipper or Plough.It is composed of seven bright stars in the constellation Ursa Major, representing the hind legs and exaggerated tail of the bear.Big DipperThey are often beginnersNorthern HemisphereThe first star cluster in the sky.Little Beargrow a tailBesides, other parts almost never appear, but its pseudonym: Little Big Dipper is widely known.
Alias of constellation
Fig. 5 Constellation
Ursa Minor is not the only constellation that is not easy to see the shape of the objects it represents. Very few of them have earned nicknames for some constellations.These nicknames are another type of star clusters. It is usually easy to explain the origin of these star clusters by examining the constellation names in the bar chart displayed on these star constellations.As shown in Figure 5
The most famous isCygnusNorth Cross of.From the swan tail at the topTianjinFour (Cygnus alpha) starts to reach the beakThe chariot road increases by seven(Cygnus β), transversely from one wing Tianjin IX (Cygnus ε) to the other wing Tianjin II (Cygnus δ).
The giant hook isPolynesiaPeople give Scorpio the traditional name.This pattern is very obvious. If the connection from Antares II (α Scorpio) to Apartment IV (β Scorpio) and Apartment I (π Scorpio) replace the connection from Apartment IV to Apartment IV through Apartment III (δ Scorpio), a huge capital J can be formed.
A complete butterfly figure can be formed by adding a vertical line on the left and right sides of the main modeling map of the constellation of Wu Xian.
Although this is not an ancient concept, the Shepherd can be regarded as aice creamBut he is more famous for the shape of kites.
The stars in Cassiopeia form the letter W, which gives him the nickname of W constellation.
In Australia, the constellation Hymenopterus is called the frying pan to help find stars in the south.
Local constellation
A constellation may only be a part of the complete constellation pattern traditionally mentioned, such as: * Orion belt;stayAquariusWater tank;
The stick of Hercules.
There are many others too numerous to enumerate.
Nonlocal constellation
Fig. 6 Star Cluster
The stars of other constellations are also composed of a single constellation, but they are not traditionalmodellingFig.As shown in Figure 6
The four stars in the center of Hercules: Tianji III (Hercules ε), Tianji II (Hercules ζ), Tianji Zengyi (Hercules η) and Maiden Bed I (Hercules π) constitute the famous dome stone.
In the head of Leo, fromXuanyuanSeven (Leo ε) ends atXuanyuan XIVThe curve formed by the star (alpha leonide), much like the question mark in the mirror image, has long been known as the sickle.
Archer's bow and arrow are also famous teapots (even there is a little hazy gas like water vapor near the mouth of the teapot).
The Dog Kingdom is a quadrangle composed of four dim stars, Dog Kingdom I, Dog Kingdom IV, Dog Kingdom II and Dog Kingdom III (ω, 59, 60, 62) in the front leg of Sagittarius.
In addition, the four stars at the bottom of the boat, Nanchuan 5, Haishi 5, Nanchuan 3 and Nanchuan 4 (β, ν, θ, ω), form a perfectly shaped diamond (diamond cross).
The small pan can be:
The belt and dagger of Orion end with Fasan (Orion I) as the handle, and the outer edge is as far as Shensuzengsan (Orion η).
stayAustralia, is part of the constellation Peacock.
Tianshu and Tianxuan (α and β in Ursa Major), these two stars are the end of the spoon, and they are usually called the polar stars: Polaris (α in Ursa Minor) can be found by connecting Tianxuan to the direction of Tianshu and extending five times.
South Gate II (Alpha Centauri) and Hippocampus I (Beta Centauri) are the polar stars of the South Pole, which can point out the position of the Southern Cross and help distinguish the Southern Cross and the false cross.
Cross border groups
Like seasonal constellations, there are also some other constellations composed of stars in more than one constellation.
Another star cluster, like the diamond of a female, is also composed of a pair of equilateral triangles.Sirius (Canis Major alpha), Nanhe III (Canis Minor alpha) and Betelgeuse IV (Orion alpha) form the northern triangle (Winter Triangle), and then SiriusSagittal increased by 22(Zeta in the stern) and one in law (α in the constellation Dove) form the south triangle.Although it is not like a diamond, the two triangles are staggered, not edge to edge but vertex to vertex, and the shape is likeAncient EgyptX of.The name comes from its shape, and it crosses the celestial equator, which is easier to see in the southern part of the earth than in Europe.
The diamond pattern is composed of four stars: three stars in the head of the constellation Draco, namely, the four stars (Draco gamma), the one star (Draco ξ) and the three stars (Draco beta), plus the five stars in the foot of the constellation Hercules.
The false cross is composed of Tianshe III (Sail Seat δ), Tianshe V (Sail Seat κ), Haishi I (Bottom Seat ε) and Haishi II (Sail Seat ν).Although these stars are not as bright as the Southern Cross, they are larger and better shaped than the Southern Cross, so the navigators of some ships often make mistakes.
Form of telescope
In addition to the large range of star clusters, there are also small and obviously suitabletelescopeThe star cluster of.
Although the image in the photo is upside down, the Bloch star cluster in the constellation Fox is still easily recognizable.
Gambo beaded in Deer and Leopardnight skyA colorful toothpick.
Ancient constellation
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South seatThis is a special case.In the early days, he was the largest constellation created by Ptolemy. When Lakay rebuilt the constellation of the southern sky, he divided it into several parts of a ship in his Coelum Australe Stelliferum (1763): the bottom, stern and sail.In 1930,International Astronomical UnionIt is also believed that the southern constellation is really too big, so these old constellations are officially recognized as three constellations: Carina, Vela and Puccida, while the original southern constellation is regarded as a constellation.
SoutherlycrossIt is not a constellation, but a genuine constellation:Southern crossHowever, Uranometria (1603) in Bayer is still a constellation in the back leg of Sagittarius, which was separated from Sagittarius as a constellation in 1930.
The constellation Sagittarius has been reduced once before. At first, the constellation Jackal was only a part of this constellation. It was regarded as a strange beast possessed by the Sagittarius, and it was used around 200 BCIbaThe valley has been separated from the Ptolemy list and has existed independently.
In the original pattern, there are some dim stars in the tail of Leo, which form a spray after the straight body, vividly describing the tail.Perhaps before Ptolemy, Conon of Alexandria called this constellation "Berenico's hair" in 243 BC in memory of his queen. Then Tycho accepted this statement and became a constellation. Bayer recorded this result and redrew the lion's figure. The International Astronomical Union also recognized the constellation as a constellation.
Even Libra, which is highly respected, was once a constellation. Until the middle ages around 500 BC, there were only 11 constellations on the zodiac.Referring to the Bible (Genesis 37:9), it is also clear that "there are 11 constellations or constellations in the zodiac".At that time, the claws of Scorpio were extended to Dizuzengqi (α 1 Libra), the claws of the south, and Dizusi (β Libra), the claws of the north.Later, when Virgo was redefined as Astraea, the goddess of justice, the claw became the Libra in her hands before the Ptolemaic era.Libra has become an independent constellation unrelated to its neighbor (Scorpio), but the name of the star still reflects that it was once a "claw" star cluster, and in the old pattern, it is a star cluster in Virgo.
The constellations mentioned here are those that have been integrated into constellations and have not been accepted as constellations, or past constellations outside the constellations and those that are now considered outdated. Please refer to the former constellations.
Non constellation
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There is a similar feeling here. The objects that do not fall within this definition include the Milky Way, nebulae andOpen cluster。
The Milky Way appears innight sky, a hazy white light belt across the entire celestial sphere divides the night sky into roughly equal two hemispheres.Many cultures are concerned that the Milky Way is "wide in heavenWhite Avenue”Ofmyth, earlyGalileo telescopeIt has been found that the shining light of the Milky Way is caused by countless dim stars and other substances.Similarly, the Magellanic Cloud is not a star cluster, but a galaxy.
Nebula is a cloud of gas and dust in the galaxy. Whether it is as luminous as a pelican or as dark as a horse's head, it is clear that it is not a cluster, because there is no star in their composition.
Open star clusters are groups of stars. They are bound by each other's gravity and gather together, and move in the same direction at the same speed in the galaxy.Because these formations are not man-made, but real phenomena, they are not regarded as star clusters, among which the most famous ones are the Pleiades star cluster in Taurus (M 45), the Hyades star cluster, and the Honeycomb star cluster in Cancer (M 44).(But part of the Hyades cluster, together with Aldebaran in the same direction of the line of sight, forms the "V" shaped part of Taurus, which is regarded as a star cluster.)
Two examples may be the best examples of how to form the detailed rules of a constellation: embedded and illuminatedOrion Nebula(M42).With telescopes, it can be broken down into four stars forming a ladder shape, which is called a trapezoid. Even if more stars are found, this cluster still retains the name.However, after that, it was determined that the Orion Nebula was a star nursery, and the trapezoid was actually an open star cluster, so it was no longer considered a star cluster.On the other hand, M73 in Aquarius used to be regarded as an open star cluster, which was composed of unrelated stars, so it is now regarded as a star cluster.
