Cassiopeia is a recognizable constellation with fiveBrightest starForm a very unique W or M shape (depending on the viewing season).Because it is associated withPolarisThe distance is not farHigh latitudeThe constellation of the region will not fall all night, andBig DipperRelative, yesPolar arch constellationIt also refers to one of the polar constellations.[2]
Cassiopeia is aThe Big DipperAmong the comparable constellations, there are at least 100 stars that can be seen with the naked eye, but only six or seven are particularly bright.There are three second-class stars and two third class stars to form an obvious Englishcapital"W" shape with opening facingPolarisThis is the most important symbol to identify Cassiopeia.Cassiopeia can also look for:Big DipperOf“Tianshu"AndPolarisThe connecting line of the Milky Way can reach Cassiopeia, the "shore" of the Milky Way, by extending about the same length to the south.
Cassiopeia is a recognizable constellation with fiveBrightest starForm a very unique W shape.Because it is associated withNorth Celestial PoleThe distance is not farHigh latitudeThe constellation of the region will not set all night, and is opposite to the Big DipperPolar arch constellationIt also refers to one of the polar constellations.[3]
Constellation of Cassiopeia
Extend northwardAutumn quadrilateralOfPegasusGamma stars andAlpha Andromeda, there is a bright second-class star, which isBeta Cassiopeia(along hereLineFurther north, you can see Polaris).The five brightest stars, β, α, γ, δ and ε, in Cassiopeia form aEnglish letterThe shape of "M" or "W" is the most obvious symbol of Cassiopeia.The most interesting one is Cassiopeia gamma (Chinese: Ce), which is aBlue giantThe brightness changes with the expansion of the stellar gas layer.Cassiopeia also has several famous star clusters, such asM52andNGC 457TwoOpen cluster。
Cassiopeia's "W" andBig DipperOpposite Polaris, so when Cassiopeia rises tozenithAt that time, the Big Dipper was at the lowest point in the sky. At that time, it could not even be seen in the south of China.Without Beidou, we can connect the midpoint of δ star, ε and γ star, and extend northward to findPolarisHas.
Wang Liangsi(Cassiopeia alpha) is aKonductra。The master star is an orange giant,Apparent magnitude2.2, 229 light years away from the earth.The companion star is far away from the main star, with an apparent magnitude of 8.9.
Wang Liangyi(Cassiopeia β), also known as Caph, which means "hand", is a white star with an apparent magnitude of 2.3 and a distance of 54 light-years from the Earth.The 16th century Arab astronomer Al Tizini named this starAl Sanam al Nakah, meaning "the hump of a camel".
Policy(Cassiopeia gamma) is aShell star, a very fast rotatingVariable star。This causes stars to periodically eject rings of matter.The apparent magnitude of Ce is 3.0 at its darkest and 1.6 at its brightest.
Penthouse Path III(Andromeda δ), also known as Ruchbah, which means "knee", is aFive TombsTypeEclipsing binary。The apparent magnitude is about 2.7, the variation range is 0.1, and the period is 2 years and 1 month.Attic three is a blue and white star, 99 light-years away from Earth.
Penthouse Path II(Epsilon Cassiopeia) is a blue white star with an apparent magnitude of 3.3, 442 light-years from the Earth.[7]
Cassiopeia A（Cas A）It's in CassiopeiaSupernova remnant(SNR, supernova remnant) and the brightestsolar systemOutsideRadio wave source, its frequency in the sky is higher than 1GHz.This oneSupernovastayGalaxyInside, about 11000 light-years (3.4Kilosecond gap）。The cloud gas from the expansion of the material left by the supernova is about 10Light year（3Second gap).stayAmateur astronomyWith a 234 mm (9.25 inch) aperture telescope coupled with an appropriate filter, it can already be observed at the wavelength of visible light.
It is estimated that the light generated by the explosion of this star first arrived at Earth about 300 years ago, but there is no information about supernovaeHistoryIt records the existence of this wreckage.Because of theNorthern HemisphereinHigh latitudeCassiopeia is visible all the year roundPolar arch constellation, so this may be due toInterstellar dustAbsorption ofvisible lightAbsorbed before reaching Earth.However,John Flamsteed In productionCatalogueIt was recorded on August 6, 1680Cassiopeia 3(English: 3 Cassiopeiae) It's a 6 gradeDark star。This view tends to explainProtostarIs abnormalHigh qualityAnd a lot of outer material was thrown out before the explosion.These outer layers will mask the protostar fromStellar interiorVisible light released during collapse.
On November 11, 1572, in the Ming Dynasty, a new star suddenly appeared in Cassiopeia, which can be seen in the daytime.This star appears three timesWeeks laterIt began to darken slowly, and it didn't disappear from people's view until March 1574, 17 months later (this sudden appearance of "bright stars" is called "bright stars" in astronomy“Supernova explosion”）。But 380 years later, radio wave radiation was found at this location. It is a powerful radio source, called Cassiopeia B radio source. It isSupernovaThe remnants of the explosion.[4]
Constellation myth
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MYTHOSIn China, Andromeda is the daughter of King Kefus and Queen Cassiopeia of Ethiopia. Cassiopeia offended the sea god by showing off her daughter Andromeda's beautyPoseidon His wife, Amphitri, wanted Poseidon to avenge her, so Poseidon sent the whale sea monster to ravage Ethiopia.King Kephus was shocked and asked for an oracle. The oracle revealed that the way of salvation was to present Princess Andromeda.
Andromeda's parents chained her to the rock represented by the constellation Cetus. LaterPerseusSeeing such a tragedy, he took out the head of Medusa, the snake haired witch, petrified the sea monster and rescued the princess.And Cassiopeia was punished foreverarctic circleTurn.[1]
