Where is Perseus in the summer sky?

Perseus is one of the famous Polaris, and its center transits every year on165438+1October 7. People who live in the north of 3 1 degree south latitude of the earth can see the complete Perseus. Perseus is located in the east of Cassiopeia and Andromeda. Every autumn night, observers can find Cassiopeia in the northern sky, or Andromeda in the northeast of Pegasus, and then patrol along the Milky Way. Poerxiusi is easy to find. It consists of several second-and third-class stars, which are arranged in an arc or herringbone shape. Poerxiusi's Latin name is Poerxiusi, abbreviated as Per.

NGC 1275 is the main galaxy in perseus cluster. Perseus in the above picture is made up of many visible galaxies. In visible light, NGC 1275 galaxy shows a spectacular collision between two very different galaxies. This cluster of galaxies can also emit x-rays. The unusual gas fiber shown above is a very special color light emitted by hydrogen, in this case, synthetic pink. Possible fiber formation contains detailed information about the collision between two galaxies, or the interaction between the black hole in the center of the Milky Way and the gas in the surrounding inner galaxy cluster.

Poerxiusi, a hero in Greek mythology, is a symbol of Poerxiusi. He cut off the head of the terrible banshee Medusa (everyone stared at by this banshee will turn to stone). On her way home, she rescued Andromeda from the sea monster. In the starry sky, Perseus is close to Andromeda and Cassiopeia (the princess's mother). This vast starry sky tells the story of this famous Greek myth. Two globular clusters NGG869 and NGG884 represent the right hand of Perseus; Perseus Beta (Great Spirit V) represents Medusa's head and is held in Perseus' left hand. The denser part of the Milky Way passes through here, and Perseus is a fascinating constellation for those who use binoculars.

Extend the diagonal of the quadrangle in autumn, namely Alpha Pegasus and Alpha Andromeda, to twice the distance, and a bright star with apparent magnitude of 1.8m will appear, which is the brightest alpha star in Perseus.

From the star map, the most prominent symbol of Perseus is the big arc drawn by η star, which passes through γ, α, δ and ε stars until ξ and ζ stars. People call it "the Bow of Poerxiusi". China is called "Tianchuan"

The center of the string connecting η star and ζ star at both ends of the Great Arc is Perseus beta star, which was called Daling five-star in ancient China. If Perseus, a bright star, is imagined as a heroic Perseus, then Zheng, a great god, is magic eye in Medusa's hand that can turn people into stones at a glance, so it is called "magic star" in the west. Perseus β (Daling V) is a living eclipse star, which consists of two closely spaced stars orbiting each other. The period is 2 days, 2 1 hour. When the dark star winds around the front of the bright star to block the light, it will drop from 2. 1 to 3.4, which takes about 10 hour.

In fact, there is a more important reason to call it a magic star, that is, its brightness will change, flickering, like a mysterious magic eye. The brightness of Lingwu changes regularly. Every two days for 20 hours and 49 minutes, its brightness changes from 2.3m to 3.5m and then to 2.3m, with a period. The ancient Arabs called Dalingwu "the devil in the forest", so it seems that they also noticed its blackening at that time.

Extend the distance between η star and η star at the top of Perseus arc by twice. If you look carefully, there is a faint light here. In fact, these are two open clusters. Because they are close together, just like binary stars, they form the double star cluster.

M34 open cluster, about 1400 light years away from the earth, can be seen with binoculars or small telescopes, and its size is about a full moon. The brightest star in a cluster is a magnitude 7 star. NGC869 and NGC884 (Perseus η and χ double galaxy clusters) are two open clusters in Perseus. They are visible to the naked eye and can be clearly seen with binoculars or small telescopes. They are all as big as a full moon.

Perseid meteor shower

Perseid meteor shower is one of the seven famous meteor showers. It appears from July 17 to August 24th every year. It is not only numerous, but also almost never absent from the summer sky. It is the most suitable meteor shower for non-professional meteor shower observers, ranking first among the three periodic meteor showers throughout the year. Comet Swift-Tuttle is the mother of Perseid meteor shower. 1992 around the perihelion of the comet, the Perseid meteor shower shone brilliantly, and the number of meteors reached more than 400 per hour.