What stars are Pisces made of?

Every year from June 5438+00 to February 12, residents in the northern hemisphere face the southern sky and look up at their heads at around 8 pm. They can see that four bright stars form a huge square-Pegasus. In the southeast of Pegasus, several small stars (ω, λ, κ, γ, θ) form an irregular shape. Several dark stars (σ, τ, π, χ, etc. ) Another irregular polygon is formed near Andromeda, which is another part of Pisces and is called "Northern Fish". The western fish and the northern fish in Pisces are arranged in a huge V-shape, which seems to be a ribbon connecting the tails of the two fish. Each side of the V symbolizes a fish, and the connection point is the alpha star at the tip of the V.

In Greek legend, the god of "love and beauty" is called "Aphrodite". When she came to Olympus, the gods were immediately attracted by her beauty. Zeus expressed his love to her many times, but Aphrodite didn't want to be with Zeus. Zeus held a grudge and married her to an ugly and lame craftsman. Later, Aphrodite broke free from Zeus, fell in love with Ares, the god of war, and married him. They have children and live a happy life. Their favorite child is eros (known as Cupid in Roman legend). Aphrodite and eros are in charge of marriage affairs on earth and in heaven respectively. Eros has two beautiful wings on her back. She often carries a golden bow and two sharp arrows-the golden arrow and the silver arrow. The golden arrow is a noble and pure arrow of love; The silver arrow represents the arrow of pure love. No matter god or man, no one can resist the power of these two sharp arrows. According to legend, one day, mother and son walked along the Euphrates River. Suddenly, a huge whale monster ran towards them. This guy has 65,438+000 snake heads, and his eyes, nostrils and mouth are all spewing flames. Aphrodite was frightened to disgrace and used his quick wits to pull little love god into the river, turned into two fish, and quickly dived into the water and escaped. Aphrodite in the water released a ribbon and tied little love god's tail to prevent it from running away. Later, in order to commemorate this event, Athena, the goddess of wisdom, raised the incarnation of the mother and son to the sky and fixed it, becoming a Pisces with eternal light.

In astronomy, Pisces is a more important constellation, because now the vernal equinox is located at the tail of "Western Fish". Vernal equinox is an important celestial coordinate point in astronomy. Astronomers tell us that the universe is boundless. Although the stars are "at different distances" from the earth, in people's eyes, the starry sky above them looks like a ball around the earth. Every star? Cave star? Snow has its place on this sphere.

Astronomers therefore made an imaginary sphere in space with the observation point on the ground as the center and the infinite length as the radius, which is called the "celestial sphere". The equatorial plane of the earth extends infinitely, and the great circle intersecting with the celestial sphere is the celestial equator. The equatorial plane and the ecliptic plane do not overlap, and there is an included angle of about 23.5 degrees between them, commonly known as "the intersection angle between the ecliptic and the equator". In addition, the celestial equator and the ecliptic have two intersections, namely the vernal equinox and the autumnal equinox. The intersection of the sun from the southern hemisphere to the northern hemisphere along the ecliptic is called the vernal equinox, and the intersection of the sun from the northern hemisphere to the southern hemisphere is called the vernal equinox. The sun passes the vernal equinox on March 2 1 day every year. On this day, the sun shines directly at the equator of the earth, and day and night around the world are almost equal in length, which is customarily called equal division of day and night. Astronomy stipulates that this day is the beginning of spring in the northern hemisphere.

More than 2000 years ago, the vernal equinox was located in Aries. Ancient astronomers believed that the vernal equinox constellation was the first constellation on the ecliptic, namely Aries. In fact, because the earth is like a swinging top, its swinging motion causes vernal equinox to slowly move westward along the ecliptic for about 50 seconds every year. So the vernal equinox is no longer in Aries, and now he is near the east of λ star in Pisces. As the vernal equinox continues to move westward, it will enter Aquarius more than 400 years later. There are many binary stars in Pisces, but they are all dark and must be observed with a small astronomical telescope. Alpha Pisces is a binary star with an orbital period of 930 years. The magnitudes of the two satellites are 4.33 and 5.23, respectively, with a difference of 1.8 arc seconds. Pisces ψ is a pair of binary stars far apart. The brightness of the two sub-stars is equal to 5, with a difference of 30 seconds. The TX star in Pisces is an irregular variable star with a magnitude ranging from 5.5 to 6. From the perspective of starry sky observation, Pisces belongs to the autumn constellation. In the autumn starry sky, readers may wish to try to find and observe this beautiful legendary zodiac sign. NGC488 is the representative of the brighter NGC galaxy in Pisces. It looks like a north-south beam with a bright core and brightness of 1 1.2. NGC524 is a bright elliptical galaxy with clear boundary and bright core, and the brightness is 1 1.5.

If you have a small telescope, search near the belt of Pisces "Northern Fish", where there is a famous celestial body that looks like a nebula. /kloc-in the 8th century, messier, a French comet hunter, first discovered it and named it M74. Because it was dark and limited by the conditions at that time, messier didn't know what celestial body it belonged to. Later, the British astronomer Earl Ross discovered through a large telescope that there was a faint halo around the bright part in the center of M74. It turns out that it is a spiral extragalactic galaxy. M74 is 30 million light-years away and consists of about 1000 billion stars. It is classified as Sc in the classification of galaxies. It looks very spectacular because it is facing us. Its spiral arms are covered with blue clusters and dark dust belts. In short, it is very similar to the Milky Way.