Why are Gemini twins in the night sky?

In winter, although there is no obvious galactic landscape in summer, scorpions with claws and people shooting stars with bows, bright Orion, shining Sirius and galloping Taurus also make the starry sky in winter night lively. There is a pair of good brothers who patrol the night sky hand in hand in the cold winter. They are twins in the night sky-"Gemini".

Gemini is easy to find in the night sky. The simplest and most intuitive way is to find the symbol of the winter constellation-Orion, and then connect Betelgeuse (the upper left corner of Samsung belt) with Betelgeuse (the lower right corner of Samsung belt) to extend the distance by about twice, so that you can find two bright stars with a short line of sight. They are only about 4.5 apart, and they are Gemini's Alpha Star (Beihe II) and Beta Star (Beihe III).

In ancient western mythology, Castel, the elder brother of Gemini, was the son of Sparta, and Procus, the younger brother, was the son of Zeus, so he was immortal. The two grew up together and had a very good relationship. After my brother Caster died, only paulus was immortal. So Procus asked Zeus to go to the grave with Castor. Zeus then agreed that the two brothers would take turns living in heaven and hell. To commemorate the twin brothers, ancient Rome also built temples for the twin brothers-the temples of Caster and Polonius.

Gemini is one of the zodiac signs, with an area of 5 13.76 square degrees, accounting for 1.245% of the whole day, ranking 30th among the 88 signs in the whole day. Gemini has 47 stars brighter than 5.5, the brightest star is Beihe III, and the apparent magnitude is 1. 14. This constellation is just above the observer's head when the Gemini center passes through the upper meridian on the night of 65438+10.5 every year.

Although Gemini beta star (Beihe III) is named "beta" star, it is brighter than "alpha" star (Beihe II) from the earth. It is 33.7 light years away from the earth and its luminosity is 32 times that of the sun. It is one of the recent red giant stars and one of the brightest stars in the universe. Observed with binoculars, the orange of Beihe III is in sharp contrast with the blue of Beihe II, which is very bright. This spectacular sight can be clearly seen in most parts of our country.

Although Beihe II and Beihe III are described as "twins" of constellations, their characteristics are quite different. The former is a blue and white main sequence star, and the latter has entered the stage of red giant star. Moreover, Beihe II and Beihe III are still moving in two opposite directions.

Speaking of Gemini, I have to mention another famous astronomical phenomenon related to it-Gemini meteor shower. As one of the three most stable meteor showers in the northern hemisphere (the other two are the quadrant meteor shower of 65438+June 4th and the Perseid meteor shower of August 3rd), it comes to the earth every year on the night of 65438+February 13, and makes those days a carnival night for astrophotography fans. Gemini meteor shower is a large-scale explosion of meteors in a short time with the sky near Gemini as the radiation point. At the highest, the zenith flow per hour can reach about 120.

The mother of Gemini meteor shower is asteroid 3200 Phaeton, which makes it one of the few meteor showers whose mother is not a comet. Most meteors in the group are bright medium-speed meteors, and there are many colors such as red, yellow, blue and green besides white meteors. Last June+February, 5438, under the organization of domestic fans, the author went to Tongliao, Inner Mongolia in four teams to observe and photograph the meteor shower, and felt and recorded the splendor of the stars falling like rain in the cold.