Which constellation is Polaris in?

Which constellation is Polaris in? The constellation can affect a person's character. The romance of the constellation is that it is the trace of the sun passing by. This constellation is generally mysterious and romantic, and fortune is not equal to fortune telling. I'll tell you which constellation Polaris is in.

Polaris 1 Polaris is now located in Ursa major, about 430 light years away from the earth, and it is a star with stable brightness and position that can be seen in the night sky. Because Polaris is closest to true north, people on earth have been navigating by its starlight for thousands of years.

Polaris refers to the conspicuous star closest to the north celestial pole at any time. At present, the recognized Polaris is Alpha Ursa minor (named Beichen or Gouchenyi in China), which is located at about 0.7 in the north celestial pole (in 2004). It is a late F-type high luminosity star with an apparent magnitude of 2.02, about 430 light-years away from the Earth, and its mass is about four times that of the sun. It is the Cepheid variable closest to the earth.

Because the earth revolves around its axis, and Polaris is on the north extension line of the axis, when you look at the sky at night, Polaris is motionless, and it is north overhead, so you can indicate the north. Although the tilt direction of the earth's axis will change because the earth revolves around the sun all year round, the distance between Polaris and the earth is much larger than the radius of the earth's revolution, so the change of the earth's axis caused by the earth's revolution can be ignored. So all the year round, we see that the position of Polaris in the sky seems to be motionless in the north. In fact, we just can't observe the subtle changes with the naked eye, and we feel that the earth axis always points to Polaris.

Because the earth's rotation axis will swing periodically in about 26,000 years, Polaris is not fixed and stable (it is always α Ursa minor). About 4800 years ago, Polaris was the alpha star of Draco. It was not until about 2 100 AD that the angle between Alpha Ursa minor and the North Pole was the smallest (only 27'38 "). In 4000 years, Cepheus Gamma will become the North Star. Around 14000, Alpha Lyra (Vega) became the North Star. Every 25,800 years, Polaris will cycle. For example, during Magellan's voyage, Polaris was about 8 degrees from the north celestial pole. Today, Polaris is closer to the north celestial pole with an angle difference of only 40'. According to the calculation of the earth's axis swing and stellar gravity, by 2 100, Polaris will reach the nearest position directly above the north celestial pole, only 28' away from it, and then it will gradually move away from the north celestial pole.

Ancient astronomers admired Polaris very much, thinking that it was fixed and all the stars revolved around it, which was the symbol of the emperor. Astronomers have calculated that 4800 years ago, Polaris was not today's alpha star Ursa minor, but the alpha star of Draco called right pivot in ancient China. By the year 1000, that is, the early years of the Northern Song Dynasty in China, the sky referred to by the North Pole of the Earth was 6 degrees away from the current North Star-Alpha Star in the date Ursa minor. It can be seen that it was far from Polaris. At present, the north pole of the earth's rotation axis points to the sky, and the angular distance from Alpha Ursa minor is only about 1 degree. At present, the sky pointing to the north pole of the earth's rotation axis is approaching Ursa Major at the speed of 15 arc seconds per year. By AD 2 100, the angular distance between the sky indicated by the north pole of the earth's rotation axis and the alpha star Ursa minor was the smallest, only about 28 minutes. It seems that its "position" has reached the peak of Polaris at this time. In the future, the sky pointing to the north pole of the earth's rotation axis will slowly start from Ursa minor. By about 4000 AD, Cepheus Gamma will become the North Star. By 14000, Vega, the alpha star of Lyra, will gain the reputation of Polaris. At this time, people talked about the story of the Cowherd and the Weaver Girl. Vega's position as the throne of Polaris far exceeds that of Cowherd. The time for the earth's rotation axis to swing like this is about 26,000 years. This affirms that everything is in motion, that stillness is only temporary and relative, and that the transformation of motion is eternal.

Which constellation is Polaris in? How to find Polaris?

Cassiopeia and the Big Dipper in Ursa Major are the best constellations for finding Polaris, because they are quite easy to identify. Lazy people may ask, "Can you just learn to use Cassiopeia or the Big Dipper to find the North Star?" No, according to the season and the time when the stars rise and set in the west, sometimes only Cassiopeia will be found in the sky, and sometimes only the Big Dipper will be found, so both need to be studied. Because Cassiopeia happens to be staggered with the Big Dipper in Ursa major, you can find Polaris at any time in the northern hemisphere of the earth by learning to distinguish Cassiopeia from the Big Dipper.

Searching for Polaris with the Big Dipper

Polaris is a very important indicator of field activities and ancient navigation direction, and it is also a constellation that can tell the direction from small to stargazing to large to astrophotography, and the equatorial observatory in the observation room accurately locates it.

The Big Dipper is a part of Ursa major. Graphically, the Big Dipper is located at the back and tail of Ursa Major. Of these seven stars, six are secondary stars and one is tertiary. Through the connection of the two stars in the mouth of the bucket, it extends about 5 times in the direction of the mouth of the bucket, and then meets a bright second-class star, the Polaris. This is the easiest way to find Polaris. "Star Recognition Song" has: "Star recognition begins with Beidou, and then begins from north to west." Beginners can look for other constellations in turn from the Big Dipper. Polaris is very close to the sky referred to by the North Pole of the Earth. Therefore, it always seems to be in the northern sky. It is because of its important position that it is famous. In fact, according to the brightness, it is just an ordinary second-class star, belonging to the "younger generation." It is more than 300 light years away from us. Polaris belongs to the brightest star in Ursa minor, also known as Alpha in Ursa minor. On the constellation diagram, it is on the tip of the bear's tail.

In addition, is the figure composed of the Big Dipper always stable? Is the search for Polaris always an instrument? Everything in the universe is moving and transforming, and stars are no exception. As the stars are also moving, the pattern of the Big Dipper is certainly changing. These seven stars are at different distances from us, ranging from 70 to 130 light years. Their respective running speeds and deviations are also different. Astronomers have calculated that the pattern of the Big Dipper seen 654.38 million years ago and the pattern seen 654.38 million years later are very different from today's.

Using Cassiopeia to find Polaris

In autumn and winter (September to February), Cassiopeia is most commonly used to locate the North Pole star. Cassiopeia is a constellation like the English letter "W". Note: According to different angles, the inverted "W" is "M". Facing the vast universe, the first task is to find "W". After finding the W-shaped Cassiopeia, extend the two hypotenuses of W until they intersect at a point, and then extend the intersection point to the corner in the middle of W, extending for about five times to find the Polaris.

Searching for Polaris by Vega and Altair

The Summer Triangle refers to the triangle formed by Vega in Lyra, Altair in Eagle and Tianjin in Cygnus. We can use this triangle to find the North Star corresponding to Altair based on Vega and Tianjin IV.