Is Polaris in the north? Can you see it with the naked eye?

English name: Polaris, Polaris, Polaris

Item code: HIP 1 1767

Alpha Ursa minor is now also called Polaris, MSI or MSI.

Polaris is a bright star in the northern part of the sky. It is very close to and almost opposite to the north celestial pole.

Polaris

Seen from the northern hemisphere, the position of the earth's axis is almost unchanged, which can be used to identify the direction. However, due to precession, Polaris is not a star whose position will never change, and it will be Vega by the year 14000. 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.

Polaris belongs to teenagers. It is about 323 light years away (that is, the light from the Polaris we see). Polaris is the brightest star in Ursa minor, also known as Alpha Star in Ursa minor. It is an F-type high luminosity star with a late spectrum, with a distance of about 323 light years and a mass about five times that of the sun. It is the brightest star closest to the earth and is at the tip of the bear's tail in the constellation diagram.

symbolic meaning

It is precisely because the position of the North Star is relatively stable and unchanged that it gives people a sense of loyalty and has its own position.

From the perspective of life, Polaris has the significance of leading us to our goals, just as it can tell us the direction.

From the perspective of love, Polaris symbolizes firmness, persistence and eternal protection.

If it is anthropomorphic, then it must have a commitment to the stars near it, otherwise it will not insist on guarding, such as the moon. Although far away, Polaris is still guarding. So Polaris is firm, symbolizing that it will never change!

Polaris once said to the earth, "If you get lost, look up at me, and I will wait for you here forever." So people who get lost will look up at the North Star.

2 position

Connect a straight line between Tian Xuan and Shu Tian at the front of the Big Dipper, extend the distance by five times, and you will meet a bright second-class star, which is the North Star. This is the easiest way to find Polaris.

Beginners can look for other constellations in turn from the Big Dipper. Because the earth's axis of rotation will swing periodically in about 26,000 years, Polaris is not fixed (always α Ursa minor). About 4800 years ago, Polaris was the alpha star of Draco. Until the year 2000, the angle between Alpha Ursa minor and the North Pole will become the smallest (only 28'38 "). In 4000 years, Cepheus Gamma will become the North Star. Around 14000 BC, Alpha Lyra (Vega) became the North Star.

Polaris

Polaris (Gouchenyi) is also a three-in-one system. The distant companion star (Polaris B) can be clearly observed with a small telescope. The nearby companion star (Polaris) is too close to Polaris (the apparent distance is only 0.2 ",but the actual distance is 18.5), so it is too dark to see. It was not until early August 2005 that the Hubble telescope captured its image.

Polaris is very close to the north pole of the earth in the sky. 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.

replace

Different from the western astronomical system centered on ecliptic coordinates, China developed an astronomical system centered on equatorial coordinates in ancient times. In this system, Polaris is located just north of the celestial sphere, which undoubtedly has a unique position. In ancient China, it was often used as a symbol of the emperor. However, due to the periodic slow swing of the earth's rotation axis, Alpha in Ursa minor has not been the North Star since ancient times. Therefore, the position of the sky indicated by the north pole of the earth's rotation axis is also changing, and the "throne" of Polaris may also take turns to sit in the village. The sky pointed to by the north pole of the earth's rotation axis moves at the speed of 1.5 arc seconds per year. 4800 years ago, Polaris was not the alpha star of Ursa minor, but the alpha star of Draco, which was called the 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 still 6 degrees away from the constellation Ursa Major. It can be seen that it was far from Polaris. 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. 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. In the future, the sky pointing to the north pole of the earth's rotation axis will gradually move away 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. The time for the earth's rotation axis to swing like this is about 26,000 years. This shows that everything is in motion, stillness is only temporary and relative, and the change of motion is eternal. And around 28000 AD, the North Celestial Pole will point to Alpha Ursa minor.

function

Polaris is a very important indicator of field activities and ancient navigation direction. From stargazing to astrophotography, the accurate positioning of the Equatorial Observatory in the observation room is also a very important constellation to identify the direction.

Polaris is located in Ursa minor, about 323 light years away from the earth. 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.

3 kinds of brightness seats

47. Polaris (Ursa minor)

1.？ Sirius 2. Canopus 3. South Gate (Centauri) 4. Arcturus (Capricorn)

5.？ Vega (Lyra) 6 Capella (Auriga) 7. Betelgeuse (Orion) 8. South Husang (small canines)

9 .？ Water Committee I (Bojiang) 10. Betelgeuse (Orion) 1 1. Horse belly one (Centauri) 12. Altair (eagle)

13.？ Bi Su Wu (Taurus) 14. Cross 2 (South Cross) 15. Antares (Scorpio) 16. Kakuiyi (Virgo)

17.？ Beihe III (Gemini) 18. Beiluoshimen (South Pisces) 19. Cross three (Southern Pisces) 20. Tianjin No.4 (Cygnus)

2 1.？ Xuanyuan XIV (Leo, the first-class star in the above picture)

22.？ Sagittarius VII (Canis Canis) 23. Beichuan II (Gemini) 24. Cross I (South Cross) 25. Rongzhong (Scorpio)

26.？ Betelgeuse (Orion) 27 Capella (Taurus) 28 Carina) 29. Betelgeuse (Orion)

30.？ He Yi (crane constellation) 3 1. Yuheng (Ursa Major) 32. Shu Tian (Ursa Major) 33. Tianchuan No.3 (Poerxiusi)

34.？ Tiansheyi (Vela) 35. Giussan (Sagittarius) 36. Sagittarius I (Canis Canis) 37. Haishiyi (karina)

38. Shaking Light (Ursa Major) 39. Endura V (Scorpio) 40. Callinan (Auriga)

4 1.？ Triangle III (south triangle) 42. Su Jing III (Gemini) 43. Peacock Eleven (Peacock) 44. Military City No.1 (Canis Canis)

45.？ Constellation I (Ophiuchus) 46. Lou Su III (Aries) 47. Polaris (Ursa minor) 48. Cepheus IV (Sagittarius) 49. Toast hole (Pisces) 50. Betelgeuse (Orion)

4 don't move secrets.

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.

companion star

As early as more than 200 years ago, astronomer Herschel discovered that Polaris has a bright companion star-"Polaris B", and its average linear distance from Polaris is 2400 astronomical units (one astronomical unit is the distance from the earth to the sun, which is about 65.438+0.5 billion kilometers). More than half a century ago, astronomers speculated that Polaris had another very close companion star, which together with Polaris B formed a Trinary star system. But this companion star has never been observed because it is too close to Polaris and the light is too dim.

Nancy Evans of Harvard-Smithsonian Center for Astrophysics and others first observed this mysterious companion star-"Polaris B" in August 2008 with the help of the advanced mapping camera on the Hubble telescope. They found that the average linear distance between this companion star and Polaris is 18 astronomical unit. Observing the distance between Polaris and Polaris B on the earth is like distinguishing a coin from 30 kilometers away. Only the advanced mapping camera of Hubble Space Telescope can do it.

Astronomers also found that Polaris is a Supergiant star with active internal energy response, and its brightness is more than 200 times that of the sun, while Polaris B is a dying dwarf. Therefore, its light is always blocked by Polaris and becomes an "invisible companion", and this time its stealth state was seen through by Hubble.

5 star finding method

You can find the Big Dipper first, and then find the North through the Big Dipper.

Polaris

Polaris. 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 finds the 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.

Will the pattern of the Big Dipper never change? Will it always be a "tool" to find the North Star? Of course not. Everything in the universe is moving and changing, 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. At 100 light-years, their respective speeds and directions are 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.

Polaris and China Traditional Culture

Traditionally in China, Polaris is of extraordinary significance, such as Taiyi in the Five Emperors era in 2263 BC and Di in the Duke of Zhou in 1097 BC. This is because they seem to be fixed in the sky and supported by the stars, so they are regarded as the owners of the stars.

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