Just ask for the details of Polaris.

Polaris refers to the star closest to the north celestial pole. The current Polaris is Alpha Ursa minor (Dog Chen Yi). Gouchenyi is a three-in-one system. The main star Gouchen I A is a yellow Cepheid variable star surrounded by a bright yellow dwarf Gouchen I B at a distance of 2400AU. Gou Chen -B was seen by William Herschel as early as 1780 and can be observed with modern small telescopes. 1929, it was discovered that Gouchen -A is a split binary star with a very close dwarf companion, called Pα Ursa Major, aα Ursa Minor, or Abα Ursa Minor. In June, 2006, 5438+ 10, we can see these three stars in the Hooke-Chen Trinity at the same time from the released photos of the Hubble Space Telescope. The nearest dwarf is only 18.5AU away from Gouchen -A, which is about the distance from the sun to Uranus, which is enough to explain why it is hidden in the light of Gouchen-A.. Gouchen Chen-yi is a Cepheid variable star belonging to the first constellation, because its high latitude was once considered as the second constellation, because Cepheid variable star is an important standard candlelight when measuring distance, and Gouchen Chen-yi is deeply studied because of its close distance. In about 1900, its luminosity changes in a period of 3.97 days, and the average luminosity is about 0. 15 stars, etc. However, in the 20th century, the amplitude dropped rapidly. 1990s, the change was only 1%, and it remained at this level. In the same period, the average brightness of dog Chen Yi increased by 65,438+05%, and the cycle also increased by about 8 seconds every year.