What constellations have the same position?

Is the constellation fixed in the sky?

For the horizon coordinate system (elevation angle, azimuth angle) and the first equatorial coordinate system (time angle, elevation angle), the position of the constellation is constantly changing, because it is related to the revolution of the earth. For a celestial body, its horizon coordinates and the first night coordinates are constantly changing (one sidereal day is a period).

For the second equatorial coordinate system, the galactic coordinate system, the position of the constellation will not change, because the constellation is an artificially defined sky area. If the position of the constellation is still changing, what's the point of specifying the constellation? Constellations are prescribed for the convenience of research, and they are still turning every day. What's the use of formulation? However, the coordinates of the constellation will change, and for the second equatorial coordinate system (due to precession and nutation; It's not so much the constellation that moves on the celestial sphere as the vernal equinox, which depends on how you choose the frame of reference), and so is the galactic coordinate system (because the solar system revolves around the Milky Way, it can be regarded as the celestial sphere revolving around the Silver Road, and it can also be regarded as a guide revolving around the celestial sphere, which is also a relative movement). But the relative position of the constellation on the celestial sphere will not change, otherwise the reason has already been said. What is the purpose of making the constellation?

The answer on the first floor answered half of what I said above.

The netizen on the third floor is reading my reply in the west-the purpose of making a constellation.

The netizen-constellation on the fourth floor is artificially designated. For celestial bodies in the Milky Way, the redshift is far less than self-motion, which can be completely ignored, while galaxies outside the river are far away and cannot move once on the celestial sphere for hundreds of thousands of years.

The netizen on the fifth floor-you mean self-reliance, indeed, it is by no means used for tens of thousands of years now, but what is the purpose of constellation making-if he changes every day because of his tiny self-reliance, what's the point of making him? The International Astronomical Union may change the definition of constellation positions in the next few thousand years, but the relative positions of all constellations on the celestial sphere will not change until the new definition appears.

Speaking of initiative, I want to say a few more words. Due to the motion of celestial bodies, their positions on the celestial sphere are constantly changing. Tens of thousands of years later, the current constellation will definitely change beyond recognition. At this time, the International Astronomical Union will definitely redefine the rules about the location of constellations.

The above may be a bit confusing, because my language is not very good and there are many technical terms. If you don't understand, please discuss it separately.