Explain the sidereal year, the tropic year, the ecliptic?

The actual time interval required for the earth to go around the sun, that is, when the sun and a star are at the same starting point, the time required for the sun to return to this position is only used for astronomy. A sidereal year is equal to 365.25636 flat solar days or 365 days, 6: 09: 09.504 seconds. The cycle of the earth's revolution is a sidereal year, which is the real cycle of the earth's revolution. In a sidereal year, as seen from the sun, the center of the earth starts from a certain point in the sky, orbits the sun once, and then returns to this point. If viewed from the earth, the center of the sun starts from a certain point (a star) on the ecliptic (the earth's orbit), runs until Sunday, and then returns to the same point (the same star). In a sidereal year, it takes about 6: 09: 13 seconds for the earth to rotate 360. The difference between the sidereal year and the tropic year is that the sidereal year is a movement cycle with a fixed point on the celestial sphere (such as a distant star) as the reference. Tropic of Cancer is the time interval when the sun center passes through the vernal equinox (or autumnal equinox, winter solstice and summer solstice) twice in a row on the ecliptic, that is, the time interval when the sun directly hits the Tropic of Cancer (or Tropic of Cancer) twice in a row. Therefore, the tropical year is also called the "season year". The tropic year is slightly shorter than the sidereal year, and its period is about 365 days, 5: 48: 46. The seasonal variation of the length of day and night, the height of the noon sun, the calendar arrangement of the solar calendar and the lunar calendar, and the division of the 24 solar terms all take the tropic year as the cycle.

Edit the relevant information in this paragraph.

Sidereal year: refers to the time required for the earth to revolve 360 degrees, 1 sidereal year = 365.2564 days = 365 days, 6 hours and 9 minutes 12.96 seconds. It applies to astronomy, not to calendars. Simply put; The sidereal year is the period of the earth's revolution, and the earth's revolution = 360. As shown in the figure; It is a sidereal year that the earth rotates counterclockwise from point A to point A. Tropic year: From the earth's point of view, the time for the sun to circle the ecliptic of the celestial sphere, that is, the time from vernal equinox to vernal equinox, is also called the solar year. 1 tropical year = 365.45438+09879 days = 365 days, 5 hours, 48 minutes and 45.456 seconds. Simply put; The tropical year is a four-season cycle, and the earth rotates.