If we measure the amount of time between two equinoxes, it ends up being 21 minutes shorter than a sidereal year.
如果我们测量两个春分点之间的时间量，最终会比恒星年短 21 分钟。
PBS太空科学
That means if we based our calendar on sidereal years, the seasons would quickly get out of sync, Christmas would end up in July, dogs and cats, living together, mass hysteria!
The amount of time it takes a star or constellation to reach the same point in the sky at the same time of day is 365 days 6 hours 9 minutes 9.76 seconds, or a sidereal year.
A sidereal year (from Latin sidus "asterism, star") is the time taken by the Earth to orbit the Sun once with respect to the fixed stars. Hence it is also the time taken for the Sun to return to the same position with respect to the fixed stars after apparently travelling once around the ecliptic.
It equals 365.25636 SI days for the J2000.0 epoch.
近义、反义、联想词
近义词
n.
year, sidereal time
英英词典
sidereal year n.
the time for the earth to make one complete revolution around the sun, relative to the fixed stars