perihelion

/per-uh-hee-lee-uhn, -heel-yuhn/US // ˌpɛr əˈhi li ən, -ˈhil yən //UK // (ˌpɛrɪˈhiːlɪən) //

近日点,近日线,近日轨道,近日点

Definitions

n.名词 noun

1
plural per·i·he·li·a [per-uh-hee-lee-uh, -heel-yuh]. /ˌpɛr əˈhi li ə, -ˈhil yə/. Astronomy.
- : the point in the orbit of a planet or comet at which it is nearest to the sun.

I'm not trying to calculate the perihelion of Jupiter or do 3D renderings of the National Cathedral.
The direction of the axis major of the orbit, which was found by calculating the longitude of the comet's perihelion.
The comet returned at the appointed time; and on the 12th of March, 1759, reached its perihelion.
At its perihelion it travels thousands of leagues per minute; at its aphelion it does not pass over more than a few yards.
The only sensible effect will be a secular motion of the perihelion.
The motion of Mercury's perihelion would therefore be 7´´ in the theory of Lorentz and 5´´.6 in that of Abraham.