perihelion

n.

近日点；

复数：perihelia

1. A comet is at perihelion when it is closest to the sun.
   彗星最接近太阳时，它就是在近日点。
2. The anomalistic year is the time between successive transits of the Earth through the perihelion.
   近点年是地球连续两次通过近日点之间的时间。

Post-perihelion observations of water in comet Halley
Mercury's Perihelion from Le Verrier to Einstein by N. T. Roseveare
On the recently determined anomalous perihelion precession of Saturn
Activity of comets at large heliocentric distances pre-perihelion
Photochemistry of Pluto's atmosphere and ionosphere near perihelion
Photometric behavior of comet Hale-Bopp (C/1995 O1) before perihelion.
The NASA Infrared Telescope Facility Comet Halley Monitoring Program II. Post-Perihelion Results
Excess open solar magnetic flux from satellite data: 1. Analysis of the third perihelion Ulysses pass
Optical Observations of Comet Hale-Bopp (C/1995 01) at Large Heliocentric Distances Before Perihelion
Solar quadrupole moment and purely relativistic gravitation contributions to Mercury's perihelion advance