English

Noun

apohermion ‎(plural not attested)

1. (astronomy) Apoapsis around Mercury.
   • 2013 June, Guan Le, Peter J Chi, Xochitl Blanco-Cano, Scott Boardsen, James A Slavin, Brian J Anderson, & Haje Korth, “Upstream ultra‐low frequency waves in Mercury's foreshock region: MESSENGER magnetic field observations”, in Journal of Geophysical Resarch, volume 118:

     MESSENGER is in an orbit of 80° inclination, with apohermion occurring in the southern hemisphere at 7.1 R_M (R_M is the radius of Mercury) and perihermion in the northern hemisphere at 1.1 R_M, and the orbital period is 12h.