In Binary Systems containing one or more planets, if
ϕ
P
a
S
a
ϵ
<
0.75
, the planet's orbit is almost always unstable, where
ϕ
P
a
S
a
is the ratio of planetary semi-major axis to stellar semi-major axis, and
ϵ
is the stellar orbital eccentricity. However, when
ϕ
ϵ
=
0.25
, the planetary orbits appear to be stable. The Smithers Divide is this phenomenon, and is currently a topic of ongoing research at the University of California, Santa Cruz. It is named after Benjamin Smithers, a student at the University of California, Santa Cruz, California, United States.
