The term binary minor planet (BMP) is used for minor planets
that have binary companions, e.g., (natural) satellites. The name suggests
some degree of equality, but the term is commonly used for any minor
planet for which a satellite is observed. Since the term
"minor planet" is used for very small objects
(anything larger than a meteoroid), there is some logic to this.
Over 600 binary asteroids are known,
the first whose binary nature was discovered being 243 Ida
in 1993.
Gaia uncovered a significant number.
Several binary trans-Neptune objects (binary TNOs) are known as well.