The name 'Yed' comes from the Arabic word for 'hand': Yed Posterior and the nearby Yed Prior
represent either the left and right hands of the Serpent Holder Ophiuchus, or two parts of
one hand. This hand-star is known as the 'Posterior' because it crosses the sky about
four minutes behind Yed Prior.
A view of the Yed Posterior system. In the foreground is Epsilon Ophiuchi B,
a small and faint 'satellite' star, invisible from Earth. The system's much more
massive and luminous primary is seen here in the distant background.
Though they appear close in the sky, the two Yeds are really some considerable distance apart.
Yed Posterior is about 108 light years from the Earth: Yed Prior is 62 light years further
still. The intervening space is occupied by a small white star, BSC 6067, that is invisible
to the naked eye.
Yed Posterior is a yellow, G-type star, which means that its structure and chemistry are
similar to those of the Sun. There are differences, though: Yed Posterior is several
hundred degrees cooler than the Sun, and very considerably larger.
This is a binary system: Yed Posterior's companion is relatively distant from the main
star (at least 3,500 AU). It is also very faint, with an apparent magnitude of just +12
as compared to the main star's +3.2.
With Yed Prior, Yed Posterior shares a small
square patch of sky that connects the body of Ophiuchus with its
neighbouring zodiacal constellation,