- Achird (stars.astro.illinois.edu)
ACHIRD (Eta Cassiopeiae). At almost fourth magnitude (3.44) and faint to the eye, and not a part of the traditional outline of Cassiopeia, Achird is often neglected.
- Tributary (Wikipedia)
A tributary, or an affluent, is a stream or river that flows into a larger stream (main stem or “parent”), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they flow, drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean.