- River (Wikipedia)
A river is a natural freshwater stream that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth.
- Rigil Kentaurus (stars.astro.illinois.edu)
RIGIL KENTAURUS (Alpha Centauri) with PROXIMA CENTAURI (Alpha Cen C). Among the most famed stars of the entire sky, surely rival in renown to Sirius and Polaris even though not visible to much of the world’s population, is the “foot of the Centaur,” Rigil Kentaurus, “Rigil Kent,” the first star of Centaurus, probably much better known as Alpha Centauri or just Alpha Cen.
- Proxima Centauri (Wikipedia)
Proxima Centauri is a small, low-mass star located 4.2465 light-years (1.3020 pc) away from the Sun in the southern constellation of Centaurus. Its Latin name means the ’nearest [star] of Centaurus’. It was discovered in 1915 by Robert Innes and is the nearest-known star to the Sun. With a quiescent apparent magnitude of 11.13, it is too faint to be seen with the unaided eye. Proxima Centauri is a member of the Alpha Centauri star system, being identified as component Alpha Centauri C, and is 2.18° to the southwest of the Alpha Centauri AB pair. It is currently 12,950 AU (0.2 ly) from AB, which it orbits with a period of about 550,000 years.