Patterns in the Sky
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Star Patterns in the Sky
- What are they? 88 currently
recognized patterns [There used to be other ones, no longer officially
recognized, like the XIX century Quadrans Muralis, after which
the Quadrantid meteor shower is named, or the Pleiades]; Are
they real groups of stars?
- Examples: Ursa major (with the
Big Dipper and Mizar); Cygnus; Lyra; Orion; Taurus; the Zodiac,
12 constellations (plus Ophiuchus!) along the Sun's path, the
ecliptic (2000 years ago).
The Significance of Constellations
- General idea: Humans observed
and named constellations because of their evocative shapes, to
keep track of the time of the year, as locations in the sky where
things happened, like planet-related events.
- Names of constellations: Chinese
constellations have names that represent palaces and gardens,
generals and ministers; In western culture the northern ones
are usually animals or mythical figures (southern ones can be
- Example: Aries and the "Star
- Why do constellations change?
At diferent times of the year, the Earth is at different points
along its orbit, and at night we face different directions.
- Examples: Scorpius in summer,
Leo in spring, Orion in winter.
in the Sky
- Planetary alignments: The ancient
Chinese believed that a planet conjunction was an omen of change,
based on the fact that astronomers saw a five-planet conjunction,
in the constellation Dongjing (Gemini), one year after the Han
Dynasty came to power in 605 BC; but alignments really have no
effect on Earth or Earthlings.
- The Zodiac: From "zodiakos
kyklos", the circle of animals along the ecliptic [12, Ophiuchus
having been discarded]; To understand the origin of names, must
realize that the Earth's axis has precessed over 2000 years.
- Lyra: Apollo's harp.
- Orion: The hunter.
page by luca bombelli <bombelli at olemiss.edu>,
modified 29 sep 2012