AstronomyThe Walker School

An area of the sky, and contains all the stars and other celestial objects within that area.

The word is used colloquially to refer to asterisms: groups of stars that appear to form patterns in the sky.

Modern astronomy divides the sky into 88 constellations.

Constellations of the Northern Sky

Earth is sits fixed at the hub of the celestial sphere which contains all of the stars.

This is the simplest model of the universe, but problematic.

The apparent path of the Sun on the celestial sphere over the course of a year.

Incline to the celestial equator at an angle of 23.5 degrees

Declination (dec) is measured in degrees north or south of the celestial equator.

Right Ascension (RA) is measured in hours, minutes and seconds and it increases in the eastward direction.

Denotes an annual cycle of twelve stations along the ecliptic.

The zodiac is recognized as the first known celestial coordinate system.

Babylonian astronomers developed the zodiac of twelve signs

Includes a band of eight arc degrees above and below the ecliptic, and therefore encompasses the paths of the Moon and the naked eye planets (Mercury, Venus, Mars, Jupiter, and Saturn).

1. Specify their constellation.

2. Rank the stars in it in order of brightness.

3. Determine the celestial coordinates.

1. Where is your constellation located on the celestial sphere?

2. What other constellations border it?3. What are the brightest stars in your constellation? Make

sure to identify the alpha and beta stars.4. How many visible stars does the constellation have?5. Are these stars all the same distance from Earth?

Explain.6. What other celestial objects exist in your cluster? Give

some interesting facts about these objects.7. What role did this constellation play in mythology (i.e.

ancient culture)?8. Anything currently happening in this constellation (i.e.

within the last month)?