Constellations

http://www.hope.co.nz/projects/stars/stars_ss_dx_org.jpg

What is a constellation?

A constellation is a group of stars that are connected together to form a figure or picture.

• The term is also used to mean any group of stars visibly related to each other

• Considered as a fixed configuration or pattern in a particular culture.

• The International Astronomical Union (IAU) divides the sky into 88 official constellations with exact boundaries, so that every direction or place in the sky belongs within one constellation.

• Northern hemisphere- constellations based upon the constellations of the ancient Greek tradition, containing the signs of the zodiac

http://www.fas.org/irp/imint/docs/rst/Sect20/map3+.jpg

http://www.astropix.com/IMAGES/C_SPRING/BIGDIP.JPG

• A star pattern may be widely known but may not be recognized by the International Astronomical Union; such a pattern of stars is called an asterism.

• An example is the grouping called the Big Dipper.

• The grouping of stars into constellations is essentially arbitrary and random

• Different cultures have had different constellations, although a few of the more obvious ones tend to recur frequently, e.g., Orion and Scorpius.

• In space, most of the stars we see have little or no relation to one another, but can appear to be grouped in the night sky.

•The stars in a constellation rarely have any astrophysical relationship to each other; they just happen to appear close together in the sky as viewed from Earth; they typically lie many light-years apart in space. One exception to this is the Ursa Major.

http://joemorris.mystarband.net/images/Orion%20Constellation.jpg

Some well-known constellations contain striking and familiar patterns of bright stars.

Examples: Orion (containing a figure of

a hunter) Leo (containing bright stars

outlining the form of a lion)

Scorpius (a scorpion)Crux (a cross).

http://www.astropix.com/HTML/WIDE/CONST16.HTM

http://www.astropix.com/HTML/WIDE/CONST03.HTM

http://www.astropix.com/HTML/WIDE/CONST09.HTM

http://www.astropix.com/HTML/WIDE/CONST10.HTM

http://www.astropix.com/HTML/WIDE/CONST14.HTM

http://www.astropix.com/HTML/WIDE/CONST17.HTM