TucsonJim

By BikerJim

~The Big Dipper~

~In The Constellation Ursa Major~
~The Great Bear~


In North America the seven brightest stars in the Great Bear constellation are known as the Big Dipper, because the major stars can be seen to follow the rough outline of a large ladle or dipper. Though also know by many other names in different parts of the Northern Hemisphere.
The three stars that form the handle of the dipper from upper right are Alkaid, Mizar and Alioth. The four stars that form the cup of the dipper are, clockwise starting at the handle, and barely visible, is Megrez, then Dubhe, Merak and Phecda.
Mizar, in the handle, is actually an optical binary star, two stars very close to each other. They are known as the Horse and Rider. A good visual check of meteorological viewing conditions is to be able to see the second star in the binary with the naked eye.
The Big Dipper can be used to locate the North Star, Polaris, which is used for navigation. You can draw a line up from the two stars that form the pouring side of the dipper, Merak and Dubhe. Along that line and five times the distance between the two stars is the North Star.
Enjoy the sight for now, because the two stars at opposite ends of the dipper, Dubhe and Alkaid, are not part of the same star swarm that makes up the middle of the dipper. They are moving in a different direction then the other five stars. So, in a short amount of time the Big Dipper will no longer be recognizable, in an estimate 50,000 years.


Thanks for looking up!

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