Friday, December 17, 2004

The Seven Sisters



No doubt this is the star cluster Mozart had in mind when he wrote "...like a diamond in the sky." Only about seven of these stars are visible to the naked eye, hence the nickname "The Seven Sisters".

More properly known as The Pleiades, they are often referred to as The Little Dipper, and the asterism does in fact resemble a dipper but the actual Little Dipper is far away in the northern sky. Astronomers know these gems as M45, from the Messier catalog.

The Pleiades are now believed to be traveling through a dense cloud of cosmic gas which is being illuminated as the blue stars pass by, giving them their blue halos, the diamond sparkle that Mozart sang to.

I took this film picture last night, a one-minute exposure with 70mm lens F4.5 @400. A good picture of M45 shows much greater detail and beauty but I'm ashamed to display one so here's a link instead:

http://antwrp.gsfc.nasa.gov/apod/ap021201.html

-- Dalton Hammond

More of my Backyard Astronomy

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