Spiral Galaxy NGC 6643 in Draco

This image was taken with an ST-6 CCD camera thru Kopernik's 20-inch F/8.1 Ritchey Chretien Cassegrain telescope. It is a 10 minute exposure. The field of view is about 5x7 arc minutes with East at the top.

Quote from Dreyer's New General Catalog (NGC):

"Pretty bright, pretty large, extended 50°, 2 stars westward."

NGC 6643 is a Spiral Galaxy in the constellation of Draco. It has a very small nucleus separated from the broken remnants of an inner ring that extends into a complex, irregular spiral pattern. Bright knots that are probably H-II regions outline the multiple spiral arms. Based upon published red-shift data, a rough distance estimate for NGC 6643 is 78 million light years. At that distance the diameter would be 86,300 light years.

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• NGC 6643
• Magnitude: 12.1
• Constellation: Draco
• RA: 18h 19m 46.2s
• Dec: +74° 34' 13" Epoch 2000
• Size (mins): 3.8' x 1.9'
• Classification: SA(rs)c II Spiral, Mixed Inner Ring - S-shaped, Luminosity Class II
  
  

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George Normandin, KAS

October 22nd, 2002