NGC 6946 Spiral Galaxy in Cepheus

My first observation of NGC 6946 was in October of 1992.  I was using my 10-inch reflector, at 57x from my backyard.  My notes were very brief:  Faint and large with low surface brightness. Once found, easy to see. October 4, 1994, 10-inch @ 114x:  A triangle of three bright stars to the south.  The surface brightness is very low, and a brighter nucleus was noted.  Several faint stars could be seen superinposed in the galaxy, and the edges fade very gradually.  At low power the galaxy appears as little more than a faint glow, with a mostly round shape. October 26, 1994, 10-inch reflector at 114x:  Very large and easy to see.  I do think that spiral structure could be seen during the last observing session. There have been many other observations since 1994, always looking for the spiral structure that I had noted during an earlier observing session. September 29, 2011:  Observing from a dark site in the South Mountains, about 20 miles north of my home in Boiling Springs, North Carolina.  I was observing with Steve Davis, my good friend and observing partner of many years.  He brought a 14.5 inch reflector, however, the skies and transparency were very poor, due to high moisture.  The NELM was very close to 5.0, possibly a bit less.  When using 108x, the galaxy was fairly easy to see, oval in shape, with a brighter, more concentrated middle.  However, with the poor sky conditions, there was no trace of spiral structure.  We were both disappointed.  On a good night this site would allow for a NELM of 7.0 or better. October 2, 2011.  The following sketch was made from my moderately light polluted backyard. 

My 10-inch presented the galaxy as fairly dim, with a brighter and more concentrated middle, with quite a few faint embedded stars.  With careful viewing, and spending almost two hours looking at this galaxy, during fleeting moments, I could finally, at last confirm spiral structure.  A spiral arm could be seen with averted vision, coming out of the east side and curving south.  There were other areas of spiral structure noted almost throughout the galaxy, however, this was very difficult, and was fleeting at best.  After nineteen years of attempting to confirm spiral structure, I was both excited and pleased.  It had been a long wait, but for sure worth it. Roger Ivester

Advertisements
Explore posts in the same categories: Uncategorized

%d bloggers like this: