Sunday, September 1, 2013

Image of Deneb and Sadr

This evening, at Canyon of Eagles, I imaged the region in Cygnus between Deneb and Sadr. This was the first test of my prototype DSLR cooling box.  After collecting data to test the performance of the box, I gathered 18 frames, each 300sec at ISO-1600.  I used the Canon 60Da and Canon EF 70-200/f4L lens zoomed out to 70mm and wide open at f/4.  In addition to cooling the camera, I took 4 dark frames at the end of the imaging session for calibration. I am still very pleased with this Canon EF 70=200mm/f4L lens.  Despite being a zoom lens, the image sharpness and quality are excellent.

The image shows the star Deneb (alpha-Cyg) at the top center which is the tail of the swan.  Then name derives from the Arabic word for tail. To the left of this star are the North American Nebula and Pelican Nebula. The star Sadr (gamma-Cyg), which forms the body of the swan, is at the center right. Just to the left of it is the Butterfly Nebula. At the bottom is the star Gienah Cygni (epsilon-Cyg) which forms the part of the eastern wing of the swan.

Northern Cygnus Region - Canon 60Da, EF 70-200/f4L, 18 x 300s @ ISO-1600, 70mm, f/4
With all of the foreground stars, it is a bit difficult to see the structure of the Milky Way.  From the article, Observing the Milky Way, Part II, in the October 2013 issue of Sky & Telescope, I get a better sense of some of this structure.  The bright patch below and to the right of Sadr is part of the Cygnus Star Cloud extending out to Albireo. This is the bright central portion of my earlier image. I understood from the article that this is looking down our own Orion-Cygnus branch. The dark area in the middle of the frame is the northern-most end of the Great Rift composed of obscuring dust. The North American and Pelican Nebulae are part of a closer OB association. I am not sure where to place the swath of the Milky Way extending down the center of the frame.

What is most fascinating to me is trying to grasp a perception of depth realizing that these structures are at very different distances and that we are seeing, not a flat plane of stars, but rather looking down corridors of space between spiral arm structures.  An animated 3-D projection would help enormously.

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