Primordial Light: DEEP SKY Page 8
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The Gamma Cygni Nebula in Hydrogen Alpha, July 11, 2010

July 12, 2010. The central star is Gamma Cygni (γ Cygni), which is also known by its common Arabic name, Sadr صدر (breast in Arabic). Cygnus is the swan, and Sadr is the breast of the swan. γ Cygni is the star at the point where the vertical and horizontal members of the Northern Cross asterism in Cygnus intersect. The star cluster left of top center is M29. Takahashi TOA-150, SBIG STL-11000M in Hydrogen Alpha. This is the full frame from the STL-11000M. One hour (five x 12 minutes) integration time. All-Mac image. Click here for a larger version, also full-frame.

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The Gamma Cygni Nebula in Hydrogen Alpha, Wide View, August 6, 2010

August 6, 2010. This full-frame photo was made with a Takahashi FSQ-106ED astrograph, which has a field of view twice that of the TOA-150 that I used to make the top photo. The field of view in this image is 3.9 x 2.6°, about 10 square degrees, yet the photo still doesn't cover the entire Gamma Cygni nebula. This is a 50-minute exposure made over a period of several hours on the night of August 6-7 as I dodged clouds and haze. All-Mac image. Click here for a larger version, also full-frame.

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Details of the Veil Complex in Hydrogen Alpha, August 19, 2010

August 20, 2010. Above and below are segments of a wide-view photo of the Veil complex that I made with the Takahashi FSQ-106ED astrograph. This is a stack of six 10-minute exposures made on the night of 19-20 August, 2010. The segment above is known as the Witch’s Broom. All-Mac image. Click here for the full-frame.

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And Now for Something Different: M31 on 5-6 September, 2010
September 6, 2010. The sky was as clear and dark as I have ever seen it from my home observatory, so I stayed up until the wee hours to capture M31, the Great Galaxy in Andromeda. See a write-up on M31 with my earlier effort here. You may also click here or on the photo above for a larger version. All-Mac image. Nebulosity, PHD, TheSkyX Professional, Equinox 6, Photoshop CS3. SBIG STL-11000M CCD camera on a Takahashi FSQ-106. The mount is an Astro-Physics 1200GTO.
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Returning to H-Alpha: NGC 7000 on 24-25 September, 2010

My Hydrogen Alpha filter passes only a very narrow (3-nanometer) slice, or band, from the red part of the optical spectrum. Each time an electron in an atom changes energy levels, a photon is emitted. The band called hydrogen alpha is where interstellar hydrogen emits light when its electron jumps from a particular energy level to another particular energy level. The aesthetic benefit to amateurs is that light pollution and moonlight do not contain hydrogen alpha emissions. This enables me to make photographs such as this one through light polluted skies (though not through clouds, of course) and without concern for moonlight. There was a bright Moon in the sky when I made this photo. Professionals benefit both technically and aesthetically from the existence of the H-Alpha band. There is little or no black background sky in this photo; all of the dark areas are (vast) clouds of dust that obscure the bright nebula behind them. The dust and nebula together hide the background stars; practically every star that you see is between us and the nebula. NGC 7000 lies at a distance of 1,900 light years in the constellation Cygnus. This was to have been a 90-minute photo; airplanes and a guiding problem ruined three of six 15-minute exposures, so this is a 45-minute exposure rather than the planned 90 minutes. Takahashi FSQ-106, SBIG STL-11000M. Telescope, camera, and guider control with a MacBook Pro running Nebulosity, Pixinsight, and Photoshop. My first photo of NGC 7000, made three years earlier, is on this page. My latest photos of NGC 7000 are narrowband images.
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NGC 7000 yet again, a wide-field image of October 17, 2010

This is the full frame of a wide-field photo that I made with my SBIG STL-11000M camera and my Takahashi FSQ-106ED astrograph with a .73 reducer. Effective focal length was 387mm @ ƒ3.65. The field of View is 5° 19’ x  3° 33’. This image served as the component for the narrowband photos of NGC 7000 on the next page.
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