NGC 891 is an excellent example of an edge on spiral galaxy. Our own Milky Way galaxy would probably look like this if we could view it from the side. Prominent in this image is NGC 891's dark dust lane running the length of the galaxy, as well as the large central bulge typical in spiral galaxies.
Also visible in this image are two dwarf satellite galaxies. One is about 1/2 way out from the galaxy core on the left top of the galaxy, and the other is just to the right of the central bulge. There are also about a dozen background galaxies scattered thoughout the image.
NGC 891 is relatively close to us at a "mere" 30 million light years distant. As such, its apparent diameter in a telescope is fairly large - about 13' long by 2' tall. For comparison, the Full Moon is about 30' in diameter.
In this image, North is Up. This image is cropped to 70% of the original full frame.
Exposure Details |
Lens |
Celestron C-8 SCT with Celestron focal reducer |
Focal Length |
1260mm |
Focal Ratio |
f/6.3 |
|
Mount |
Schaefer GEM - 7 1/2 Byers Gear |
Guiding |
80mm f/11 guidescope with PHD Guiding |
|
Camera |
Canon 450D - Gary Honis modified |
Exposure |
190 subexposures of 180 seconds each at ISO 1600 - 9 1/2 hours total |
Calibration |
30 darks, 30 flats, 30 bias |
|
Date |
December 20 and 24, 2011 |
Temperature |
35F on 12/20, 43F on 12/24 |
SQM Reading |
|
Seeing |
3 of 5 on both nights |
Location |
Pine Mountain Club, California |
|
Software Used |
Images Plus 4.0 for camera control, calibration, stacking, digital development, and multiresolution smoothing. Photoshop CS5 used for flat fielding, levels and curves, color balance, high pass filter, star shrinking, saturation adjustments, and noise reduction. Carboni Tools for additional saturation adjustments and noise reduction. HLVG for additional color correction. |
Notes |
Although the seeing conditions were fair on both nights, I was very pleased with the fine detail I was able to capture in this image. |