NGC 7822 (Sharpless 2-171)
HaRGB VERSION: Red enhanced by addition of about 25% Hydrogren alpha data. Also, the blue channel has been stretched to emphasize the reflection nebulosity present near the center of the nebula.
(click on image for larger size & full resolution - >3Mb):
Image acquisition and processing details:
| Telescope: | Takahashi Epsilon 180, f/2.8. |
| Mount: | Astro-Physics AP1200 German Equatorial Mount. |
| Camera: | SBIG ST-10XME cooled to -20C, internal guiding. All images binned 1x1. |
| Filters, Exposure Times: | HaRGB image total = 12hr 50min. AstroDon Red 160 min (16x10min), Green 130 min (13x10min), Blue 130 min (13x10min). Also 3nm narrowband filter: Ha 350 min (35x10 min). Additional data was obtained but discarded. |
| Dates: | Various 8/17/09-8/29/09. |
| Moon Phase: | Various. |
| Location: | Xanadu West Backyard Observatory. |
| Software: | CCD Commander, MaximDL, PinPoint, TheSky, FocusMax, CCDInspector, CCDStack, Adobe Photoshop. |
| Notes: | The red (including Hydrogen-alpha) channel is very dominant and thus images of this object usually do not show the purplish hue in the center. I noticed a fair amount of nebulosity present in the blue channel and decided to emphasize it by additional stretching in Photoshop. Although the data is real, this image may not be a"true" representation of the color of the nebula. |