NGC 7000, The North American Nebula, and IC 5070, The Pelican Nebula
Ha-OIII-SII (5 nm) Narrowband Version: Colors mapped using Red=SII, Green=Ha, Blue=OIII
(click on image for larger size & full resolution - about 13Mb):
Image acquisition and processing details:
| Telescope: | Takahashi Epsilon 180, f/2.8. |
| Mount: | Astro-Physics AP1200 German Equatorial Mount. |
| Camera: | SBIG STL-11000M cooled to -20C, external guiding with SBIG e-Finder and ST-402ME cooled to -15C. All images binned 1x1. |
| Filters, Exposure Times: | HaRGB image total = 14hr 10min. AstroDon H-alpha 470 min (47x10min), OIII 180 min (18x10min), SII 200 min (20x10min). All narrowband filters with 5nm bandpass. Additional data was obtained but discarded. |
| Dates: | Various 05/03/10-05/23/10. |
| Moon Phase: | Various. |
| Location: | Xanadu West backyard roll-off roof observatory, in Tucson, AZ. |
| Software: | CCD Commander, MaximDL, PinPoint, TheSky, FocusMax, CCDInspector, CCDStack, Adobe Photoshop CS4. |
| Notes: | This image is "false color"; the 3 different narrowband filters were
assigned to red, green, and blue channels to create a color image that
emphasizes differences in emission in various parts of the nebulae.
In human vision, hydrogen-alpha would actually be in the red realm,
rather than green as depicted here. SII is also in the red region,
and OIII is closer to green. The color mapping here is based on
the mapping used for images produced by NASA for Hubble Space Telescope
data, and is thus called "The Hubble Pallet". The Hubble team
tends to tone down the greenish hue by mixing the data with different
weights. Basically what this all means is that these nebula would actually appear the naked eye as more reddish than greenish. |