03 Feb 2026
This is an image of NGC 6188. NGC 6188 is a colorful emission nebula located in the southern constellation Ara. It is known as the Rim Nebula, but is often called the Fighting Dragons of Ara.
This image is a narrowband image. Ionized gases in this nebula produce three prominent emissions: Hydrogen Alpha (656.3 nm), Sulfur II (672 nm) and Oxygen III (500.7 nm). I used the Hubble Palette to map these emissions to RGB image channels. These are as follows:
Red: Sulfur II (672 nm)
Green: Hydrogen Alpha (656.3 nm)
Blue: Oxygen III (500.7 nm)
Bottom line, this mapping communicates the composition of different regions in the nebula. It does not represent the way the nebula appears to our eyes.
Image processed by Andrew Macica, original data from Telescope Live.
Imaging Details:
Observatory: Rio Hurtado Valley, Chile
Telescope: Planewave CDK24
Aperture: 610 mm (24 inches), f/6.5
Focal Length: 3962 mm
Camera: FLI PL 9000 CCD
Filters: SII, H-alpha, OIII
Total Exposure: 25 hours 40 min.
Image Processing:
PixInsight 1.8.9-3 Ripley (x64);
BlurXTerminator, NoiseXTerminator, StarXTerminator (RC Astro);
Adobe Photoshop 25.12.4;
Adobe Lightroom Classic 15.0.1
Instruction on PixInsight from Adam Block Studios.
NGC 6188
17 credit
Filter | Avg Exp (s) | Total Exposure | Subframes |
|---|---|---|---|
| Halpha | 704 | 10h10m | 52 |
| SII | 553 | 7h50m | 51 |
| OIII | 541 | 7h40m | 51 |