Small Magellanic Cloud (SMC), Irregular Dwarf Galaxy (NB)

The Small Magellanic Cloud (SMC) is an irregular dwarf galaxy that is gravitationally bound to the Milky Way Galaxy. It is 210 KLY distant. It can be observed naked eye from the southern hemisphere. It is located in the constellations Tucana and Hydrus.

The previous image is an LRGB image of the SMC. An RGB image has a mapping that closely corresponds to the colors in our visual perception.

This image, on the other hand, 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).

A formula is used to assign pixel values to RGB channels. The purpose is to more closely emulate the classic Hubble Palette. The specific palette I used is the Foraxx Palette.

(PixInsight Forum)

The color mapping, for this image, is as follows:

Red: (OIII^~OIII) * SII + ~(OIII^~OIII) * Ha

Green: ((OIII*Ha)^~(OIII*Ha))*Ha + ~((OIII*Ha)^~(OIII*Ha))*OIII

Blue: OIII

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: Heaven's Mirror Observatory, Yass, Australia

Telescope: Takahashi FSQ-106ED

Aperture: 106 mm (4.17 inches), f/3.6

Focal Length: 382 mm (with 0.73x focal reducer)

Camera: QHY 600M Pro CMOS

Filters: SII, Ha, OIII (SHO)

Total Exposure: 9 hours 35 minutes

Image Processing: PixInsight 1.8.9-3 Ripley (x64);

BlurXTerminator, NoiseXTerminator, StarXTerminator (RC Astro);

Adobe Photoshop 25.12.1;

Adobe Lightroom Classic 14.2

Instruction on PixInsight from Adam Block Studios.