Eta Carinae Nebula (NGC 3372)

The Eta Carinae Nebula (NGC 3372) is a is a large, complex area of bright and dark nebulosity in the constellation Carina. It is located in the Carina–Sagittarius Arm of the Milky Way galaxy.

The bright star at the center of the image is Eta Carinae. It is a system of at least two stars, the largest of which (Eta Carinae A) is around 100 times as massive as the Sun and 5 million times as luminous. Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. It is an excellent candidate for a supernova. (NASA Science)

This object is only visible in the southern hemisphere.

The previous image, in this album, is an LRGB image of the nebula. 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: 16 hours 50 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.