Trip to Chile, May 2012

Wide field view of one the most shining H-alpha complex of the Southern hemisphere.

Object information

Wikipedia Eta Carinae (η Carinae or η Car) is a stellar system in the constellation Carina, about 7,500 to 8,000 light-years from the Sun. The system contains at least two stars, one of which is a Luminous Blue Variable (LBV), which during the early stages of its life had a mass of around 150 solar masses, of which it has lost at least 30 since. It is thought that a hot supergiant of approximately 30 solar masses exists in orbit around its larger companion star, although an enormous thick red nebula surrounding Eta Carinae makes it impossible to see optically. Eta Carinae is enclosed in the Homunculus Nebula, itself part of the much larger Carina Nebula. Its combined luminosity is about five million times that of the Sun and has an estimated system mass in excess of 100 solar masses.It is not visible north of latitude 30°N and is circumpolar south of latitude 30°S. Because of its mass and the stage of life, it is expected to explode in a supernova or even hypernova in the astronomically near future.

Processing details

Pre-processing with DSS

No offset nor dark nor flat applied. Lights integration under sigma clipping method (kappa=2, 5 its)

Processing with PixInsight

BackgroundNeutralization (thr=0.15), then crop (dead border lines)

ColorCalibration

HistogramTransformation

Star mask generation on luminance with ATrousWavelets (7 layers, all kept active except R) and Morphology (dilatation 60%)

Star size reduction using Morphology (starMask active, erosion 100%)

Nebula mask generation on luminance with ATrousWavelets (7 layers, only R kept) + HistogrmTransfo (s=0.0790, h=0.7386, m=0.7143)

LHE mask generation with PixelMath (=Min(inv(star),neb))

De-burning nebula core with HDRMultiscaleTransform (6 layers, deringing active, nebulaMask active + stretched to work only on core)

Contrast enhancement with LocalHistoEqualization (radius=100, limit=2, amount=0.8, lheMask active)

Noise reduction with ACDNR (using lightness mask: m=0.28, s=0.28, h=0.78), then SCNR green+blue 100%

Saturation boost using CurvesTransformation (1st step with luminance mask, 2nd step with nebMask)

Final HistogramTransformation to correct black point only.