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Nebulous region (also known as NGC 3372) around the star Eta Carinae, in hydrogen alpha light.

This giant diffuse nebula is one of the largest H II regions (ionized hydrogen gas) in our galaxy.  Eta Carinae itself is a very peculiar star, having varied widely in brightness in the past.  At one time in 1843, it was the brightest star in the sky after Sirius.  It is thought to be among the most massive and luminous stars in our Milky Way, at more than 100 solar masses.

This image is a mosaic of 4 frames taken through a filter that only passes light within a narrow range of wavelengths around 656 nm - characteristic of ionized hydrogen gas.  The height of this mosaic extends about 2 deg of sky - 4 times the diameter of the full moon.


Image info

Telescope:  Celestron 9.25" Schmidt-Cassegrain at f/6.3

Focus:  Prime focus

Filter:  Astronomik Hydrogen Alpha 13nm FWHM

Mount:  Vixen GPD with Skysensor2000

Camera:  Modified Canon EOS 300D, at ISO800

Guiding:  700mm refractor guidescope, SAC7 camera, autoguided with Guidedog software

Exposure:  Total 75 mins (25 x 180s), 2 x 54 mins (18 x 180s) and 36 mins (12 x 180s)

Date:  9th & 19th March, 19th & 30th April 2005

Processing:  RAW file conversion, Offset and Dark subtraction, flat fielding, registering and stacking done in IRIS.  Only the Red channel was used.  Curve stretching and mosaic in Photoshop CS.  Noise reduction in Neat Image.




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