Two frame mosaic of the Orion sword area including the Orion nebula (M42) and the Horse Head nebula (IC434). Image shown at 25 % of the original size
Equipment: Takahashi FSQ106 scope. ASA DDM85 mount. SBIG STL11000 camera. Narrowband filters (SII; H alpha, and OIII)
Location: Pozuelo (Madrid)
Date: January and february 2011
Exposure: 24 hours, 48 unguided subexposures of 30 minutes
A false RGB palette was used for color processing as follows:
Red channel: H alpha data plus SII data
Green channel: OIII data
Blue channel: OIII data plus 15% of H alpha data to simulate the effect of the H beta emission line in the blue region of the spectrum
In this way, emission line data were employed to provide colors according to their location in the spectrum, thus simulating an image obtained with broadband red, green and blue filters