IC 434 Horse's Head

The Horsehead emission nebula is located in the constellation of Orion. It was discovered in 1887 by French astronomers Paul-Pierre and Prosper-Mathieu Henry. They are actually two separate objects. The Horsehead, in the foreground, is a dark nebula whose silhouette appears against the bright background of the emission nebula. However, they are part of the same molecular cloud. The Horsehead nebula is also complemented by the Flame nebula NGC 2024.

The Horsehead nebula can be recognized with the naked eye in the starry sky because it is located at the level of Orion's belt and more precisely to the south of Alnitak. The Orion nebula, for its part, is not far from there. Indeed, the constellation of Orion is a large complex, including in addition to these two nebulae, Barnard's Loop. Located at a distance of about 1000 to 1500 light years, this complex of gas clouds fills almost the entire constellation.

The image presented is the result of two very distinct mosaics: the first is in color, captured with a zwo 533mc camera while the second results from an Optolong L-eXtreme filter. The color layer allows to acquire the interesting hues of the flame nebula. As for it, the L-eXtreme filter allows to bring out the hydrogen alpha of the nebula in emission.

The processing, carried out entirely on PixInsight, is relatively complex. Indeed, this object has extremely bright stars, including Alnitak, which must be reduced while preserving them. The mixing of the different layers is also delicate in order to obtain a result revealing the colors of the flame nebula from the color layer and the Ha layer of the filter. It is therefore necessary to create and play with different masks in order to obtain the desired result. In the end, PixInsight's NBRGB Combination process was very useful to bring out the color palette at its best.

Equipment used:
- Skywatcher 80ed Evostar
- ZWO 533mc pro
- ZWO 120mm mini
- ZWO AM5
- Asiair plus
- EFW
- EAF
- OAG
- L-eXtreme Optolong filter
- Stacked with Siril and PixInsight
- Processed with PixInsight
- Finished with Lightroom