The Horsehead Emission Nebula IC434 is located in the constellation Orion. It was discovered in 1887 by French astronomers Paul-Pierre and Prosper-Mathieu Henry. They are actually two separate objects. The horse's head, in the foreground, is a dark nebula whose silhouette appears against the luminous 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 IC434 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 south of Alnitak. The Orion Nebula is not far away. Indeed, the constellation of Orion is a large complex, including in addition to these two nebulae, the Barnard loop. Located at a distance of approximately 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 L-eXtreme filter from Optolong. The color layer allows you to acquire the interesting hues of the flame nebula. As for the L-eXtreme filter, it brings out the alpha hydrogen of the emission nebula.
 
The processing, carried out entirely on PixInsight, is relatively complex. Indeed, this object has extremely luminous 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 coming 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 in bringing out the color palette as best as possible.