Due to its appearance, IC 2118—also known as the Witch Head Nebula—is a dim reflection nebula thought to be an old supernova remnant or gas cloud lit up by the supergiant star Rigel nearby in the constellation of Orion. The nebula is located 900 light-years away from Earth in the Eridanus Constellation. The Witch Head's blue tint is a result of the nature of the dust particles, which reflect blue light more effectively than red light. According to radio measurements, parts of IC 2118 emit a lot of carbon monoxide, which is a sign of the presence of molecular clouds and star formation in the nebula. In fact, deep within the nebula, some classic T-Tauri stars and candidates for pre-main sequence stars have been discovered.
The Orion-Eridanus bubble, a massive super shell of molecular hydrogen blasted by the high-mass stars in the Orion OB1 association, is likely adjacent to the outer limits of the IC 2118 molecular clouds. The supershell enters the interstellar medium, creating ideal conditions for star formation. One such place is where IC 2118 is situated. The bright reflection nebula's cometary structure and wind-tossed appearance strongly point to a close relationship with the high-mass luminous stars of Orion OB1. Strong evidence in favour of such linkage comes from the fact that the cometary cloud heads of IC 2118 point northeast towards the direction of the association.
The witch head nebula rises in front of the constellation of Orion (while not part of the constellation), situated in the lower corner of the constellation.
The picture is V1 of the top part of the Witch Head Nebula. The overall Nebula will most likely be a 3-piece mosaic, but the picture here is of the upper part of the nebula comprising 1 hour 30 mins of data at 30-sec sub-exposures, stacked in DeepSkyStacker and processed in PixInsight.
The picture is V1 of the top part of the Witch Head Nebula. The overall Nebula will most likely be a 3-piece mosaic, but the picture here is of the upper part of the nebula comprising 1 hour 30 mins of data at 30-sec sub-exposures, stacked in DeepSkyStacker and processed in PixInsight.
Processing the data was quite straightforward, including Denoise, Automatic Background Extraction (ABE), star removal and stretching the curves, all while keeping the background dark. This was done using masks.
- Scope – Celestron RASA 8
- Mount - Skywatcher EQ6 R Pro
- Guide scope – ZWO 30mm
- Guide Camera – ZWO ASI 120mm mini
- Main Camera – ZWO Asi 533mc Pro
- Control box – ZWO ASIAIR Pro
- Filter – Baader 2" UV/IR filter
- Starizona Filter drawer next to the camera sensor
- Fox Halo 96k power bank
- Dew heater with its own power bank on the guide scope
- Main scope Celestron ring dew heater powered though the ASIAir