by Ann » Fri Oct 30, 2020 5:54 am
To really see the Witch Head Nebula, we need this orientation:
Can you see the Witch's protruding chin, her gaping mouth and her knobbly nose? And even perhaps her empty eye socket?
Wikipedia wrote:
IC 2118 (also known as Witch Head Nebula due to its shape) is an extremely faint reflection nebula believed to be an ancient supernova remnant or gas cloud illuminated by nearby supergiant star Rigel in the constellation of Orion.
...
The molecular clouds of IC 2118 are probably juxtaposed to the outer boundaries of the vast Orion-Eridanus bubble, a giant supershell of molecular hydrogen blown by the high mass stars of the Orion OB1 association.
What I would like to know is how nearby Rigel really is to the Witch Head Nebula. Clearly we are talking about a distance of many light years. Rigel is a bright star.
Note that while the Witch Head Nebula is a blue reflection nebula, it is not strongly blue. The bluest part of it appears to be around the nose and forehead of the witch, the central or middle part of the nebula. Perhaps the light from Rigel is not illuminating the other parts as strongly, or perhaps there is dust between us and the nebula in front of parts of the Witch Head, diluting the nebula's blue color.
Take a look at Bob Franke's picture of the Witch Head. There are clearly patches of brown dust in the nebula's "chin".
Ann
To really see the Witch Head Nebula, we need this orientation:
[float=left][img3="IC 2118, the Witch Head Nebula. Photo: Scott Rosen."]https://lh3.googleusercontent.com/proxy/hY4sNT5eItnZV_wv91WwyOv5ZgG4O3hu_kOkSJym85MxDEFTc1atoeR9oSYw9TBy4bEc2qJ4tO437EdGVnxifXivGST4ONMGsPW1BhEP5x8aRpkjnAFNFH6DNpfyoLl3JKD4Dh6a3Fb8fwSuS8AB4yI817BXq2IxO8k5KQL-yco8PSB8o1Zm6r72uJyowvGaxc91eugw[/img3][/float] [float=right][img3="The Witch Head's face. Photo: Bob Franke."]https://skyandtelescope.org/wp-content/uploads/ic2118BobFranke.jpg[/img3][/float]
Can you see the Witch's protruding chin, her gaping mouth and her knobbly nose? And even perhaps her empty eye socket?
[float=left][img3="Orion constellation with Rigel and the Witch Head Nebula (bottom right).Photo: Rogelio Bdernal Andreo."]https://upload.wikimedia.org/wikipedia/commons/thumb/4/47/Orion_Head_to_Toe.jpg/800px-Orion_Head_to_Toe.jpg[/img3][/float]
[quote][url=https://en.wikipedia.org/wiki/IC_2118]Wikipedia[/url] wrote:
IC 2118 (also known as Witch Head Nebula due to its shape) is an extremely faint reflection nebula believed to be an ancient supernova remnant or gas cloud illuminated by nearby supergiant star Rigel in the constellation of Orion.
...
The molecular clouds of IC 2118 are probably juxtaposed to the outer boundaries of the vast Orion-Eridanus bubble, a giant supershell of molecular hydrogen blown by the high mass stars of the Orion OB1 association.[/quote]
What I would like to know is how nearby Rigel really is to the Witch Head Nebula. Clearly we are talking about a distance of many light years. Rigel is a bright star.
Note that while the Witch Head Nebula is a blue reflection nebula, it is not strongly blue. The bluest part of it appears to be around the nose and forehead of the witch, the central or middle part of the nebula. Perhaps the light from Rigel is not illuminating the other parts as strongly, or perhaps there is dust between us and the nebula in front of parts of the Witch Head, diluting the nebula's blue color.
Take a look at Bob Franke's picture of the Witch Head. There are clearly patches of brown dust in the nebula's "chin".
Ann