Surely one of the most impressive PNs. Here is my sketch, Obsession 20", Southern Alps.
The inner part has been observed in a good, but not exceptional night, SQM 21.63. The colour of the PN was blue-greenish.
The halo has been observed, ten years later, on an exceptional dark night: SQM has been measured at 22.00 by two different observers with two different device. Such a value is totally rare in my observatory in southern Alps.
The color was blue, with no hint of green, estimated C130 / S30 in the usual concentration / saturation scale.
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