Interesting. The areas arrowed as red emitters are precisely the areas where I have seen red with scopes of 32-82cm. However, those areas never appeared crimson. The color I've always seen is more like a "dusty rose" or a "red-tinted gray" and only one area near the Huygenian region has exhibited a "slight peach hue" or a "pale peach-gray" color. The predominant color has never been the red--it's full-spectrum gray. But, the only area where I've seen a "green-only" hue is in the central region. The fainter outer areas could have been a rose hue diluted by a pale greenish emission. While M43 and nearby NGC1977 have appeared a pale bluish-gray when color has been visible. And that's another thing--the amount of color visible has changed from night to night. Some nights of exceptional transparency show more color than other nights. I've always seen more color when the nebula was higher in the sky and the SQM gave a darker reading. If the appearance of color was a threshold issue, that would be consistent with my previous observations. Also consistent with a threshold observation is the fact that larger apertures always make the colors more apparent. I'm looking forward to seeing what an Ha filter will show. I also have nebula filters with and without a red broadcast, so I'll be interested in seeing what obtains with each. I have eyepieces that produce exit pupils of 5.4mm, 3.8mm, 3.0mm, 2.3mm, etc., so I'll also be able to test the visibility of colors at various exit pupils. Unfortunately, due to work, I will not be able to do this test until the new moon period in January.
-------------------- Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie
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Re: Is it possible to see the nebula with colour?
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