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ASHEN LIGHT!!!!!!!

Started by Kevin Barker, 08/30/2002 03:27PM
Posted 08/30/2002 03:27PM Opening Post
Well last evening my good friend and fellow astronomer (Larry Field)and I were observing Venus in very good seeing.
It was about 6 pm and Venus was high in the West perhaps 50 degrees altiude and decreasing.

We were viewing through thin cloud that was intermittent and extremely slow moving. Telescope was my Zeiss APQ 130/1000.
We were using a 6 mm Zeiss orthoscopic(166 X) with and without Schott glass filters Blue, yellow green, neutral density and green. We both saw subtle shadings and terminator intensity variations.

We decided to record and compare what each was seeing. Independently this was done. While I was finishing my sketch I was damned if I could make out the unlit edge of the planet continuing around 50 % of the unlit limb at the top and slightly less at the bottom.

It was unmistakable and best seen with the yellow green filter. I muttered this to Larry and he replied" I did not dare mention it but i could make out the faint outline of the rest of the disc"
We were trying not to interfere with each other's independence while sketching.

We swapped back and tried to see it in white light and when the disc was bright it did not show. But it was there when cloud partially obscured and acted as a filter.

Cloud then proceeded to blanket out our viewing.

Later we compared sketches and our sketches of dusky markings correlated well.

This is the fourth occasion I have observed the Ashen light.
It was barely perceptible this time. Other times I have observed with a C8 and my APQ 100/1000 and seen "The Ashen light".

Kevin Barker