Re: (IAAC) Obj: NGC 6751 + small prism
At 04:44 PM 8/24/98 -0400, you wrote:
>Sorry been out of town for a few days.
>>Have you tried for the other bright planetaries in Aquila, NGC 6781 or
>Actually I have an observation of 6781 and 6803 to enter. I picked a couple
>of objects to enter that did not have any observations entered for them
>yet. Intestingly I have also been going after some of the fainter
>planetaries. Has anyone on the list used a O-III filter to verify some of
>the smaller planetaries ? Also I had the opportunity to use a special prism
>to find a very small planetary last week. It appeared to be three small
>prisms glues together like this ( ^ V ^). Does anyone have any details on a
>prism like this ?
It sounds like it is a direct vision prism, a very handy object to have for
planetary nebulae. It gives a spectrum in line with the axis so you look
straight through it instead of at an angle.
The easiest way to use it is to centre the object in the eyepiece, then hold
the prism between your eye and the eyepiece apeture. Look straight through
the prism. Keep your eye as close to the prism as to can manage without
sticking it into it. Where did you get it?
Nick Martin, Bonnyton House, By Ayr, Ayrshire KA6 7EW ,Scotland, UK.
Latitude 55 24'56" Longtitude 4 26' 00".
"Had I the heavens' embroidered cloths,
Enwrought with golden and silver light,
The blue and the dim and the dark cloths
Of night and light and the half-light, ....."
He Wishes For The Cloths Of Heaven by W.B. Yeats