I've seen it in a 4.25" f/10 Newt. On Mar 20, 2012 3:45 PM, "Siegfried Jachmann" <siegfried@jachmann.org> wrote:
In the 'Cloudy Night' double star chatroom claims have been made for the "pup" by a number of observers with telescopes as small as 80mm. Most of these observations are claimed by refractor users. Remembering how difficult it was in the 9" refractor, I am somewhat sceptical of the claims in an 80mm. I have not attempted it this season. I will try Friday night with a 160mm, weather permitting.
The suggestion of a device to produce diffraction spikes away from the pup is a good solution and has worked for me. My preference is a square mask over the aperture. You might also want to use a smaller aperture.
Sig
On Tue, Mar 20, 2012 at 3:25 PM, Chuck Hards <chuck.hards@gmail.com> wrote:
This is one of those instances where diffraction spikes may actually be helpful.
Spencer, if you can fashion a thin cardboard strip that you can place over your secondary/corrector plate, it will cause two diffraction spikes 180-degrees apart. The spikes will draw some of the glare off of Sirius A and if you rotate so Sirius B is 90-degrees to the spikes, it may help. 1/4" wide is enough.
If the upper atmosphere is at all in motion, however, it may be a lost cause. You need pretty steady seeing to see it. You may want to try as early as possible, as soon as Sirius is visible, even before dark.
On Tue, Mar 20, 2012 at 2:47 PM, Spencer Ball <spencer@spencerball.com
wrote:
Dave,
I have a Celestron 14" SCT. I have tried to place Sirius just outside of the upper left field of view (upper right before the star diagonal changes it) so I could see Sirius B without so much glare. But it doesn't work. It seems that I just must be picking all the wrong fuzzy days!
I'll try again. I see it has moved farther north than I had thought.
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