FreeLists / az-observing / [AZ-Observing] Re: I split Sirius tonight

["Richard Harshaw" <rharshaw2@xxxxxxx>]

Paul, I split the pair in the 1980's apestron with an 8-inch SCT using a
hexagonal objective mask.  The mask was made to fit just inside the retainer
ring, and the thickness of the mask at the vertices was about one inch, so
it was 6 inches in diagonal.  The mask breaks up the incoming light of a
central-obstruction telescope and piles it into six "spokes".  I rotated the
mask until two spokes bracketed the companion and there, with no diffraction
rings to mask it now, was the Pup.

Dick H


-----Original Message-----
From: az-observing-bounce@xxxxxxxxxxxxx
[mailto:az-observing-bounce@xxxxxxxxxxxxx] On Behalf Of Paul Lind
Sent: Sunday, February 17, 2008 11:56 PM
To: az-observing@xxxxxxxxxxxxx
Subject: [AZ-Observing] Re: I split Sirius tonight

Steve,

Way to go, fantastic.  You are the only person I know that has done this 
using a "small" scope.  Do you know anyone who has used an apodizing mask to

help separate Sirius' companion?  I think a rectangular mask has been used 
with the narrow dimension facing the companion.  I'm not sure how wide the 
mask opening should be, or whether it should be a series of wide slits.

Paul 

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