[ATM] Misc. topics

[Mike Lockwood <melockwo@uiuc.edu>]

Hi,

This message is a bunch of random things I wanted to post....

First, I've posted a new image taken with Bob Holmes' 32" F/4.  It is 
of the Hercules cluster Abell 2151.  Go here and click on the "Images 
from the 32" F/4 link" and it's the first images:
http://bi-staff.beckman.uiuc.edu/~melockwo/telescopes/holmes32/holmes32.html

We've largely solved the alignment problems of the telescope, and the 
limiting magnitude has dropped dramatically.  Bob has confirmed 
asteroids of magnitude 21.8 using five minute exposures.  This meets 
his goal for the telescope, and we suspect it can go deeper.  I think 
this experience bodes well for the use of BVC in larger sizes, so long 
as the blank is checked to make sure it meets mechanical tolerances 
for thickness and wedge.  (I also believe it has a thermal advantage 
over Pyrex, but I don't have any data to support that assertion yet.)

Second, I've posted a new strain testing image for a 25" blank.  It is 
at the bottom of this page:
http://bi-staff.beckman.uiuc.edu/~melockwo/mirror_making/strain/strain.html

This is a blank we had considered slicing, but I don't believe that 
would be wise given all the striae it contains.  By the way, Advanced 
Glass Industries can handle slicing blanks this size.

Third, I wanted to briefly plug a couple of star parties happening 
here in Illinois.  I'm planning to attend the Illinois Dark Sky Party 
September 21-24th, and the Prairie Skies Star Party Sept 28-Oct 1st. 
On Friday at Prairie Skies I'll be doing a Foucault testing 
demonstration (I'll be testing mirrors that people bring), and later 
that day we'll do a telescope "walkabout" to look at the various 
amateur scopes on the field.  Prairie Skies is held at Camp 
Shaw-was-nas-see, the former site of Astrofest.  IDSP is held at a 
fairly dark state park west of Springfield.  It is darker than Prairie 
Skies or Astrofest.

Links to the events can be found here:
   http://www.prairieskies.org/
   http://www.sas-sky.org/star%20party%202006/star%20party%202006.htm

Lastly, if you're interested in buying a 24" F/5 blank or a 24" flat 
blank (both 2" thick Pyrex) please contact email me off list.

Mike Lockwood
http://bi-staff.beckman.uiuc.edu/~melockwo/index.html


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