[sac-board] SAC Meeting Minutes: 2011/04/08

  • From: Paul Dickson <paul@xxxxxxxxxxxxxxxxx>
  • To: SAC-Board <sac-board@xxxxxxxxxxxxx>
  • Date: Sat, 9 Apr 2011 05:45:20 -0700

Chris Hanrahan opened the meeting at 19:34.

Announcements were:

* Randy Peterson passed away about 3 weeks ago.

* May 7 will be Astronomy Day and our Thunderbird Public Star party (34th 
annual event).  There also be an event at the Arizona Science Center.

* Chris Hanrahan will be acting treasurer for the night.

* Special thanks to AJ Crayon for the Messier Marathon.  The award will be at 
the next meeting.

* Also thanks to Jennifer Polakis who distributed snacks at the marathon and 
collected donations for Randy Peterson's family.

There were 3 visitors and new members at this meeting: John, Steven, and Adam.

Jack Jones had flyers for the May 7 public star party what members could post 
and hand-out.

Steve Dodder reminded everyone that he was the chairman of the Novice Group and 
about the 50/50 raffle.  The North Rim session of the Grand Canyon Star Party 
is now full.

Paul Lind had two images from the ATM/Astro-Imaging meeting that took place at 
his house on the Tuesday before the club meeting.  Lynn Blackburn had his 
refurbished Schaefer mount with GoTo and home-made pier.  Rick Rotramel had his 
dobsonian scope with Early-American legs.

JD Maddy had images of the moon, comparing the sizes of the moon with it's 
recent close approach with previous images.  He also has images of the 
Whirlpool galaxy, Pleiades, Rosette, and more.

Jim Riches had images and videos to show of his past work.  His website is 

Dean Ketelsen had a display at the back of the room to view the stresses within 
glass, even your own eye glasses.

Steve Coe reminded us to feel free to interrupt kibitzing at star parties.  We 
are always happy to discuss something new.  Steve told us he is now finished 
astro-imaging and showed us his final attempts.  Steve is going back to visual 
observing.  Paul Lind reminded Steve that he had stated 15 years ago that he 
was done with astrophotography.

The break started at 20:16 and lasted until 20:45.  Tom Polakis continued the 
meeting by introducing Dean Ketelsen from the Stewart Observatory Mirror Lab.  
Dean is now retired but is now working as a Technical Expert.  His topic was 
"the ABC's of the GMT and LSST at Stewart Observatory Mirror Lab".

The LSST is the Large Synoptic Survey Telescope (http://lsst.org).  It's a 8.4m 
mirror with two radii figured into it (the primary and tertiary mirrors on one 
piece of glass, 8.4m f/1.18 & 5m f/0.83).  The telescope will have a 3.5 degree 
field of view.  The camera will have 3200 megapixels with 30 TB of data 
captured each night.  It will take 15 second exposures which can reach down to 
magnitude 24.  The data from the survey will be available in near real time 
(currently the fiber link to Chile would require 24 hours to transfer 12 hours 
of captured data.

The GMT is the Giant Magellan Telescope (http://gmto.org) that will have 7 8.4m 
mirrors, 6 of which are off-axis figures.  The off-axis mirrors will have a 
14mm aspheric departure (meaning if you rotated the mirror around its center, 
the height would change up to 14mm as the mirror was turned).  The GMT would 
have the equivalent of a 24.5m (80 feet) primary mirror.

Dean gave showed off Roger Angel's latest project, this solar power.  More info 
can be found at http://rehnu.com.

Dean also has a blog at http://theketelsens.blogspot.com.

The meeting ended at 21:55.

        -Paul Dickson

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