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The WHAC Meeting was held on April 10, 2007 in the Hualalai conference room at Keck Headquarters in Waimea.

Doug Summers facilitated the club meeting. He opened the meeting with a hearty welcome to all members both new and old. Those new to WHAC were asked to introduce themselves to the club. There were about 35 members in attendance, about a half-dozen were new faces.

Dan "The Pizza Man" presented our regular feature The Sky This Month. Dan is self-professed "crazy about astronomy" and did a nice job sharing what's up with the night sky! First, he demonstrated a neat trick to illustrate whether the Moon is waxing or waning. The scribe cannot put this into words adequately…please see "Da Pizza Man" for a repeat performance. Dan used planetarium software to illustrate the location of a number of prominent objects. We are slowly losing Orion in the west, but M42 is still around. The Pleiades are also slipping further west as the curtain is beginning to close on all the winter constellations. Dan illustrated the location of M81/82, the pair of galaxies in Ursa Major. Saturn is high overhead at dusk, providing excellent views of that ringed world.

Craig Nance presented The Astrophotography of Jonathan Burnett. In March Craig visited Jonathan during a trip to Florida. Jonathan has visited Hawaii and went to a WHAC observing session and attended a meeting long ago. Jonathan is one of our numerous mainland WHAC members; persons who have participated in WHAC events during their Hawaiian vacations, and follow our goings-on from afar. Jonathan had been sending Craig increasingly spectacular images over the past 1 to 2 years. Craig happened to be in Florida and was able to pay Jonathan a visit. Craig showed pictures of Jonathan's gear. Suffice to say, it is very impressive. This was followed by the heart of the presentation, showing a spectacular collection of wide-field images of the night sky. Awesome!

We then took a break for a bit of socializing, enjoying the coffee, tea, and snacks, and to look at three large telescopes, which were the featured part of the rest of the meeting.

The main program of the evening was by Olivier Guyon, an amateur astronomer/telescope builder who is part of the Subaru Observatory AO team. He spoke about his telescope Priscilla. Priscilla has had many forms over many years. It has a 19.1" clear aperture (let's call it 20") at f/4.9. The mirror was made in Ireland over a decade ago. Olivier detailed how the telescope evolved from initial efforts to build a large, permanently mounted telescope in France, to a trailer mount in Hilo, to its present lightweight design which uses carbon fiber.

Olivier then presented his work on building a truly large, but ultra lightweight, amateur telescope. He envisions building a 40" (1 meter) telescope of about f/2 to f/3 focal ratio. The mirror would be extremely thin, only about 1/4" thick! This would require an active mirror control scheme. To make the blank, Olivier is putting the finishing touches on an oven to slump a 40" piece of 1/4" plate glass into the proper meniscus shape. Olivier spent a bit of time detailing and showing pictures of the oven. His oven will get to 800 degrees Celsius, the slumping temperature for the plate glass. It only requires several 500 Watt halogen lamps. But, since the oven is highly insulated, this is all the power that is necessary. He expects to begin test slumping of smaller blanks in the coming weeks. Olivier plans to use a water jet technique for mirror polishing and figuring. This is a slow process, but he believes it is do-able with a computer controlling the process. The telescope would have an active control system to maintain the proper shape of the primary mirror, much like the large Mauna Kea telescopes.

Craig Combes and Doug Summers spoke about their large telescopes as well. It was entertaining to see these three large telescopes, all having different approaches.

Doug concluded the meeting with WHAC business. There will be observing sessions both Friday April 13 and Saturday April 14. The Friday session is primarily for home school students, with participants gathering at the club dark site at 6pm. The Saturday dark site session will be the first-ever WHAC hot dog cookout. Recall that the club plans to organize a social like this once every season. Doug asked for and got a volunteer to purchase the food. Everyone will gather starting at about 5pm for food, socializing and telescope setup. A second group of school kids will join the festivities at ~7pm on Saturday night as well.

Craig Nance briefly mentioned that AstroDay is coming on April 21. He mentioned that slightly over a half-dozen people volunteered to bring telescopes to the VIS that evening. Craig will coordinate the AstroDay particulars with the telescope volunteers directly.

The next WHAC meeting is Tuesday May 8, 2007 in the CFHT large conference room at 7pm. The meeting agenda will be on the WHAC web site soon. The traditional pre-meeting dinner is at 6pm at the Parker Ranch Food Court.