Monday, October 1, 2012

Cleaning the 30" Mirror

When I received the 30" Obsession a few months ago, the mirror was a little dusty.  Ordinarily, I let dust go a while, as it doesn't have a discernable impact on viewing.  After I traveled down some horribly dusty roads on the way to Iowa Star Party, I was shocked to discover that a pretty heavy layer of dust had managed to get inside the trailer, and some even on to the mirror.  So, by this time, the mirror was looking pretty filthy.

Tonight, I decided to take on the challenge of cleaning this beast.  This mirror weighs over 200 lbs, so removing it from the mirror box, is really impractical.  If you've seen Dave Kriege's old Obsession videos, you've seen his demonstration on cleaning a 25" mirror, INSIDE the mirror box.  Of course, the scope he was cleaning, was bare bones, had no electronics.  My 'Anzio Annie' has all sorts of circuitry running through the rocker supporting the mirror box, which would quickly be destroyed, should it be exposed to water.

My solution, was to simply run a tarp below the mirror, with the mirror box tilted such that the mirror was perpendicular to the ground.  Any water I poured over the mirror, would fall onto the tarp and roll out the back of the mirror box, on to the ground, and well away from the electronics.

Like Kriege's recommended cleaning procedure, I just added a drop of unscented, Dawn dish detergent, to a gallon of distilled water.  For rinsing, I filled an atomizer bottle with distilled water.  For wiping grit off the surface, I used sterile surgical cotton balls from a local pharmacy.  An even better option would be sterile, surgical rolls of cotton, however, I could not find any at local stores.  I'll order some online for the next time around.

So, the cleaning process just involves, pouring the (hardly noticeably) soapy distilled water across the surface of the mirror.  Further wetting down with the atomizer, I took a bunch of cotton balls in my hand, and carefully slide them across the surface to pick up loose debris.  No force needed to be applied, accept carefully where a piece of grit didn't come off easily.

After wiping down with the 'soapy' water, I poured another jug of clean distilled water across the mirror surface to rinse.  Distilled water is such, most of it just sheets down and off the mirror.  For the few drops that remain, I use a virgin micro fiber cloth, using only the weight of the cloth itself to pick them up.

The result, was a beautifully shiny Russian primary mirror.  I generally don't clean a mirror more than once per year.  It's just not worth it, the less one touches their polished mirror, the better.

Happy 50th Anniversary Omaha Astronomical Society

Saturday night, this past weekend, the OAS held a banquet celebrating it's 50th anniversary. It was a wonderful evening, with some 85 members/guests coming out. Thanks to our outreach chairman John Johnson and his wife Robin for putting the event together. We had a fantastic line up of guests, including several returning past members. A 'roll call' of past presidents was taken (of which, many were present), w
ith long time member and past president, George Allen being recognized with 'lifetime member' status. We had some special guests from outside the club as well, including Prairie Astronomy Club member and UNL Mueller Planetarium director Jack Dunn, Astronomical League President, Caroll Iorg was on hand to present a certificate recognizing the occasion, and Astronomy Magazine senior editor, Michael Bakich, who gave an entertaining talk on the history of amateur astronomy. Here's to the next 50 years!

Friday, September 21, 2012

The Iowa Star Party

Last weekend I attended one night of the Iowa Star Party.  Unfortunately, while the night started out nice, a thin haze settled in, leaving less than desirable observing conditions.  The night did give me an opportunity to continue working out operations of the ServoCAT/Argo Navis on the, still relatively new to me, 30" Obsession (affectionately dubbed, 'Anzio Annie').  I continue to get more proficient at setting up the scope by myself.  It is somewhat amazing, that this massive instrument can be setup be a single person.  The next opportunity I'll have for darker skies, is the Heart of America Star Party, occurring in the middle of October, and hosted by Astronomical Society of Kansas City.  The Iowa Star Party itself is a wonderful event.  A more intimate atmosphere, ISP draws perhaps 25-30 amateur astronomers.  A Friday public night drew another 75 or so, members of the public.  Saturday evening, a banquet is held, followed by a speaker from one of the local universities.  This year featured Iowa State professor, Curtis Struck, who gave an informative presentation on colliding galaxies.  I had hoped to attend ISP Thursday through Saturday.  Maybe next year.

Shot of 'Anzio Annie', just prior to tear down, on Sunday morning.

The Great Atlas of the Sky

I ordered a copy of Piotr Byrch's Great Atlas of the Sky today.  The atlas is on sale for only $99 (originally $260) and may well be discontinued. Billed as the 'world's largest atlas of the entire sky', the Great Atlas is indeed massive. Comprised of 296 maps, each covering 15° x 10° of the sky. Each map is 24 x 17 inches.  Over 2.4 million stars are plotted down to magnitude 12, along with over 70,000 galaxies, clusters, and nebulae. Coming from Poland, the atlas will take some two months to produce/ship.  I'll provide a review when it finally arrives!