by Marek Cichanski
It's 2:30 in the morning, and I'm standing inside a cottage, dressed in full winter regalia, holding an XT12 OTA in my arms, sweating and straining as I hold its ass end next to the fireplace, trying to un-dew the PRIMARY.
Okay, now that you've had a chance to wipe the coffee off your monitor, after the spit-take, and now that you've had a chance to change your unexpectedly moist undies (after laughing so hard), here's... (Paul Harvey voice)... the REST of the story...
After the first of my 'nights of the emu' on Friday 9/2, a weather system arrived. David and I had been able to observe until about midnight, and then some high clouds rolled in, which turned out to be the harbingers of another big frontal system sweeping across the Southern Ocean and southern Australia. The beauty of going Down Under during the austral winter, though, is that the nights are so long. Even with a midnight cloud-out, we got in 5 hours of observing, which is as long as a full night at Shingletown.
David drove back to Sydney on Saturday the 3rd for a conference, and I had four more nights by myself out at Coonabarabran. Saturday night was rained out. Although I'd been using the CPT, David had been using a 12" Guan Sheng dob provided by the owner of the cottage where we were staying. (This is essentially the same thing as an Orion XT12. I think that Guan Sheng makes these for a variety of people, including the Binocular and Telescope Shop in Sydney, which is where this particular scope came from, I think.) I decided that I'd give the 12" a try, so I spent Saturday night center-spotting the mirror and dealing with some finder bracket issues, as the rain beat against the cottage's metal roof. For some reason, one of the Australian channels had the McNeil-Lehrer News Hour, and I watched the grim saga from New Orleans unfolding on the small screen as I worked on the scope and listened to the rain.
Clouds still hung around on Sunday, and I went for a hike in the Warrumbungles. Didn't get rained on, but I knew that it would take some luck if the sky was going to clear.
I was sitting around eating dinner at about 6:30, only a half-hour before astro dark, when the sky cleared like a shot. Ack! It's GO TIME!
Washed dishes, took stuff outside, set up the scope, all as fast as I could. I looked as busy as the proverbial one-legged man in the ass-kicking contest. It was violently dewy, stuff looked like it had been hosed down as soon as it was set up. I Enjoyed some nice views of Omega Cen and Cen A, and then went after a few members of the Centaurus galaxy cluster. I think I saw NGC 5011 and NGC 5026. Clouds rolled back in around 10 pm. I slept until midnight, saw that it was still mostly cloudy, slept until 2, then got up and saw that it was clear enough to take a shot at the Magellanic Clouds. For this, I was able to set up just outside the cottage, but when I did, I saw that the PRIMARY had dewed up! And that was down at the bottom of what was essentially an XT12 rolled steel tube. The fact that I'd left the 12v muffin fan on for 'cooling' probably had something to do with this. Sometimes, there's such a thing as too much thermal equilibrium.
Oh, man! What am I going to do, I thought? How in the world can I get some heat on this primary? Then an idea hit me, born of desperation... The cottage had a fireplace of sorts in it. Actually, it was what Aussies call a 'woodheater' - an enclosed fireplace with a glass door, which burns the wood inside a metal box, and vents the smoke up through a chimney pipe. (It's enclosed in a brick chimney, and isn't freestanding like a Franklin stove.) It turns out to be a very nice arrangement. Once you get the fire going, you can burn a large piece of eucalyptus wood almost all night if you turn the air intake down. When you want to heat the room, you switch on a fan that circulates air around the hot firebox and blows it out into the room. (BTW, this eucalyptus wood was amazing. It was a dark reddish-brown underneath the light-colored bark, and it was as dense as depleted uranium. Not easy to get it to burn unless you already had a good bed of glowing coals, but once lit, it would crank out BTUs galore for hours.)
Ever been out on a cold night of Bay Area observing, and wished you had a 'warming hut'? That's essentially what we had, and it was wonderful. I'd come in from the cold, open up my coveralls, sweater, and fleece suit, and let the hot air jet into my clothing. Better yet, when I got tired of a chilly winter breeze on the back of my neck, I'd sit on the floor in front of the fireplace, switch on the fan, and let the hot air hit me right on the back of the neck. That's got to be about the best feeling you can have with your clothes on. Then I'd go to the kitchen, make a hot English muffin and a hot cup of tea with sugar and milk, and fortify myself for another couple of hours of observing.
So, it occurred to me that I might have a shot at salvaging the rest of the night if I could get some of that hot fireplace air onto the primary. Aha, I realized, that's where the 'cooling' fan comes in. So, I picked up the OTA, hauled it inside, and after much straining to hold it up in front of the woodheater, I got it cleared. Oh my garden of roses, what a job of work. Fortunately, I was laughing as I did all this, fully aware of how absurd it all was. I was wishing that I was sitting around a picnic table at Calstar, telling the story to a crowd of TACos. "So there I was..."
That's what happens when you go far far away to observe. If it were Montebello or Fremont Peak, I'd just go home. If it were Calstar, I'd just crawl in my tent and go to sleep. But when you've flown 7000 miles to observe, every minute counts. Stuff like this was totally worth it. Small price to pay for pristine austral skies.
(Fortunately, I DID have my Kendrick heaters, and I'd found a 12vDC battery pack at a Wal-Mart metastasis in the town of Mudgee, so I was okay for most of my dew-busting needs.)
But, snakebit as the night was, it still wound up being about a 5-hr night, which I call a success. The next night was sort of a repeat, with a sleep session in the middle of the night due to fatigue. Had to bring the scope in again, this time to un-dew the secondary and ParaCorr. This time around, though, I realized that I could set the OTA on the floor and un-dew it with the little forced-air space heater that I'd found in the closet. Much better...
To my chagrin, though, the otherwise-perfect sky turned into a mackerel sky around 3 am, thus cutting my LMC session short. Oh well, ho-hum, another 5-hr. night, can't complain too loudly. There's one more night to go...
Posted on sf-bay-tac Sep 08, 2005 23:07:22 PT
Converted by report.pm 1.2 Mar 12, 2006 14:40:19 PT