November 21, 2009: DSR, how dew I love thee

Greg LaFlamme

I made the decision to try DSR late Saturday afternoon. The idea of observing had been passed around but I really had no intention of going out. By mid-day, NOAA and the CSC looked pretty good. My mind changed:-) Mark Wagner, Olga Stackovsky and Mark Johnston were going so why not. I knew there was going to be a dew problem because the difference between the forecasted temperature and dew point was something like 20 degrees! I'm brave and I'm armed with a new 12v blow dryer, I figured I'd go ahead and risk it. Overall the night was great. The sky was fairly dark, Mark Johnston's SQM readings were around 21.30. Transparency was 5/7, seeing was 5/7 as well but varied enough to allow the use of very high magnification most of the time. Finding objects, enjoying eye-candy and hopping through galaxy groups was made easy by the relatively clean sky. The Crab was detailed and gorgeous! Dew yew want the bad new?. The dew was tenacious! It was all up in my business. Everything rained. I had to use my blow dryer constantly! Only my primary mirror remained clear, everything else was dripping or fogged over. Mark Wagner and I do not have any dew management devices (but thats going to change rapidly) and we both got nailed. The secondary in my new 22" is a dew magnet and fogs over as fast as the eyepiece does. Mark Johnston has all kinds of heater-goodies on his Starmaster and remained happy the entire night. He took a moment and educated me on heaters. Thanks buddy:-) By 12:30, I ran into electrical problems with my 12v supply system and gave up. I made the repairs today and am confident that shouldn't happen again. I'm also researching various ways of heating my secondary mirror as well as my finder and eyepiece. I'll make a simple system that attaches to my scope quickly should that dirty-dew become an issue again. I woke up this morning in the back of my truck, nice and comfy however the 18" of my partially exposed sleeping bag was frozen and crunchy:-) I whooped up my usual coffee and oatmeal breakfast then started packing up slow. Just as the sun peaked over the hills and warmed my face, a huge blanket of clouds snuffed out any hopes of bringing home dry equipment. The morning was beautiful though and I really enjoy early morning conversation with my pals, old and new. I had some serious clean-up to do and I repaired my 12 volt woes.

Update: Thanks to Mark Johnston, Leda 1889183 and 1889390, I was again able to test my Tak LE 5mm against another sample of a 5mm T6 Nagler. The results were consistent with what I discovered last week. The Nagler shows the faintest of averted-vision galaxies a tad better than MY Tak LE. I am so surprised by this. My testing was done without a Paracorr at a magnification of 402x. The testing took around 20 minutes of careful observing and switching eyepieces to be confident and certain. The background sky seemed equally dark in both eyepieces however the Nagler made the galaxies just a tad brighter, increasing the size of their halos and better defining their position angles. The absolute defining factor was made by judging the averted-vision galaxies below.

Leda 1889183, mag 16.8 was seen with 50% averted vision in the Tak LE but could be held directly in the Nagler. Leda 1889390, mag 17.4 is a 20% averted vision object in the Tak but could be seen 50% or more in the Nagler.

I know... weird.

Thanks again to Kevin Ritschel for the hospitality and huge sky!

GML