Monday, May 13, 2019


Well, I've done it; I moved the 20" scope into the roll off shed.  I have high hopes of getting the most out of this scope, since I observe most from home.  My dark sky scope will be the 30" Challenger, and my 10" Springsonian.  Will see how I like it.

First use of the scope was Friday night, and first view was the moon.  The scope tracks like a dream!  Seeing was a bit soft and there were thin clouds, but the view was really nice.  The nearly first quarter moon was moving through M44 the Beehive Cluster that night.  The west coast missed most of the occultations but I did catch one.  I centered on the star and watched the moon, dark side leading, slowly approach the star.  The moon's movement became easier to see as it got closer to the star.  Finally, the star just blinked out. 

I used the 8" off axis mask for some sharper views, and binoviewed the moon for a while.  Then I moved to some doubles in Leo but I had a strange aberration: bar shaped stars.  Likely astigmatism but it did not change direction inside or outside of focus.  I wonder if it is thermally induced, since I cooled with a backside fan and then turned out the side boundary layer fans at the start of observing; it's possible the mirror was unevenly cooled.  I'm thinking now of getting a fan suspended over the primary...  Will need to have this issue resolved.

More cloudy weather the next ten days; very frustrating observing environment.

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