Sunday, December 27, 2015

backyard work

Yesterday morning I worked on my roll off shed, redoing the wire connections on the differential thermostat.  I am sure the connections are correct now, but the system still doesn't work -- the fan did not come on, nor did the light bulb light.  I will need Harry's help to figure it out.

The sun had cleared the neighbor's pine tree so I installed my solar filters and had a nice look at sunspot complex AR2473.  It had quadrupled in size in the last couple of days and had been threatening a coronal mass ejection.  There was one giant spot which appeared like a honeycomb section, with seemingly straight sides.  Trailing away from it were multiple small spots and disruptions, configured roughly as two triangles.  I scanned around and found AR2472, which was one small distinct spot with its mate visible with averted vision only.  I could not find AR2470 or AR2475.  The image at 277x was turbulent but usable.

The weather was to be very clear that night so I opened the shed before dinner and set a fan behind the primary.  I wanted to be sure the image problems I have been having were due to the atmosphere and not an un-equalized primary.  I continued my many weeks project of aligning the equatorial platform, tracking some stars at meridian and to the west.  Toward 10:30pm I decided close was good enough, and bolted down the platform.  I was able to track in declination for 10 minutes, and the right ascension errors I was seeing I think were due to mount speed errors.  The set-up should be good enough for my purpose, which is astrometry of double stars, and general observing of the planets, moon, and so on.  Maybe even some short exposure astrophotography or lucky imaging of double stars.

After bolting down I turned the scope to Rigel, which had cleared the tree, and was happy to see I could split it well -- though I did not see clean airy disks.  I next moved to the Trapezium and could just see the E and F components, but again the image was not clean.  The sky seemed pretty steady but maybe there was some turbulence up there to blame.  But ever since I had this mirror tested and learned it is overcorrected (and has a turned edge which I fixed by masking off the outer 1/2 inch of the mirror) I have been concerned about whether this mirror is the best quality to have spent the effort to mount in an observatory, and whether I will be able to do the astrometry I have planned.  It's merely a good mirror, not a great one...  I'm hoping for some truly steady nights to prove it one way or another.

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