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Equatorial delight

3 July 2009

After looking again through the boxes that my new tripod/mount came in, I stupidly realised that I actually had all the parts. That tricky foam packing with its little nooks and crannies!

So naturally I put the whole thing together and stood back to admire it sturdy heftiness, before remembering that I had a Baader solar filter I still hadn’t tried and astronomical sunset doesn’t occur until almost 21:30 local. Seemed like a good opportunity for a twofer, so I attached my 5″ OTA for the first time and took the it outside onto the front porch, where the sun was still well above my local horizon.

Attaching the solar filter was easy. It slid over the end where the dust cap goes, preventing unfiltered sunlight from entering the OTA, and fastens with 3 grub screws to ensure it doesn’t come loose. After I had done this I looked into the eyepiece socket (without an eyepiece) and pointed the scope at the sun until the view became brilliant, then attached the 25mm wide angle eyepiece and was rewarded with a lovely off-white image of the entire sun in the field of view. I tried the other eyepieces, though didn’t bother with the 2X Barlow, and used the fine-adjustment RA/Dec knobs on the mount to scan the edge and surface of the sun. Never look at the sun directly.

Unfortunately, the surface of the sun wasn’t particularly interesting because:

  • We’re in the sun’s 11 year solar minima cycle — and this cycle is particularly deep and quiescent — so there aren’t many sunspots to be seen.
  • Correspondingly, there isn’t a great deal of solar flare activity to be seen. Which is good news for the astronauts in low earth orbit.
  • The wavelengths of light seen via a solar filter provide a white image with little contrast. This can be addressed with an appropriate filter… that I don’t currently have.

What I did see was the sun up close and safely (that in itself is noteworthy) and I did see its boiling surface, particularly at the edge. Some of it would have been due to earth’s atmosphere, but there was enough there to make it enjoyable.

So the next immediate challenges are to learn how to use the equatorial mount correctly (despite inheriting an inexpensive one when I was a teenager, I never learned how to set it up properly), including the formidable setting circles, and to make the most of the plentiful summer sunlight by getting a filter that will enable more detail to be seen.

This is fun!

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