Staring @ the Sun, 25

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2/2/2011: A Grab n'Go Solar Kit: Ever since I got back from Tennessee last October, I have not had a chance to sungaze. Trees. Once the Sun moved south of the celestial equator, the yard has been hopeless as a Sun-observing venue. The Sun is still weeks away from coming back into view from any of my usual or otherwise handy locations. But it's spending a little longer every day between the tops of a few inconvenient conifers and the edge of the house. So from about 1:00 in the afternoon until 2:00, I can take a peek if I maneuver between the shadows.

There was this LDX55 / Autostar mount down in the basement which I bought on clearance from Meade many years back thinking of cobbling together some goto pieces for the G11. That project was utterly superceded by the adoption of an A-P Mach1. But that LDX55 still has possibilities. It was originally sold with telescopes as large as a 10-inch F4 Schmidt-Newtonian (I think that was ludicrously ambitious for that mount, but it's telling that some thought the load was plausible). I've been told it works well under 6-inch OTA's and sometimes under larger ones, so I figured it would have no problem with a 60mm sunscope. I even have a "hypertune" kit for it here somewhere if this proves promising.

But first, there was making a mounting rail, wiring up a power supply (I refuse to buy D-cells by the dozen and my rechargeable Tenegra's offer only 1.2v each rather 1.5v; a trial run with them was not fun), and fitting the mount onto a Gitzo tripod (because it's smaller than stock, known to be solid while carrying the 5" refractor and Giro XL in NM, and because there are more than enough tripods standing around here already).

And here's how it works:

OK, now see here's the rub. I wanted a nice solar photo here. We'll try again the next clear spell. I carried the telescope and mount into a sunny spot north of the house and got a good look.

On the computer screen, I saw filaments and a couple of active regions and some prominences, but when I tried to line up on the best, brightest areas, I found that the hand control could nudge the telescope N, S, and W very smoothly, but moving it E was almost impossible. The field moved, then rubber-banded almost back to where I started. Some sort of wildly over-enthusiastic backlash compensation, I imagine. For every degree I moved, at least nine tenths were taken back, first at high speed then slower until the field was pretty much as it was. It didn't matter how fast I slewed. While coping with this, clouds returned and I had no images to show for this first effort.

Online, I found that the cure involved training the drive. Not calibrating the motors. Not resetting: "Training the drive" in Az/RA. I set up indoors, made another oak adapter to put a white light telescope on the mount, focused on a Christmas tree ornament hanging at the far end of the back lawn, and "trained the RA drive."

On the one hand, it's a pain to have to do this. On the other, it;s simple enough and it worked! Clear skies are forecast for Sunday, three days hence. It's just as well that I have some time because I am out of practice with the Chameleon's software.


For reference, here's the (or "a") recipe to get the LXD55 tracking and available for fine motion control without lots of unnecessary commotion (alignment, goto, targets... bah!):

    1. Power on
    2. Dismiss Sun warning: press 5
    3. Dismiss offer of detailed instructions: press Enter
    4. Accept displayed date: Enter (or optionally, set it)
    5. Accept displayed time: Enter (or optionally, set it)
    6. Daylight Savings Time: Enter (or change setting)
    7. When prompted to "Align" hit MODE until "Align" is replaced by "Target" then down arrow to any astronomical target.
    8. Press and hold MODE for a few seconds. Release.
    9. Display shows RA/Dec. Press a number key to select a slewing speed.
    10. You're in business.


2/6/2011: The promised solar photo with the LXD55 mount:



See technotes on the next photos.
Color added in PS CS4


2/13/2011: After a computer meltdown and recovery, I checked and found a large, growing, and complex sunspot nearing the solar meridian. Time to play with new toys and tools. I got lucky:



Active Region 1158 glowing brightly a little less than 1 hour
after the start of an M6.6 flare, the most powerful of the current cycle.
Click here for larger image
or here for a colorized one.

Lunt LS60Ha DS50, barlowed. Point Grey Chameleon
Best 150 of 300 frames stacked and sharpened with Registax 5.1

2/15/2011. Twin Peaks. The M-flare above was the Cycle 24 record holder for a little more than a day. In the early morning of 2/15, UT, the same active region produced an X2 flare, the most powerful since 2006. It was tough to photograph with the entire bulk of the Earth in the line of sight, but here's the GOES X-ray record:




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                   © 2011, David Cortner