Saturday, October 19, 2019

#233 - Friday, October 18, 2019 - Refinements

Since the Heart Nebula went behind my plum tree sooner than I thought it would last night, I adjusted the sequence to end the Heart a little earlier, and then I have it jumping back to the Pacman Nebula until NGC 2174, the Monkey Head Nebula, is high enough to image.  Sometime soon I'll figure out how best to map my backyard's horizon, and then at someday I'll look into some scheduling software...with so many clear nights, I'm constantly adjusting the times in my sequence to keep up with the ever-sliding timing of targets!  Oh well, that's what seminars are good for, getting things done on my computer... :D

I noticed while watching the sequence last night from inside on my desktop that the initial gotos before centering were quite a ways off, so I re-added a few alignment and calibration stars.  I also un-ticked the "Sync" box in the Plate Solve tab of Sequence Generator Pro, since I wondered whether that was causing the issues with M42 and M31 not tracking after the meridian flip.  The mount only likes to be synced on one thing at a time, and I'm not sure if SGP handles that right for Celestron mounts.

I watched the Pacman Nebula center in SGP, and the RA offset was stuck at around 200 pixels and wouldn't improve!  So I re-added another alignment star, which helped get it closer, but it still wouldn't get lower than 65 pixels.  So finally I just turned off centering and let the sequence run.

On the second round of the Pacman Nebula, after the Heart went behind the tree but Pacman had emerged in the north, I saw in the SGP log the next morning that it failed to meridian flip, but I don't know why!  I decided I would re-align the scope from scratch (rather than re-adding alignment stars) the next night.

I still got some tree in the first Pacman Nebula sequence -- I really need a way to map out my yard!  It would make setting up the sequence much more precise rather than guessing.  Anyone know a good phone app or something?

The sequence ultimately aborted upon failing to meridian flip on the second Pacman sequence, so I didn't get any of the rest of my targets for the night -- NGC 2174, M31 Andromeda Galaxy, Rosette Nebula, or M42 Orion Nebula.

Sooner or later I will get this right!!


  1. Hi Molly,
    Welcome to California. You might be interested in some of the activities of the Peninsula Astronomical Society. Here's a link to the club web page
    James Lockhart