My objective tonight was to begin imaging the Soul Nebula for HAL’s Winter Imaging Activity (WIA). I knew at the outset that I still had to work through some process issues to get up and running. I almost made it to the capturing some useful data, but not quite.
As for conditions, it was chilly at the outset. Not sure what the temperature was then, but it was 35 degrees when I came in. No issues at all with the dew. There were some high, thin passing clouds that eventually moved out. Seeing was not an issue at fl=540mm. Transparency didn’t seem to be an issue.
For preliminary work earlier in the day, I had re-leveled the mount after taking the Meade down. Since it had been set up for three months, I was not surprised to see that it was noticeably off. Then I put the TV/ASI6200 set up on the G11 and worked out how I would collect Flat, Dark, and Flat Dark frames. The because of the bright mid-day sunshine, light was leaking in somewhere and ruining my Darks. It took a while to solve that. Still not sure whether the leak was from the front of the scope/around the dew shield, for from the back of the scope where there are several connections between scope, field flattener, OAG, filter wheel, and camera. Not sure that I need to solve this, because I do not anticipate collecting darks and flats in the daylight.
I went out at about 1900. It was already very chilly. I worked at the scope for about 45 minutes doing polar alignment. I experienced a transient issue that kept me on this task longer than usual. I brought up the camera and achieved initial focus, slewed to meridian-equator for PHD calibration (slight orthogonality error, but was getting sub arcsecond guiding!), and slewed to the target. I was pretty cold by the time I came in.
Once inside I began work to decide on an exposure duration. That went well and I settled on 360s, which put the left peak of my histogram about 20% from the left edge. I then began working on framing. The target has an elongated shape that needed to be aligned across the center of the long axis of the frame. The problem here is that the nebula is too dim to be seen in a single frame, so I had to rely on matching star patterns to get the orientation correct. I figured out that a 90 degree rotation in either direction would be perfect, so I rotated the camera and went back inside.
I needed test exposures, but NINA had stopped taking images, and guiding stopped. I could see nothing in the software, so I went back outside to check. It turns out that when I rotated the camera, the USB that carries both cameras to the mini computer had gotten unplugged. I took care of that and went back inside.
Getting back to work, I discovered that my guiding error was off the charts. I went outside to check for cable snags, but couldn’t find anything wrong. I worked on this by restarting everything, but the condition persisted for about 30 minutes. I finally realized that the camera rotation made the calibration invalid, so I recalibrated.
While trying to get back to equator-meridian from Stellarium, I saw the scope head straight east toward the meridian and it kept on going. No idea why. I went outside and found the scope up against the pier. I manually moved it to park, shut everything down, and went back inside. It was 2200, and the temperature was 35 degrees. I was uncomfortably cold from my trips outside.
There is nothing in particular that I want to work on tomorrow. Everything worked pretty much as it should until the errant slew toward the end. I imagine that issue, like all of the others that I experienced, was a result of my error. Hopefully I have cleared the backlog of Jim issues that need to be worked out, and perhaps I can get to imaging forthwith on my next outing.