Ad Astra Observatory

It’s been a few nights of unguided astronomy, as I get my feet under me with new gear. The ASI294 continues to make life easy, as it just plugged in where the DSLR lived (it comes with exactly 55mm of extension, natch).

I also installed a Starlight Xpress filter wheel with Baader Ha/OIII/SII filters.

…

that was pretty easy. It plugged in, ASCOM picked it up, SGP picked it up, even has little icons for the filters 🙂

The mount doesn’t like to be left on for long periods of time (there’s a daily 4-min clock error :thinking_face: 😉 ), so after I rebooted everything, I got enough running so that I could manually focus (with a Newt, this process is really kind of fun), and there are things still not quite working after the INDI experiment (plate solving works, but the plate solver can’t move the mount? :shrug: ), but enough to fire off some unguided shots of a favorite (bright!) target. I would have done the whole filter wheel thing at this point, but…

I needed to focus for each filter. Narrowband filters chop a lot of incoming light, and they each have a unique focus point. These are pretty stable (+/- temperature variations) offsets from the unfiltered view, but I had to figure out the offsets 🙂

So, I needed a star that was bright enough to throw diffraction spikes, but dim enough that I could eventually focus with it. This turned out to be a silly idea, but I could the the diffraction spikes anyway, so yay for mag 2 stars 🙂

Next time, I will just focus on Vega. Because Vega :swoon:

For Lum (unfiltered), I used 1s for “frame & focus”, and (later) 2s for autofocus. These were sufficiently bright to throw sharp enough spikes that I could first coarse (100 steps) and then fine (20 steps) focus using the UI, to really get close.

For Ha/OIII/SII, I had to use 8s for “Frame & Focus”, and found the filters to all be over 100 steps away from Lum. I stored the values, and when autofocus failed in that part of the sky, I found an area with no bright stars (defined as “not attached to constellation lines on the chart, but plenty of little dots in the FOV”… science. ), and autofocus went off without a hitch. I stored the *new* values, offsets, …

and then I could suddenly click “Set filter to Ha!” (emphasis mine) and “Focuser, Goto mumble mumble value!” (this one was a copy-paste), and…

Jupiter needed 1/8s exposures through the dim filter, so 8fps would be ~500 frames/min, maybe I can play with the gain settings… :thinking_face:

One more look at M27, because that’s how I do.