The Starry Night, 232

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October's Bright Blue Weather

10/17/2022. It's relatively clear and dark tonight with plenty of time between sunset and moonrise. I have three projects:

  • A plausibility check of O-iii on planetary nebula Abell 39 which will be a subject for another year. I saw a killer photo of it on Astrobin (with a 24" CDK, but still). Tonight I just missed it -- I wrote the RA down right, but missed anyway. See below!]

  • R and B data of LBN332. I didn't start guiding until fairly late in the run. The 180s data looks surprisingly good anyway.

  • And another try for a significant luminance harvest from M33. I'd like to get that data pile up to 10-12 hours, and if the weather holds, I can get over halfway there tonight. It's very windy, even down under the pines. I've removed the dew shield / sail for tonight. (ETA: There's spindrift coming down from the mountains! Luminance data looks good. Now up to 8h18m.)


10/18/2022. I took another cut at Abell 39. I grabbed very short R and B frames, and then exposed O-iii until the field hit the treetops. Mostly this was an audition; if it shows up at all in a handful of 3 minute, unity gain, O-iii frames, then I'll have a good chance of doing good things with it when it comes around next year. Here's 5x180s of O-iii data, stacked (and pushed pretty hard):

abell 39

Abell 39, 5x180s, O-iii, unity gain
AT10RC at F4.8, ASI1600MM


It was supposed to be centered, but at least this time it's in the frame. So how did I miss it so far? Do this: launch Guide using Epoch 1950 coordinates (I was looking up some stuff from old sources many months ago) and copy the position of your target off the screen. Give that to GTOCP3 computer which uses epoch of date for its stored position (I'd recalibrated on Vega a few minutes earlier, and when I did that, the computer precessed its stored position for Vega to the epoch of date; when I supplied coordinates in B1950... well what was it supposted to do except go there? Set Guide to us current coordinates and all will be fine.

After Abell 39, I started an earnest try for the Soap Bubble. And later, overnight, I'll see if I can get M33 over the 12-hour mark in luminance [11h 54m!]. I don't think I have enough R and B data yet to do much with it, and I know I don't have nearly enough H-a to spice up the star-forming regions. All in good time. In the meantime, black and white is elegant.


10/19/2022. The Soap Bubble is tough. I had good luck with the 92mm refractor and the Canon R6, but somehow the AT10 and a dedicated astrocamera find that it's a challenging target. (Psst: it's because I thought it was mostly an O-iii subject, but it isn't.)

I tried Abell 39 again first thing tonight. Setting Guide to epoch of date worked fine, but the sky was less cooperative, and I got nothing worth saving. Next, the Soap Bubble and I are trying again: 300s high gain H-a start to finish. See next page.

The only O-iii in the scene is, apparently, a thin boundary around part or all of a hydrogen bubble. When that field got low, I shot M52. I didn't have time for a good job the real Bubble Nebula, but I didn't want to to just let the 'scope sit while M33 crossed the meridian and into my open sky.

Finally, I set up 12 more luminance frames of M33 (just because), and then a night's worth of R and B. H-a can wait.

The weather remains clear; I'm still adding data. Read on. Read on.


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My deep-sky photos are made with a variety of sensors and optics. Deepest images come now from a ZWO ASI1600MM Cooled Pro CMOS camera, an ASIair (model 1) and sometimes one of several laptops. A good many images come from an unmodded Canon 6D but a lot more will be coming from an R6. Video and video extracts begin in a Canon EOS M, usually running in crop mode via Magic Lantern firmware (but the 6D and especially the R6 will probably see more use). Telescopes include an AT10RC, an Orion 10" F4 Newtonian, and a pair of apochromats: a TMB92SS and a AT65EDQ. A very early Astro-Physics 5" F6 gets some use, too. So do lots of camera lenses on both the ASI1600 and on the Canons. A solar Frankenscope made using a 90mm F10 Orion achromat and the etalon, relay optics, and focuser from a Lunt 60 feeding a small ZWO camera will see more action as the Sun comes back to life (Autostakkart!3 is my current fav for image stacking). Mounts include an iOpton SkyTracker (original model), a bargain LXD-55, a Losmandy G11 (492 Digital Drive), and an Astro-Physics Mach1. PixInsight does most of the heavy lifting; Photoshop polishes. Some of the toys are more or less permanently based in New Mexico. I desperately hope to get back soon.







                   © 2022, David Cortner