ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod

I only had a few minutes between the clouds, so no heavy post-processing this time, given that I don’t have the usual 10×3 minutes, which significantly reduces the … noise, a pixel size “something” I guess, present  either in the instrument or really on the Sun.

The gear: ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod

Same happenned for 2012-12-15, only a few minutes. We can see the beautiful spotted region rotating into view

Finally, the clouds broke over the ersatz-obsi, and the Sun is showing some awesome activity. The image was taken, as usual, through the Calcium filter, which I found yields the best images, hydrogen alpha aside, of the surface of the Sun, running circles around the solar continuum, as long as a full disk image is the goal.

ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod, with the automated filterwheel.

Using a setup I no longer have, an Atik camera, I made a mosaic of the Sun with the N150/750 tube, through the Baader K-Line Filter 1.25″ (double stacked) filter. I processed it back then, and reprocessed it now. It shows the difference.

Calcium K (2015)

Calcium K 2015, reprocessed in 2021

ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod

ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod

ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod

ASI 178MM (cooled), Baader K-Line Filter 1.25″ (double stacked), TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod,18x3minutes,  the best  300  frames from each sub, stacked.

While I have a few theories about why the UV, through glass, looks the way it looks, I’ll leave the theory out.

ASI 178MM (cooled), %filter%, TS-Optics 76/342 TS76EDPH, mountpusher, EQ3-mod with either ND5 or ND3.8, as the band pass filter asks for it.

Also, I updated the filterwheel’s firmware. If you are wondering why it’s not on github, wonder about microsoft a bit.

One can see how limb darkening is truly stronger in the blue end of the spectrum, and that for most intents and puproses, the Calcium K yields the second best amount of detail, after the… hydrogen alpha. The solar continuum is, comparatively, useless for full disk images.