sun 12/7/2025

the series of sun spots (active regions AR 4296, 4294, 4298) were indeed active, blasting ions at the earth in early December.  i happened to catch them during a day with good seeing (i can't usually discern the "granules" in the white regions so well):  

AR 4296, 4294, 4298
12/7/2025
21:51.6 UTC

Granules are convection cells in the sun's photosphere.  "The rising part of each granule is located in the center, where the plasma is hotter. The outer edges of the granules are darker due to cooler descending plasma" (wikipedia). 

I also captured a series of full disk images in Ha:

Sun Ha Surface
2025-12-07 20:58.3 UTC

Sun Faint Ha prominences
Digital occultation of disk
2025-12-07 2058.9 UTC

Sun 2025-12-07 
Ha composite

Ha composite
difference

Solar surface
Ha vs off band

Sun Ha vs white light

Image details:

close up

Celestron 11" Edge HD

Baader solar film

green filter

unguided solar tracking on celestron CGX

full disk
Lunt 60 PT B1200 single stacked

zwo ASI 174MM
2025-12-07

all 20 second captures full frame
East Bluff, CA

better than usual seeing

close up:

Frames captured=2064

FPS (avg.)=103

Shutter=0.082ms

Gain=325 (81%)

full disk surface Ha:

Frames captured=2610

FPS (avg.)=130

Shutter=0.073ms

Gain=280 (70%)

full disk prominences:

Frames captured=2606

FPS (avg.)=130

Shutter=1.958ms

Gain=280 (70%)

full disk off band:

Frames captured=2609

FPS (avg.)=130

Shutter=0.032ms

Gain=302 (75%)

captured in firecapture
stacked in autostakkert
sharpened in BiggSky or registax
combined/finished in photoshop.  

Processing notes:

for the close up

a zwo green filter gave slightly better contrast compared to luminance (UV/IR block).

i also captured 30 minutes of the full disk in Ha for an animation...there was minimal activity over the course of the animation :(

BiggSky wasn't as good as registax for full disk or proms, but looked better than registax to me for the close up green light image (though slightly over-sharpened). 

raw big sky:

registax: