Jupiter and Io's shadow

Finally got a clear shot at Jupiter

along with a bonus Io shadow transit:

animation of the tail end of the Io transit:

Io transiting Jupiter

Imaging details:

edited first image using independently stacked Io

had hoped to image jupiter over christmas break, but nothing but rain and clouds.  pristine skies afterwards, but with seeing so poor stars were flashing like fire engine lights.  managed to get one night of not terrible seeing for this capture.  

a few technical difficulties led to gaps in the capture.  

captured a total of 16 sequences.  processed them all in win jupos then photoshop only to realize that it was too long a time span actually degrading the quality of the image.  

then re-did the whole thing with only 9 images.  

tried bigg sky again. the problem was that the seeing wasn't great so had to smaller stacks (excluding 50%) in this situation bigg sky tends to add noise, so i processed luminance only which muted the colors.  the final image above is mostly registax.  

here are full scale animations with the two techniques.  

note that bigg sky requires sharpening before derotation.  so you wind up with sharpening artifacts that are mitigated by stacking after derotation.  

conversely using wavelets, i undersharpen the individual captures avoiding artifacts, then push the sharpening after derotation/stacking when there is less noise (improved signal to noise ratio).  

Bigg Sky

registax

raw stretched stack after derotation

Bigg Sky

registax

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:

falcon over the back bay take II

still working on composition.  my first attempt managed to catch the backlit falcon in the middle of the frame over the back bay, but wasn't well positioned relative to the foreground.  

my second was a night launch, so no backlight rocket plume, only the bright fist stage:

Falcon-9
Newport Back Bay
10/7/2025

Positioning was better over the back bay, but i've not got the reflection right.  looks like i'm going to have to wade out on the slippery rocks and mud.  

full field:

Imaging details:
Newport Back Bay
for this iteration i moved further north to where the bike path goes under Jamboree

10/7/25 
approximately 20:53 - 20:58 Local
nikon D850
Sigma 15mm F/2.8 EX DG fisheye

video capture 30 frames/sec

composite of a video processed in photoshop

simulating one long exposure

the video was output to individual frames which were combined in groups of 500 in lighten mode

if anyone has a better way to stack the video in lighten mode, please let me know

saturn's disappearing rings 11/23/24

Saturn's rings disappear
9/13/25 7:08.3 UTC
11/1/24 6:08.4 UTC
11/23/25 4:01.3 UTC

Saturn's rings are tilted 27 degrees to the axis of the solar system.  During the course of a saturnian year (29.5 earth years) saturn will have two "equinoxes" with the rings perfectly edge on relative to the sun (once every 13-15 years).  As the rings are extremely thin they will seem to disappear at this point.  On May 6, 2025 when saturn was only visible during daylight, the rings were edge on (my capture attempt failed).  the rings were again edge on on November 23, 2025*.  The animation above shows the rings fading as they tilt to edge-on over the past 2 months.

*why were the rings on edge twice?

my guess is that there are actually 2 different "on edge" conditions.

1. perfectly on edge relative to the sun.  on this day the rings will cast no shadow.

2. perfectly on edge relative to the earth.  

this is rarely at the same time as #1.

In this case my assumption is that the rings were on edge in May.  

Then the earth zipped past saturn (saturn in retrograde for you astrology buffs) with saturn "catching up again" in november. 

This explains the prominent ring shadow across the face of saturn as the rings are slightly less than perpendicular to the sun.  

I will say that visually, the rings were faint but still visible.  guessing this is due to the high dynamic range of the mark II eyeballs.  

they were clearly present on longer exposure images.  

Imaging details:

Seeing has been terrible for the most part this season

exemplified on all of these nights

ZWO ASI664MC

baader IR/UV blocking filter

the sunobserver eADC 

celestron 11" Edge HD, no barlow

East Bluff, CA

9/13/25 7:08.3 UTC

7x90 sec

FPS (avg.)=158

Shutter=6.255ms

Gain=431 (71%)

11/01/25 6:08.4 UTC

7x90 sec

FPS (avg.)=145

Shutter=6.829ms

Gain=431 (71%)

11/23/25 4:01.3 UTC

7x90 sec

FPS (avg.)=173

Shutter=5.714ms

Gain=431 (71%)

captured with firecapture

stacked in autostakkert (upsampled 1.5x)

combined in winjupos 

processed in registax and/or biggsky

photoshop

processing was not consistent across nights

so had to work in photoshop 

to match brightness etc for the animation

ghoulish prominence

Some nice prominences from a sunny weekend:

Prominence 
10/12/25
22:08 UTC

anyone see a ghoul dancing on the sun?

or maybe kokopelli (wikipedia)

animation from the day before (worse seeing):

Solar Prominence 
30 minute animation
10/11/2025 
19:37 to 19:57 UTC

Imaging details:

Here's the lunt on a tracking mount:

Lunt 60 PT B1200 single stacked

zwo ASI 290MM

20 second captures

best 75%

animation

10/11/25

unguided solar tracking on celestron CGX

single frame

10/12/25

manual guiding with alt-azm mount

East Bluff, CA

as you can see, the "seeing" wasn't great during the animation with frames seeming to go in and out of focus.  

took a stupid amount of time to process the 59 frame continuous animation.  

should have put a delay between frames.  

the seeing and prominence shape was better the second day, but didn't have the time for an animation

animation

Frames captured=2328

FPS (avg.)=116

Shutter=0.357ms

Gain=351 (58%)

single frame

composite of two captures:

Frames captured=2328

FPS (avg.)=116

Shutter=1.925ms

Gain=351 (58%)

Frames captured=2325

FPS (avg.)=116

Shutter=1.215ms

Gain=351 (58%)

captured in firecapture

stacked in autostakkert

combined/finished in photoshop. 

maybe a little oversharpened on the single frame ;)

falcon over the back bay

trying this wide field composite of the entire falcon path over the back bay

by a stroke of luck, i managed to center the rocket's arc in the wide field frame.  next time i'll position more to the right to catch the arc centered over the water.  

close up shows the 1st stage trail with intermittent bursts below the rocket and a smaller trail of the fairings:

Imaging details:
Newport Back Bay
7/18/25 
approximately 19:55 - 19:59 Local
nikon D850
Sigma 15mm F/2.8 EX DG fisheye

video capture 30 frames/sec

this is and "artistic" composite of a video requiring a lot of work on photoshop

simulating one long exposure

the video was output to individual frames which were combined in groups of 500 in lighten mode

next came separate processing for the sky and foreground:

sky combined in lighten mode after airplane streaks removed

foreground combined in darken mode to remove car trails.

then final lightening of the sky and rocket trail with curves.  

if anyone has a better way to stack the video in lighten mode, please let me know

Titan transiting Saturn 9/20/25

Saturn's iconic rings are edge-on this year--almost invisible--but this gives an opportunity to appreciate rare shadow transits as the moons (in the plane of the rings) move directly across the face of the planet.  

titan and shadow crossing saturn
9/20/25 06:44 UTC

edge-on rings also allow better appreciation of the subtle bands on the face of the planet (color enhanced).  

Here's and animation of the transit (starting in progress) over 3 hours:

titan and shadow crossing saturn
3 hour animation
9/20/25 05:53 - 08:54 UTC

If you look closely at the animation you can see a few other faint moons dancing around the planet:

titan and shadow crossing saturn
9/20/25 06:44 UTC

Imaging details:
ZWO ASI664MC
baader IR/UV blocking filter
the sunobserver eADC 
celestron 11" Edge HD, no barlow
East Bluff, CA

9/20/25 05:53 - 08:54 UTC
34 x 90 second captures for the animation

20 x 90 second for the still frame
Shutter=~4.02ms
Histogram=~43%
gain 431
~244 fps

captured with firecapture
stacked in autostakkert (upsampled 1.5x)
combined in winjupos 
processed in registax and photoshop
animations are individual captures at 1x

processing notes
caught the transit in process.  
the seeing was not great, though improved
rings were flapping like a bird's wings.
so i'm quite happy with the final processing
at first i thought the "double black dot" was due to seeing errors, 
then realized the lower was titan and the higher, darker it's shadow
the single frame is highly processed with separate processing of the core planet, 
fringe and rings.  
i tried biggsky on Saturn it really didn't like the 1.5 upsampled version
here it is compared to registax on 1x sampling.  
seemed better than registax on the disk, but didn't handle the lower signal rings well.  

probably could have pushed the sharpening in registax, but abandoned this and went with 1.5x upsample.  

registax:

BiggSky:

final registax 1.5x upsampled,

reduced to 1x: