astrophotography by bill w

Monday, October 27, 2025

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 ;)

Thursday, October 2, 2025

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

Sunday, September 28, 2025

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:

Sunday, September 7, 2025

sunny day 6/28/25, bigg sky

perhaps the best combination of surface filaments, sunspots and prominences i've seen this year

Sun 2025-06-28 19:12 UTC, 19:20 UTC
Ha composite (difference)
overexposed version for outer filaments
combined with negative of the central detail

Sun 2025-06-28 19:12 UTC, 19:20 UTC
Ha composite to include faint outer prominences

Sun 2025-06-28 19:12 UTC
Ha color version

Sun 2025-06-28
Ha vs continuum (off band)
conventional sunspots vs plasma filaments and prominences

Image details:

I tried BiggSky blind deconvolution on the images

I have to say it was amazing on the full disk

one click and it was as good or better than tons of fiddling with wavelets in registax

unfortunately blind deconvolution failed miserably on the higher exposure capture for the outer prominences--it can't handle clipping well.

the file management is still a bit clunky, but it's still in development.

looking forward to trying it out on planetary images.

Lunt 60 PT B1200 double stacked
manual guiding with alt-azm mount
zwo ASI 174MM

20 second captures

best 75%

2025-06-28

East Bluff, CA

full disk single stacked bright

19:12.9 UTC

Frames captured=2609

FPS (avg.)=130

Shutter=0.236ms

Gain=370 (92%)

full disk single stacked off band

19:16.3 UTC

Frames captured=2611

FPS (avg.)=130

Shutter=0.032ms

Gain=286 (71%)

full disk double stacked

19:20.9 UTC

Frames captured=2132

FPS (avg.)=107

Shutter=0.173ms

Gain=378 (94%)

captured in firecapture

stacked in autostakkert

sharpened in BiggSky or registax

combined/finished in photoshop.

Saturday, June 21, 2025

neighborhood falcon

the neighborhood turned out for a twilight falcon launch (click on the arrow twice to start the video--the audio is priceless):

first stage shut off:

second stage cruising:

the two small trailing dots are the fairings and the third further back is the first stage
the first stage will land on a barge and the fairings recovered at sea

second stage poofing out:

into the palm trees:

late second stage between the trees and into space:

thanks to Gregg for hosting the neighborhood viewing

(OK maybe not the whole neighborhood, but it was more than just gregg and me so that counts)

In a separate note there's a new cloudy nights t-shirt at astronomics
(cloudy nights is the ultimate web site for amateur astronomy, sponsored by astronomics)
while you may or may not want the iconic grey shirt
the "pitches" on the web site are priceless with the writer channeling J Peterman
so for all you fans of Seinfeld and astronomy (you know who your are)
you must go to the web site and check out the pitches
https://astronomics.com/collections/cloudy-nights-t-shirts/products/cloudy-nights-short-sleeve-t-shirt

imaging details:
6/16/25 8:41-8:44 PM local
Eastbluff, CA

Gregg's front lawn
Samsung galaxy S22 ultra

audio transcript of video:

young child's voice brimming with enthusiasm
"come here quick..."
then softly as if to avoid disturbing the rocket
"...it's right over our house"

in case the pitches go away (from astronomics web site above):

First try...

The Cloudy Nights T-Shirt
(Now with 47% more mystique.)

It was the spring of 1997. Somewhere between the Mojave and a memory, a man named Skip Donnelly sat cross-legged in the back of a rust-orange VW van, peering through a hand-polished 6" Newtonian and waiting for Hale-Bopp to clear the horizon.

He hadn’t slept in three nights. He’d been living off gas station trail mix and a dream. His only companion? A local coyote who seemed to admire his collimation skills.

Skip wore this shirt—or one eerily similar.

It’s Graphite Heather, though he’d just call it “night sky gray.” Softstyle fabric with the kind of 65/35 poly-cotton blend you could sleep in on a moonlit truck bed. It absorbed both dew and regret in equal measure. By morning, the comet came. Bright. Relentless. Eternal.

Skip wept.

He never made it back to Phoenix. Some say he followed the comet, westbound. Others claim he founded a secret astronomy club in Taos that meets only during solar minimum.

We can’t say for sure. But we can say this:

You don’t just wear the Cloudy Nights T-Shirt.
You inherit it.

Second try...

The Cloudy Nights T-Shirt

It was 2:17 a.m. in the high desert of New Mexico.

A lonely astronomer stood beside his Dobsonian like a sentry, hand wrapped around a thermos of coffee that had long since gone cold. Above him, Saturn hovered like a jeweled ringbox in a sea of ink. His fingers trembled—not from the chill, but from awe. And the shirt he wore? It wasn’t just a shirt. It was a declaration.

This is that shirt.

Crafted from a supple blend of 65% polyester and 35% cotton, this Graphite Heather short sleeve garment has seen things—cosmic things. It breathes like a mountain breeze and fits like the warm memory of your first clear sky chart. The logo is discreet, like a secret handshake at a Messier Marathon. The fit is modern, but forgiving. The cut, understated but purposeful.

Available in sizes Small through 4XL for observers of every focal length and flange distance.

You don’t just wear the Cloudy Nights T-Shirt.

You live in it.

And now the one that makes sense to just about everyone.

Cloudy Nights Short Sleeve T-Shirt – Graphite Heather

Show your love for late nights, clear skies, and the community that helps you navigate them both. This official Cloudy Nights t-shirt is printed on a soft, breathable Gildan Softstyle tee in a versatile Graphite Heather color. Whether you’re polar aligning at dusk or just grabbing coffee in town, it’s a comfortable way to rep the world’s largest astronomy forum.

Made from a durable 65/35 polyester-cotton blend, this shirt holds its shape and stays comfortable through long nights and many washes. Lightweight, soft, and just structured enough to keep from looking like a wrinkled star chart.

Available in sizes Small through 4XL—because we support big scopes and big style alike.

Sunday, April 20, 2025

stupid venus tricks--inferior conjunction

Venus inferior conjunction
3/22/25 3:21 PM local
22:21 UTC
1% illuminated
8 degrees 25 minutes from the sun

when you see a really really bright star in the early evening it's probably venus.

and when you see a really bright star in the early morning it's probably...venus.

every 19.5 months (approximately) venus laps earth,
passing between the earth and the sun,
usually just missing the sun,
switching from the evening to the morning star.

this event is called the inferior conjunction of venus (with the sun), the superior conjunction occurring on the far side.

the cool thing about the inferior conjunction is that the crescent is a thin as it can possibly get. if the separation from the sun is small enough, the crescent may even go more than half way around the disk due to atmospheric refraction*

this gives rise to a stupid venus trick:
observe (or photograph) venus in the middle of the day when it is as close to the sun as possible. needless to say, this is DANGEROUS. one glimpse at the sun through a high power telescope is likely to fry your retina, melt optics, or possibly explode telescopes. so one needs to be very careful.

the inferior conjunction before last was hampered by clouds. i caught a quick visual glimpse, but didn't have time for an image.

last time it was hot, sunny and very windy. my goto wasn't working well and a lens cap blew off while i was centering on the sun, causing an unplanned modification of my finder scope, leading me to abandon the attempt:

hole burnt in finder-scope lens cap
it's actually pretty handy

this time i caught it (above), though sadly, i did not catch a more circumferential crescent.

venus transits (crossings directly across the face of the sun) are extremely rare, the last was in 2012, and next will be 2117. and yes venus is retrograde when this occurs for you astrologers.

i was fortunate enough to catch the rare 2012 transit with a brand new solar telescope: