Last weekend's loop de loop 9/1/2024 20:06 UTC

Last weekend (Sept 1st 2024) there was a large coronal mass ejection / flare off of the rim of the sun, followed by post flare loops that lasted for hours.  missed the flare, but caught the loops.  

Solar Prominence 2024 09 01 20:06 UTC

10 minute animation

Solar Prominence 2024 09 01
19:59 - 20:10 UTC

A few minutes on the little guy

Solar Prominence 2024 09 01

Image details:
Eastbluff, CA
2024 09 01
19:59 - 20:10 UTC

M class flare peaked at M5.57 south of AR3811 followed by persistent loops

Ha 
Lunt 60 PT B1200 
manual guiding with alt-azm mount
zwo ASI 290MM
20 second captures
FPS (avg.)=183
Shutter=2.163ms
Gain=351 (58%)
best 25% frames
autostakkert, registax, photoshop
aligned and manually de-rotated in photoshop

here's an autoalign in photoshop without derotation

Solar Prominence 2024 09 01
19:59 - 20:10 UTC

after tedious manual derotation/alignment

Solar Prominence 2024 09 01
19:59 - 20:10 UTC
manual alignment and de-rotation

Loop the loop

Delta Equulei is 60 light years away

 Equuleus (Latin for little horse) is a faint constellation near pegasus (hence the horse theme) rising in the east these nights.  

Constellation Equuleus
"little horse"
horse's head only

Delta Equulei, is the second brightest star in this constellation.  at magnitude 4.47, you'd need dark skies and/or binoculars to see it.

This star is 60 light years away.  

According to Einstein's theory of relativity, the speed of light is the same for all observers.  consider a spaceship moving away from the sun at half the speed of light.  light from the sun speeds by us at the speed of light and then speeds by the ship at the speed of light.  shouldn't it be half the speed of light relative to the ship? 

Speed = distance/time. so the solution is that time slows down on the ship relative to us, keeping the speed of light constant.  

Consider a photon leaving Delta Equulei 60 years ago.  Some of us have experienced 60 years waiting for its arrival tonight.  But the photon, traveling at the speed of light experienced no time at all.  

Something to think about on this day as time flies by.  

imaging details:
nikon D850
poor seeing 
F-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR @ 55 mm F/4.5
20 sec, ISO 400
skywatcher star adventurer tracking mount

Eastbluff, CA

September, 2024

spikes added in processing

apologies for the recurrent theme

Solar maximum, AR 3780

 The sun was littered with sunspots this weekend leading some to claim we've reached the maximum of Solar Cycle 25.  

Sun full disk 8/9/2024 00:05 UTC
Ha Filter "detuned" to continuum.

Sun mosaic 8/9/2024 WL reduced to 33pct

One of these groupings was responsible for another major geomagnetic storm sunday night with aroras visible as far south as texas and arizona (it was cloudy here or my camera would have been out).  

Here's a close up of the largest group, AR 3780 a few days later.  The earth is about the size of the dark circle to the left.  

AR 3780
8/10/2024 23:08 UTC

More shots:

Sun full disk 8/9/2024 00:05 UTC
Ha Filter "detuned" to continuum
colorized

sun continuum v Ha
8/9/2024
00:00.1 UTC
80 pct

Sun full disk Ha exclusion
(central portion inverted)
8/9/2024
 00:00.1 UTC 

Image details:

Ha 

Lunt 60 PT B1200 

manual guiding with alt-azm mount

zwo ASI 174MM

20 second captures

best 20 pct

8/9/2024 00:00.1 to 00:05 UTC

disk:

FPS (avg.)=130

ROI=1936x1216

Shutter=0.032ms

Gain=351 (87%)

Histogram=78%

proms:

FPS (avg.)=106

ROI=1936x1216

Shutter=0.582ms

Gain=351 (87%)

Histogram=100%

detuned surface:

FPS (avg.)=106

ROI=1936x1216

Shutter=0.032ms

Gain=302 (75%)

Histogram=80%

Mosaic

celestron 11" Edge HD, no barlow

ZWO ASI174MM

Baader film, IR/UV block filter, baader solar continuum filter

8/8/2024 23:46-23:49 UTC

20 second captures

best 20 pct

FPS (avg.)=103

Shutter=0.473ms

Gain=380 (95%)

Histogram=89%

close up

celestron 11" Edge HD, no barlow

ZWO ASI290MM

Baader film, 850 nm IR pass filter

8/10/2024 23:08 UTC

ROI=800x800

Shutter=0.056ms

Gain=311 (51%)

Histogramm=91%

East Bluff, CA

generally poor seeing :(

worse on the 8th-9th

4/8/24 solar eclipse epiphenomena

during totality, there is a twilight horizon for 360 degrees.  it's not pitch black, but approximates the darkness an hour after sunset.  you can still see things, though the colors are muted. 

twilight horizon during totality
13:52:11 local, max eclipse
russellville arkansas

fuzzy shadows:

shadows get a bit odd during the advanced partial phases.  note that the shadow of the right edge is sharp while the bottom edge is indistinct 

pin hole projection of partially eclipsed sun
right edge (parallel to crescent) sharp
bottom edge (perpendicular to crescent) fuzzy
1:41 PM, 11 minutes before totality

Inflicting the ritz cracker trick on neighboring families:

pinhole projection of partially eclipsed sun
through ritz cracker onto sky chart
(click image for full size)

i handed out packets of ritz and made friends with my "eclipse neighbors"

pinhole projection through pizza box
courtesy of neighboring family
(click image for full size)

eclipse neighbors
ritz crackers in hand
(click image for full size)

As you can see above, i had a white sheet set up for shadow bands, but did not see any.  though, for the last 30 seconds prior to totality i was tending to the camera, removing the solar filter etc. so may not have noticed.  

Wildlife

The mid-day darkness of an eclipse has been known to confuse local wild life.  while this video clip shortly after totality doesn't show much, you can hear crickets still chirping at darkness, while  young birds begin calling for food as they did at sunrise. (4/8/24 2:06:11 PM local--approximately 2 minutes after totality)

the cows did not moo

At first, i didn't think the cows did much, but on review of my pictures over the course of the day, it appears as though they started over to the left, perhaps by a barn or something, then moved out to the field to graze, later moving into the shade of trees during the midday sun.  during thinning crescent phases as the daylight faded and reddened, they seemed to move back to the left...maybe just random.

moo

i'm definitely not a cloud expert

the nature of cloud formation during a total eclipse gets fairly complex.  not sure i noticed any eclipse specific clouds, other than the thin line going right across the sun during totality :(

but i did notice an unusual difference after totality.  the sun moved across the sky from left to right.  the "pre-eclipse" clouds to the right look like typical poofy things, while the "post-eclipse" clouds to the left have a linear pattern.  This article suggests low level cumulus clouds dissipate during an eclipse due to altered convection, while thin high level clouds persist.

panorama
40 minutes after totality

Imaging details:

4/8/24 

Russellville, AR

35 deg 18.366 min N

93 deg 7.962  min W

solar transit 1:13:38 PM

totality ~1:50-1:54 PM local, alt 61 degrees

first contact 12:30:10 PM local

second contact (totality) 1:50:08 PM local,

third contact (end of totality) 1:54:15 PM local

fourth contact 3:10:50 PM local

samsung galaxy S22 ultra

4/8/24 solar eclipse travelogue, Russellville Arkansas

a thin cloud across the sun during totality didn't really interfere with the visual experience (photos another story).  i could easily see the black disk surrounded by a glowing ring of light, and colored prominences.  that being said, someone about 100 miles north along the track reported clear skies for totality :(

Thin cloud passing right in front of eclipsed sun. 
Russellville, Arkansas 4/8/2024
also note Venus (right) and Jupiter (left)

The first thing i did in planning for the 2024 eclipse was to find the location with the best chance of clear skies...

Bad news.  Based on historical data, the chance for clear skies was less than 50% across the entire US eclipse path, with the chance being best in the south and worse further north.  Furthermore, the weather patterns were such that large swathes of the path would be taken out all at once, so not easy to drive to clear skies.  

after hours combing through this website run by eclipsophile  meteorologist Jay Anderson, i came up with Kerrville Texas as the best location, with Russellville Arkansas as a back up, and Cleveland as a third (a friend from Cleveland talked me out of this one).  I booked refundable flights and rooms for both, making the final decision two days before the eclipse when weather models can be fairly accurate.  At that point the chance of heavy clouds was near 100% for southern texas and very low for arkansas. ironically maine, which a priori had the worst chance of clear skies wound up being the best:

weather satellite view of the eclipse shadow from 
pivotal weather.com

russellville seemed a pretty popular destination for the west coast

many people watched the eclipse from in front of the hotel where they were renting out parking spaces next to a lawn.  playing up to the event, the hotel gave out schwag bags including sun chips, capri sun, star burst, and eclipse gum...i had my own bud lite.  from there, they viewed the eclipse over the holiday inn--a great ad, but not the most scenic.  

after scouting a few locations in the area, i went back to my hotel and spotted a nice green pasture with a few cows right out back (seemed very Arkansas): 

eclipse scouting, holiday inn, Russellville AR

Will the cows moo at the moon covered sun?

more details:

samsung galaxy S22 ultra

detailed interactive eclipse path:

http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2024_GoogleMapFull.html

also links to optimal exposure times

eclipse weather:

https://eclipsophile.com/2024tse/

weather in arkansas typically better slightly north of center line, hence russellville

last minute weather:

pivotal weather

5/15/24 surreal sunset in front of clouds?!

Driving home the other night i caught something odd out of the corner of my eye at sunset:  the horizon was bright orange with the setting sun lighting up a thin cloud.  below that a thick bank of dark clouds went down to the horizon.  in front of that was the grapefruit pink disk of the setting sun.  

WAIT, IN FRONT OF THE CLOUDS?!

I pulled over and snapped these pics with my phone (click for larger size):

captured these images at back bay park overlook, as amazed by the sight as by the fact that joggers and cyclists passed by paying no attention. 

a woman wearing a white baseball cap power-walked by with her eyes down at her phone. i gestured to the horizon and said "have you seen it?"

she looked up at me like i was a lunatic (guilty), looked back down at her phone, and kept walking :(

simple explanation is that the sun is shining through the clouds. 
i have a feeling there's a bit more going on: the top of the grey cloud bank looks just too dark and thick to let the sun through, but lower down, at the level of the sun it seems to lighten a bit. 
i'm thinking the refracted sun is passing through a lighter layer of clouds/fog lower down.

image details:
5/15/24 7:42 pm local
backbay park overlook (easbluff and jamboree), newport beach, ca
samsung galaxy S22 ultra

4/8/24 solar eclipse chromosphere animation (pretty red stuff)

Chromosphere
total solar eclipse (late totality)
4/8/2024 1:53:58 pm local
eastern limb up

The chromosphere is the layer of red hydrogen plasma that sits above the photosphere--the bright surface of the sun that emits the full spectrum.  during a total solar eclipse the photosphere is completely blocked, allowing one to see red arcs of hydrogen plasma jutting off the side of the sun with the naked eye.  Here are a series of images at short exposure, showing the chromosphere, without the extended outer corona of the sun or the brilliant photosphere.  

Fortunately, I previewed Ha images of the sun shortly before the eclipse, so knew to look for the red arc on the lower right (see video) towards the end of totality.  It was spectacular visually, even through light clouds.  

Be sure to click on full size.

Imaging details:
4/8/24 
Russellville, AR

35 deg 18.366 min N

93 deg 7.962  min W

~1:50-1:54 PM local
nikon D850
AF-S NIKKOR 300mm f/4E PF ED VR
f/5.6, iso 100, 1/6400-1/800 sec exposure
skywatcher star adventurer tracking mount
eclipse orchestrator for automated image capture
oriented solar north up now.  

processing notes:

matched the exposures in photoshop camera raw to 1/3200 sec

aligned the frames on the corona manually so the moon is moving across the stationary sun

because it was much harder to do than auto align on the moon, so why not?

shot continuously at 2 second intervals in the beginning and end.  mid eclipse images were spaced further out due to longer exposures, so i used the "tween" function in photoshop to give a smoother transition between frames (adjusting the number of interpolated frames to the elapsed time).