Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, May 8, 2022

eta aquarid?

i've recently had bad luck hunting bright meteors under my light polluted skies. Here's my latest effort during the eta aquarid meteor shower.
star trails 5/6-7/22

didn't catch much in the way of meteors, but distortion and chromatic aberration at the edge of the fisheye lens made cool oval star trails and subtle color fringing around polaris:
star trails around the north star, polaris (short arc)

here's a meteor candidate:
Meteor? 5/7/22 ~01:34 PDT
(north upper left)
pretty sure it's not a plane--i'm expert at identifying those, living near an airport.

heavens-above.com (link requires login)  lists one potential satellite.  it's about the right place, direction and time:
Cosmos 1980 rocket pass 5/7/22
Meteor or Cosmos 1980 rocket pass?


but stretching the chart out, aligning on the stars, and allowing for fisheye lens distortion in the image...
the streak in the sky appears to be in cygnus while the satellite passes in cepheus on the chart:
Meteor or Cosmos 1980 rocket pass?

the direction is also about right for an eta aquarid.
so cosmos rocket or eta aquarid?
i'm thinking meteor...
or is it something else?
 
imaging details:
5/6/22 10:46 PM - 5/7/22 2:54 AM (battery died), Eastbluff, CA
poor transparency
nikon D850
Sigma 15mm F/5 EX DG fisheye
30 sec, iso 200





Saturday, April 30, 2022

sunspots (AR 2991, 2993--2997, 2999?) 4/23/22 22:07 UTC

a nice set of sunspots were on display the weekend of 4/23/22.  Here's an animation comparing two views: a traditional "broad band" view showing the spots visible with neutral filter, and a view with a hydrogen alpha (Ha) filter showing ionized hydrogen plasma in dancing magnetic fields above the visual surface.  

Sun WL vs Ha 2/23/22 22:07 UTC

while i generally find the Ha view more interesting, it tends to mask the detail of the sunspots as well as the subtle "granules" on the surface of the sun.  

the visual surface of the sun is called the photosphere, while the Ha/plasma layer is called the chromosphere as hydrogen plasma emits mostly red light.  

Here's a composite Ha view combining a surface image with a much brighter image showing the prominences projecting off the disk edge:

Sun Ha Composite 2/23/22

Here's a small animation of one of the prominences over 4 minutes:

Prominence 4/23/22 22:43-22:47 UTC

another of surface filaments between the sunspots no flares :(

Prominence 4/23/22 22:29-22:37 UTC

next day i pulled out a big scope for higher resolution views of the spots, but the seeing wouldn't really support the magnification

Sun broad band 4/24/22 22:18 UTC
a 2x barlow added no detail :(

Sun broad band 4/24/22 22:25 UTC

Imaging details:

the "broad band" images were actually taken with a Lunt 60 Ha scope with the pressure tuner "off band". this is basically the equivalent of a red continuum filter which, to my eye, passes as "white light".
this conveniently allows "white light" and Ha images through the same imaging train with only a minor adjustment.

  
4/23/22
Ha Lunt 60 PT 
sky-watcher star adventurer mount

full disk
zwo ASI 174MM 
Ha disk
FPS (avg.)=172
Shutter=0.458ms
Gain=190 (47%)
Histogramm=75%

Ha prominences
FPS (avg.)=114
Shutter=4.575ms
Gain=190 (47%)
Histogramm=100%

Ha tuned off band
FPS (avg.)=121
Shutter=0.131ms
Gain=190 (47%)
Histogramm=72%

close up animations
ZWO ASI 290MM 

disk face
FPS (avg.)=71
Shutter=0.468ms
Gain=190 (31%)
Histogramm=78%

prominence
FPS (avg.)=253
Shutter=3.946ms
Gain=190 (31%)
Histogramm=100%

4/24/22
white light images 2/24
celestron 11" Edge HD
ASA mount
ZWO ASI 290MM 

"wider" close up
IR pass 685 filter (sharper than green due to poor seeing)
FPS (avg.)=21
Shutter=0.091ms
Gain=256 (42%)

close up with 2x powermate
ZWO green filter 
FPS (avg.)=38
Shutter=1.847ms
Gain=256 (42%)

processing:
autostakkert
best 20 frames of 20 sec captures
registax, photoshop

East Bluff, CA
4/23-24/22 



Saturday, March 19, 2022

Starry Stormy Night

I don't usually post others' work, but I sort of collaborated:

StormyStarry Night

Notice anything unusual about the sky?

The sky is not filled with van Gogh's stars, but rather swirling storm clouds on jupiter's north pole captured by the juno mission.  The foreground is my daughter's rendition of van Gogh's Starry Night.  After seeing this awesome flyby of jupiter captured by the Juno space craft, my brother commented that the clouds were reminiscent of Starry Night.  So I took a picture of my daughter's painting, a screen shot of the NASA flyby and combined the two in photoshop.  

Here's her original a la van Gogh:

Starry Night by Alice circa 8th grade


and here's the flyby paying homage to kubric (suggest full screen view):

Juno Flyby of Ganymede and Jupiter
Video Credit: Images: NASA, JPL-Caltech, SWRI, MSSS;
Animation: Koji Kuramura, Gerald Eichstädt, Mike Stetson; Music: Vangelis

https://www.nasa.gov/multimedia/guidelines/index.html

more than you wanted to know about 2001 a space odyssey

Saturday, March 12, 2022

Ice Giants and Moons

Here's a capture of Uranus equatorial north (earth's) up:

Uranus
11/29/21 06:50 UTC

Uranus' north pole is rotated to the left 90 degrees relative to the orientation of the rest of the planets in the solar system. a cloud on the north pole makes the left side brighter.  

Here's a wider view using a much longer exposure showing...

the moons of Uranus
Miranda is above, but lost in the glare as it's too close
11/29/21 06:36 UTC


Here's Neptune:

Neptune 11/29/21 4:04 UTC

and a brighter view showing Triton:

Neptune and Triton 11/29/21 4:04 UTC

The magnetic fields of the ice giants uranus and neptune are unusual in that, they are highly skewed/off center from the axis of rotation.  a recent study suggest this is due to super ionic ice (which is just fun to say).  

Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
celestron 11" Edge HD, no barlow
East Bluff, CA
11/29/21 04:04-06:36 UTC
120 second captures
gain 456, exposure ~5-12 ms, 30% histogram, ~60-200 fps
3x upsample (drizzle)


Tuesday, March 1, 2022

animated jupiter

seeing was not great for me this past apparition of jupiter.  here's an animation at low power:

Jupiter 10/4/21 03:34-03:47-UTC

Here's a combination of all of the frames derotated combined.  this gives a smoother image, but blurs the moon and causes edge effects at the extremes:

Jupiter 10/4/21 03:34-03:47-UTC
derotated to each time point

Lastly here's a wider composite image showing the moons:

Jupiter 10/4/21 03:24 UTC



Imaging details:
camera ZWO ASI 290MC with IR block
celestron 11" Edge HD, no barlow
East Bluff, CA
10/4/21 03:24-03:47 UTC
90 second captures
gain 351, exposure ~0.567 ms, 30% histogram, ~200 fps


Sunday, February 6, 2022

spiked sunspots

 unusual spiked sun spots saturday morning ;)

spiked sunspots 2/5/2022 15:55 UTC


according to google they are spiked seed capsules from the gum tree.  if you look closely, there are a few real sun spots, also a prominence at the bottom edge blocked by branches.  here's the prominence a few minutes later:

solar prominence 2/5/22 16:00 UTC
the over exposed central portion has been digitally occluded.  unfortunately shorter exposures to capture detail on the face did not come out well. 

spoiler--annotated true sun spots and prom (click for full size):


Image details:
Ha Lunt 60 PT double stacked
zwo ASI 174MM
manual tracking on alt-azm mount
spiky spots are single frame captures
prominence: 
20 sec capture
FPS (avg.)~48
Shutter~2.283 ms
Gain=234 
East Bluff, CA
2/5/22 15:54-16:00 UTC

Sunday, January 2, 2022

lunar lines: Rima Ariadaeus

a long straight trough on the moon is called a rille (german for groove). just to confuse, "rima" the latin term for crack or fissure  is used when naming these objects.  

Rima Ariadaeus is thought to have been formed when a section of the Moon's crust sank down between two parallel fault lines (click image for wider view):

Rima Ariadaeus
9/13/2021 03:02 UTC

Objects on the terminator (day/night line on the moon) are contrast enhanced by shadows from low angled light--a bit too much in this image as the bottom portion of the line is lost in shadow.  


next up is the crater posodinius:
Posodinius
9/13/2021 02:59 UTC

the secondary rim (top) is apparently not another crater, rather the floor of the crater is fractured and tilted, creating a 1 km drop. also, you'll notice a faint rille crossing from center to upper right.  the crater was not near the terminator during this capture, so the contrast is poor. might revisit while closer to the terminator to capture the rille.


references:
https://en.wikipedia.org/wiki/Rima_Ariadaeu03
http://lroc.sese.asu.edu/posts/796

Image details:
camera ZWO ASI 290MM 
filters: ZWO IR pass 850 
(seeing was mediocre with the 850 filter clearly sharper than a Baader IR pass "685")
celestron 11" Edge HD, no barlow
East Bluff, CA
9/13/21 02:59-03:02 UTC
moon waxing crescent 6.6 day old
FPS (avg.)=73
Shutter=12ms
Gain=251 (41%)