Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

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%)

Monday, December 20, 2021

still more great lunacy: theophilus and friends, ghost crater

also seen in the wider image in the previous post is this trio of craters:

Theophilus, Cyrillus and Catharina craters
 9/13/2021 02:54 UTC 
the age of these craters increases from left to right (north to south):
theophilus (left) has steep sharp terraced walls and a steep triple peaked central mountain.  
cryillus (center) has more rounded walls, with the northern interrupted by theophilus.  the central peak is also rounded and less prominent.  
catharina (right) has low rounded edges with no terracing and multiple craters interrupting/obscuring the rim.  nothing remains of the central peak.  



Lastly, can you find the "ghost crater" in this wider view (click for full size)?

ghost crater daguerre upper left
(straight up from theophilus)
almost entirely covered by lava
 9/13/2021 02:54 UTC 

ghost crater daguerre
almost entirely covered by lava
 9/13/2021 02:54 UTC 


references:
https://en.wikipedia.org/wiki/Theophilus_(crater)
https://en.wikipedia.org/wiki/Cyrillus_(crater)
https://en.wikipedia.org/wiki/Catharina_(crater)
https://en.wikipedia.org/wiki/Daguerre_(crater)


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 02:43-03:02 UTC
moon waxing crescent 6.6 day old
FPS (avg.)=73
Shutter=12ms
Gain=251 (41%)

Sunday, December 19, 2021

more lunacy, rupes altai

here's the feature that helped me identify the crater in the previous post:

rupes altai 9/13/2021 02:54 UTC 

the distinctive curved white line is called rupes altai, a ridge that can be best seen in the lunar morning with the sun shining on it's face (5 days after the new moon), or in the lunar evening with it casting shadows (4 days after the full moon).

nearly 500 km long and 3 to 4 km high, it's the rim of a gigantic impact basin (mare nectaris-smooth area upper left in image below)

it terminates on the right hand side at the crater piccolomini

a wider view (click on image for full size):

rupes altai, lower right 9/13/2021 02:54 UTC 

rupes altai, rim of giant impact basin
mare nectaris



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 02:43-03:02 UTC
moon waxing crescent 6.6 day old
FPS (avg.)=73
Shutter=12ms
Gain=251 (41%)



Friday, November 26, 2021

let the lunacy begin with john of holywood aka sacrobosco

 i know very little about the moon, but once in a while i'll turn my planetary rig to the really bright thing in the night sky.  my usual approach is to take pictures of cool looking stuff, then learn what i've captured later.

Craters within craters caught my eye here:

sacrabosco 9/13/2021 02:43 UTC

The age of a lunar object is often estimated by how many craters there are.  so craters filled with other craters are probably old structures.  the soft cratered rim also looks old.  It took me quite a while to identify the central crater:

"Sacrobosco is an irregular lunar impact crater that is...a readily identified feature due to the three circular craters that lie on its floor." (err not so readily by me) wikipedia

Named after John of Holywood, Johannes Sacrobuschus Sacrobosco - British astronomer, mathematician (c. 1200-1256). ref

here's a wider view, click on the image for a full screen moon walk:

sacrabosco 9/13/2021 02:43 UTC

lunar surface detail is best photographed near the terminator (dividing line between light and dark) as the enhanced contrast brings out detail.  the problem with that is that most lunar atlases have a bright full moon view with a black shadow overlay, but no actual shadows on the surface.  here's the atlas view of the central crater:  


note that the 3 internal craters are easily visible, but the larger and much older crater is difficult to see without the sun's contrast bringing out its soft edges.  i was only able to identify it by finding the bright ridge at the top of the larger image and working backwards...

UPDATE:
i just found the needed site:
nasa's scientific visualization studio
gives relatively high resolution images with appropriate shading based on date as well as some labels
https://svs.gsfc.nasa.gov/4874
(wish i'd found it earlier)

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 02:43-03:02 UTC
FPS (avg.)=73
Shutter=12ms
Gain=251 (41%)