Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

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%)


Thursday, November 11, 2021

Venus in infrared and ultraviolet 9/13/21

Here are several images of venus captured with infrared and ultraviolet filters. UV  light shows cloud structure which cannot be seen in the visible spectrum while IR in this case gives a sharper image, but no cloud detail:

Venus IR 9/13/21

Venus UV 9/13/21

Venus UV (colorized) 9/13/21

Venus IR as red, UV as violet 9/13/21

the seeing was fair to poor.  my intent this day was to image mercury, but i could not locate it during daylight with my overloaded mount.  here are the raw stacks with two different IR pass filters one at 685 nm, the other 850 nm.  the 850 being further into the infrared is generally preferred for mercury or poor seeing conditions, the latter being the case here:

Venus IR (raw stack) 9/13/21


Image details:
camera ZWO ASI 290MM 
filters: Baader IR pass "685", ZWO IR pass 850, Baader U-filter bw 320-380nm
celestron 11" Edge HD, no barlow
East Bluff, CA
9/13/21 00:13-02:17 UTC

685 filter:
FPS (avg.)=212
Shutter=0.101ms
Gain=234 (39%)
850 filter:
FPS (avg.)=20
Shutter=1.351ms
Gain=234 (39%)
UV filter:
FPS (avg.)=201
Shutter=4.952ms
Gain=351 (58%)



Sunday, November 7, 2021

solar stuff

Solar Prominence Ha 
8/15/21 18:20 UTC

 
Solar Prominence Ha 
8/15/21 18:20 UTC
Exclusion

Solar Prominence Ha 
8/15/21 18:32 UTC
smaller prom from the side of the disk (rotated up)

There was a lot of excitement in the solar community this week due to a series of solar outbursts directed at the earth, some massive.  I actually caught the beginning of one visually on 10/28, but did not take pictures.  according to spaceweather.com a cannibal coronal mass ejection (fast moving coronal mass ejection, running into a slow moving one) hit the earth creating auroras visible as far south as 39 N in central california; detectable in cameras as far south as joshua tree. 

it was of course cloudy here so i missed it all as well as the taurid meteor shower and the new moon :(

The images above show a pretty big solar prominence i captured on 8/15/21 and have absolutely nothing to do with the events described ;)


Image details:
Ha Lunt 60 PT double stacked
zwo ASI 290MM
manual tracking on alt-azm mount
20 sec captures
FPS (avg.)~93-178
Shutter~0.331-2.283 ms
Gain=351 (unity)
East Bluff, CA
8/15/21 18:20, 18:32 UTC

Saturday, September 18, 2021

Jupiter got smacked

the astronomy community was abuzz last week when an amateur astronomer in Brazil captured video of a  bright flash as a meteor estimated at 100 m crashed into jupiter.  At least 10 other observers independently observed the event, making it the most observed impact on jupiter to date; the eighth recorded since the first was observed in 1994.  More information can be found in this sky & telescope article

Had the meteor struck earth it would have been equivalent to 34 megatons of TNT (hiroshima was 15 kilotons).  Jupiter's massive gravity is thought to protect earth from many of these collisions.

Despite the fact that observers were not able to find any residual storms (which have been sighted after prior impacts), i decided to check out the impact site with a methane filter.  unfortunately, the Jupiter Central Meridian calculator cited in the article is now defunct and spat out the wrong data--so i completely missed the site (holy homophones).  nevertheless i got some colorful pictures of jupiter:

Jupiter 9/16/21 04:38 UTC.  RGB left, Methane center, Methane as red, GB right

Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader methane 889 nm 8 nm bandwidth
celestron 11" Edge HD, no barlow
East Bluff, CA
90 second captures, 2x binning for methane
gain 351, exposure ~0.6-1.0 ms, 30% histogram, ~280 fps
methane exposure 375 ms, 2 fps

Tuesday, September 14, 2021

a rocket at night: falcon 9 launch 9/13/2021

visually it was a spectacular event, there was something surreal about seeing the long bright orange rocket plume slowly rising up through the trees.  it looked very...well rocket-like.  perhaps we'll be used to it in years to come.  perhaps residents closer to vandenberg are already used to it--tired of it?

 Unfortunately, my images were pretty much a bust, but here are a few salvages, the best from my cell phone:

Falcon 9 from Coastal Peak Park 9/13/2021



image details:
Samsung Galaxy Note 9
f/1.5, 1/4 sec, 4 mm
Nikon D850
Nikon Nikkor AF-S DX Telephoto Zoom 55-300mm f/4.5-5.6G ED VR
f/4.5, 2 sec, iso 5000, 55 mm

much processing in photoshop to correct star trailing due to camera shake as my remote wasn't working.