Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, February 28, 2021

mars wrap up

Mars is all over the recent news with a fleet of space craft arriving: 

-NASA's perseverance pulled off a crazy landing with a supersonic parachute (which just sounds cool), followed by a heat shield, then rockets, and finally a sky crane lowering the lander into the dust with the rocket hovering above. NASA video.  

-the UAE's Al'Amal (hope) is orbiting the planet and filming. 

-China's Tianwen-1 is orbiting, preparing to send down a lander.  

Perseverance is loaded with easter eggs including a binary message encoded in the parachute: "Dare Mighty Things", the motto of NASA’s Jet Propulsion Laboratory (JPL) and the coordinates of the JPL visitor's center: 34°11'58.0"N 118°10'31.0"W. 

More easter eggs here

You can even follow the perseverance twitter account:

"Hobbies: Photography, collecting rocks, off-roading" 😄

so here's an excuse to process the rest of my mars opposition images.  the following sequence shows the south polar cap slowly melting in the martian summer (though some of the change is due to rotation).  

Mars 2020
Click for full size

Here's a final shot at shorter focal length from the evening of the great conjunction:
Mars 12/20/2020
wave goodbye


long winded technical imaging stuff: 
the right hand image above was captured with a one shot color (OSC) camera.  an 850 nm IR filter was used to capture IR frames.  how can an IR filter work with a OSC camera?  all of the color filters pass IR (this is why you need an IR blocking filter for many OSC cameras).  so theoretically a relatively long IR filter will pass IR to all color pixels giving a mono IR image.  

unfortunately i didn't realize i needed to uncheck the color balance during acquisition, so the pass-through wasn't uniform by color: it yielded the typical checker board appearance one sees with an undebayered color image.  color conversion gave a blue tinted image.  each of the "color" images were identical, so a simple color balance gave a mono image.  perhaps it was the conditions or the filter, but the debayered IR image offered no improvement in resolution compared to the red filter.  which is not my experience with a mono camera, though i've not tested the 850 mono yet.  
***will have to try again with the white balance adjusted next season

from a practical stand point IR/OSC images probably don't add much unless there's a major dust storm interfering with surface visibility as in the 2018 opposition.  

in a prior post i noted that while using IR as luminance generally improves the contrast/sharpness of the blue surface detail, it loses subtle cloud detail.  i note an interesting corollary to that with this image: using IR in place of the red channel will enhance clouds as they appear bluish compared to the background:
Mars 11/15/2020 06:17 UTC
IR-G-B

Image details:
celestron 11" Edge HD
ZWO ASI 290MM
ZWO RGB filters, Baader IR pass "685" nm
30% histogram
firecapture, autostakkert, winjupos, maxim, photoshop

9/29/20 07:35 UTC
2x120 second captures each filter, 400 FPS
gain 351, exposure ~.2 ms, 
tried a methane filter for fun which was like a bad IR filter :(

10/11/2020 8:27 UTC
2x120 second captures each filter, 400 FPS
gain 351, exposure ~.2 ms, 

10/14/2020  07:48-08:09 UTC
very good seeing
*televue 2x barlow*
2x120 second captures each filter, 200 FPS
gain 351, exposure ~1 ms, 
elevation ~60 degrees

11/15/2020 06:17 UTC
ZWO ASI 290MC
ZWO 850 nm IR pass filter
6x120 second captures RGB, 400 FPS
gain 351, exposure ~.2 ms, 

Eastbluff
Southern California...

Thursday, December 31, 2020

Fireball 7964-2020 Heralds the Great Conjunction

Here are a my conjunction images.  

12/20/2020 note great red spot showing on Jupiter

Great Conjunction 12/21/2020
day of closest approach

You'll note that Jupiter (which has four bright moons) appears to have 5 moons in the first image, but only 3 on the day of closest approach!?  In the first, a background star is in disguise as a moon, while in the second, Ganymede is attempting to hide from view as it crosses the surface of the planet (see annotated versions below).  

12/20/2020


12/21/2020

The event was heralded by a fireball (bright meteor) seen by thousands.  It ocurred at 5:11 PM pacific, less than 30 minutes after sunset with the southern sky still bright blue, making this the brightest I've ever seen.  It looked like a firework with sparkles.  Scott Young from our astronomy club put it better: "I was looking directly at the planets and the fire ball came from the north and traveled south.  It burned up just after falling below the planets.  Long streak with lots of fragments and a burst just before the burnout.  I'm sure it was an Ursid".  About 10 minutes after seeing it, I made a quick sketch as it was hard for me to describe the direction:

you can see why i take pictures :)

There were documented sightings from Santa Barbara to San Diego:

very tall astronomers

It has been labled as event 7964-2020 by the American Meteor Society.  More info at links below:

American Meteor Society log of event 7964-2020 -includes video
december meteor forcast
ursid meteor shower

Image Details:

Imaging rig including telescope for telescope for telescope. 
hedge obstructs low southern horizon :(

The conjunction images are composites of multiple exposures: short tight crops at high frame rates for each planet.  a combined image of the two planets with saturn much more faint relative to jupiter than in the composite.  a longer exposure for the jovian moons, still longer for titan, and longest with a stretch for the faint moons of saturn.  

Takahashi FS 102 at 820 mm, ZWO ADC, Baader IR/UV block filter, ZWO ASI 290 MC
captures ranged from 0.34 ms exposures at 400 fps to 100 ms at 8 fps
Eastbluff, CA 12/20/20 and 12/21/20



Friday, December 25, 2020

Gas giants 2020 including disturbance in jupiter's NEZ with methane filter

 Taking a break from conjunction processing to post these larger images of the gas giants:

Saturn 9-25-2020 03:49 UTC RGB

Saturn 9-25-2020 03:49 UTC RGB


Jupiter 9-25-20 03:23 UTC
note white dot in the upper band, a disturbance in the northern equatorial zone noted this past summer

Jupiter 9-25-20 03:23 UTC Methane filter
enhancing disturbance in upper atmosphere of NEZ
(white dot upper half)

Methane RGB
Jupiter 9-25-20 03:23 UTC Methane filter as red, green, blue
enhancing disturbance in upper atmosphere of NEZ

Previous post with more information on jupter images with a methane filter:

image details:
celestron 11" Edge HD
ZWO ASI 290MM
zwo RGB filters
Baader methane 889 nm 8 nm bandwidth
sharpened in registax
combined in winjupos
Jupiter: 9-25-20 03:23 UTC
Saturn 9-25-2020 03:49 UTC
no sign of the hex :(
fair seeing
Eastbluff
Southern California

Sunday, December 13, 2020

winter is coming...a geminid

Here a few wide fields and my attempt at imaging the classic winter meteor shower, the geminids (night before peak which was clouded out).  

Orion Rising...winter is coming.  when you see orion rising in the early evening, winter is on the way.  note Betelguese (red "shoulder" upper left) no longer faded:

Orion rising 12/12/20
have to do something about that fence :(

here are a few hours worth of star trails.  only one sad meteor, can you find it?

Star trails 12/12/20

close up:

a geminid

Localized:

a geminid 12/12/20



image details:
12/12/20, eastbluff, CA
Bortle white skies
nikon D850
Sigma 15mm F/5 EX DG fisheye
30 sec, iso 200

Saturday, December 5, 2020

Uranus 12/1/2020 07:15 UTC

Uranus 12/1/2020 07:15 UTC IR(685)-RGB
Planetary north up


Image details:
camera ZWO ASI 290MM
ZWO RGB, Baader IR pass 685 nm filters
celestron 11" Edge HD
East Bluff, CA
12/1/20 07:15 UTC
fair seeing 3/5 on clear dark sky clock
120 second captures, 2x each color filter, 3 sets of 3 for IR 685
gain 456 , exposure ~12 ms red, 5 ms green, 8 ms blue, 31 ms IR 685 30% histogram
upsampled x2 in autostakkert, derotated in winjupos.
initial wide field capture with moons key to alignment in winjupos.  
oriented planetary north up.  
color balance-eyeballed ;)
tried a methane filter...not enough signal

RGB only:
Uranus 12/1/2020 07:15 UTC RGB

Saturday, November 28, 2020

Random moon pics

Here are a few random pics of the moon. i'm not much of a lunatic, can't really name craters etc.  just grabbed a few pics when it caught my eye while setting up image sessions.  

lunar halo 11/29/20

lunar halo close up composite 11/29/20

a nice crescent captured with my deep sky camera on a 4" refractor while imaging hickson 68.  single shot, no stacking:

Moon 4-26-2020-03:30-UTC

Next a moon walk on the terminator during a waxing gibbous with a high magnification planetary set up:

Moon 9/25/2020 03:05 UTC (click for full size)




mosaic, 9/25/2020 03:05 UTC (click for full size moon walk)


image details:
lunar halo
nikon D850
wide field: Sigma 15mm F2.8 EX DG fisheye
close up: AF-S DX NIKKOR 16-85mm F3.5-5.6G ED VR 16 mm
11/29/20 east bluff, CA

crescent
FS102 OLV @ 627.8 mm,
Starlight Xpress Trius 694, 1.49"/Pixel
ASA DDM60
4-26-2020 03:30 UTC
east bluff, CA

close ups:
camera ZWO ASI 290MM
Baader IR pass "685" nm
celestron 11" Edge HD
ASA DDM60
9/25/2020 03:05 UTC
east bluff, CA

Tuesday, October 20, 2020

Mars opposition 2020

 Here's mars shortly after 2020 opposition:

Mars RGB 10/14/2020 0758_5-UTC


Mars IR-RGB 10/14/2020 0758_5-UTC

Note that the bottom image, which uses IR as luminance gives sharper detail and contrast for the dark surface structures, but loses the detail at and around the southern polar cap as well as the bight bluish cloud? near the northern pole (upper right, which was visible in the eyepiece)

This year's opposition was much better than 2018 visually, as there was no dust storm obscuring the surface and it occurred at higher elevation for northern hemisphere observers.
https://astrowhw.blogspot.com/2018/07/mars-closest-approach-7312018.html

Image details:
10/14/2020  07:48-08:09 UTC
celestron 11" Edge HD
televue 2x barlow
ZWO ASI 290MM
ZWO RGB filters, Baader IR pass "685" nm
2x120 second captures each filter, 200 FPS
gain 351, exposure ~1 ms, 30% histogram
firecapture, autostakkert, winjupos, maxim, photoshop
elevation ~60 degrees
Eastbluff
Southern California