Mars closest approach 7/31/2018

Here's mars at closest approach for the 2018 opposition:

Mars 7/31/18 8:21 UTC

Visually it looked like a bright orange disk with poles visible.  seeing was not great, but Cassini was easily resolved on Saturn, so assuming the lack of contrast/detail is the dust storm.  

An IR filter cut thru the dust bringing out more detail on the face:

Mars 7/31/18 8:21 UTC IR

Lastly, here's the RGB color with IR applied as luminance:

Mars 7/31/18 8:21 UTC IR-RGB

For reference, here are the individual color channels.  note the high contrast polar caps in the blue:

red

green

blue

Image details:
7/31/18 08:07-08:35 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 (3 ms blue), 30% histogram
firecapture, autostakkert, winjupos, maxim, photoshop
elevation 30 degrees
Eastbluff
Southern California

mercury take 2

mercury, is difficult to observe and image.  since it's so close to the sun, it is usually only seen low in the horizon just before or after sunset.  visually, mercury looks like a tiny orange half moon.  the reddening results from atmospheric diffraction, due to its low position in the sky. 
more info at prior blog on mecury

in my recent imaging session, with mercury relatively high in the sky (thanks to a computerized mount and my house blocking the sun), it appeared to be a white partial disk.  some have been able to demonstrate surface detail on mercury with IR filters (which are less subject to atmospheric seeing effects).  unfortunately, i was not able to pull out any detail, but i did get a nice sharp half moon 😃. 

Mercury 7/15/2018 IR 2:23 UTC

with a lot of imagination, there may be a slight blotch to the right, but i'm keeping "detail on mercury" as a future project.  opportunities at dusk occur when it is furthest from the sun: ~November 6 2018, next February 27 or June 23 2019.

a few more images:

Mercury 7/4/2018 IR 3:14 UTC

Mercury 7/3/18 (red filter) 3:15 UTC

here's my 2006 effort low on the horizon, barely visible as an orange dot:

Mercury 10/19/2006

Imaging details:
Celestron 11 edge HD
Camera=ZWO ASI290MM
7/15/18
4x5 minute captures
~400 fps
best .25% of ~500,000 frames
Shutter=0.1 ms
Gain=361 (60%)
Histogramm=30%
Baader IR pass "685" nm
2x barlow and
upsampled 2x

Eastbluff
Southern California

Jumpin' Jupiters

Had a run of the best seeing I've ever experienced in my location during the unusually warm humid weather of June and early July this year.  Here are a bunch of Jupiter images and some comments on imaging techniques during the session.

C8 2x barlowed with mono camera.  though shot on a different night, it suggest a dramatic improvement imaging with the barlow compared to a recent image without the barlow (prior post):

6/11/18 04:25 UTC

C 11 first light, poor collimation (compounded by fogging of filters i think) left large offset halos requiring much work in photoshop for removal 
wound up getting fogged out so not all color was captured, but was clearly able to demonstrate better detail in 2x barlowed images compared to 1x upsampled.
2x barlow gave greater than 2x magnification:

6/25/18 04:47 UTC upsampled 2x
do not click for full size

6/25/18 04:47 UTC 2x barlow
do not click for full size

collimated C 11 getting better:

6/26/18 04:46 UTC
click for full size

6/27/18 06:32 UTC
click for full size

7/2/18 05:53 UTC
click for full size

um, the seeing was very good on 7/2-3:

7/3/18 04:32 UTC

seeing party over 😞 (still as good as captures from last year):

7/4/18 07:19 UTC

seeing encore:

7/14/18 05:08 UTCclick for full size

On the new scope:
celestron edge HD 11
11" aperture, FL 280 mm (f/10)
3.75 inch central obstruction (34%)
28 lb
tempest equilibration fans installed

why not the meade 12?
also a good scope, better focuser, bigger aperture, though 13 lbs. heavier. 
It didn't play well with my persnickety ASA mount.  in particular cool down requires opening up the back and/or placing a cat cooler in the scope, leading to weight imbalance causing the motors to let go, or requiring the use of a hex wrench to lock the mount in place...in a recessed socket under the scope...in the dark. 


imaging conclusions:
1. it's 90% seeing (second best image was barlowed c8)
2. barlow makes a noticeable difference in many different circumstances despite increasing exposure length and decreasing fps
3. venting tube currents seems necessary for the large SCT's.
4. mono noticeable improvement over color
5. stacking up to 18 minutes smoother than 9
6. preliminary stack/rejection and centering batch mode in PIPP speeds up processing and seemed to center slightly better than direct to autostakkert, improving winJupos work flow (thanks sam)
7. wide field with moons very helpful for size/rotation determination, even for jupiter in winjupos
8. sharpening before or after winjupos combine made no difference given the same alignment

issues: still getting some variability in size/placement in winjupos
refocusing between filters seemed to help.  check with bahtinov mask

Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters

6/11/18
celestron nexstar 8 GPS (8" SCT on a wedge)
televue 2x barlow
~70 sec captures, 2 each filter
gain 351, exposure ~5-9.4ms, 30% histogram, ~90 fps
drizzle 1.5x

6/25/18
celestron 11" Edge HD
60 second captures 2 each filter with and without televue 2x barlow
gain 351, exposure ~0.6-1ms, 30% histogram, ~200 fps
barlowed 3-5ms ~147 fps
fogged out, poor collimation
barlowed vs resample 2x

6/26/18
celestron 11" Edge HD
60 second captures 2 each filter
gain 351, exposure ~0.6-1ms, 30% histogram, ~287 fps
resample 2x

6/27/18
celestron 11" Edge HD
televue 2x barlow
90 second captures 2 each filter
gain 351, exposure ~3-6ms, 30% histogram, ~150 fps
drizzle 1.5x

7/2/18
celestron 11" Edge HD
televue 2x barlow
90 second captures 2 each filter
gain 351, exposure ~3-6ms, 30% histogram, ~150 fps
resample 2x

7/3/18
celestron 11" Edge HD
televue 2x barlow
90 second captures 3 each filter
gain 351, exposure ~3-5.7ms, 30% histogram, ~130 fps
drizzle 1.5x

7/4/18
celestron 11" Edge HD
90 second captures 2 each filter
gain 351, exposure ~.5-1.8ms, 30% histogram, ~200 fps
drizzle 3x, then reduced to 1x :(

7/14/18
celestron 11" Edge HD
televue 2x barlow
90 second captures 4 each filter (18 min)
gain 361, exposure ~3-5 ms, 30% histogram, ~150 fps

Eastbluff
Southern California

conjunction junction venus and luna

conjunction: two astronomical objects coming together.


disclaimer: i'm not much on terrestrial photography and my DSLR battery died as i focused, so cell phone, point and shoot and lots of photoshop. enough excuses...

artsy composition thru trees (see the earthshine?):

California sky, with palm tree, pink clouds, airplane and low smog:

OK back to astrophotography

venus and moon during twilight (which or course didn't fit in the same telescopic field) photoshopped together:

Ultra Venus:

Imaging details:

venus and moon
7/15/18 03:18 UTC
Celestron 11 edge HD
Camera=ZWO ASI290MM
venus with
Baader U filter: 350nm, bandwidth 60nm (320-380nm)

landscapes
7/15/18 8:40-9:20 PM pacific
wide view
cell phone, Droid Turbo
tree view
Sony DSC-RX100M3
f/2.8, iso 6400 26 mm

Eastbluff
Southern California

MARS, BRINGER OF...dust

While you may have read some of the hype surrounding the most favorable Mars viewing since the 2003 opposition (which helped inspire my interest in astronomy), there's a less encouraging story surrounding Mars recently.  
Recall Mars is the only planet in the solar system who's surface detail can be seen telescopically, and that Mars is only in a favorable position for viewing from earth every 2 years (26 months).  More on Mars in my 2013 blog entry
Unfortunately, what started as a small dust storm on a portion of the surface has evolved into one of the largest dust storms in recorded history, completely obscuring surface detail for the last few weeks.  While planetologists find this fascinating, it's a bummer for amateur astronomers, as all that can be seen is a featureless orange disk.  

Here's an image of mars from 2005.  The snaky white structure just right of center is a dust storm:

Mars 10/19/05 08:00 UTC

Here's my first image of mars this year.  The entire surface is obscured by dust, you can see a hint of blue surface structure and polar caps:

Mars 7/14/18 08:00 UTC

An infrared image cuts thru some of the storm, showing a bit better contrast:

Mars 7/14/18 08:00 UTC, infrared

Consider the fate of a manned Mars mission dependent on solar power during a month long planet-wide storm...Potato!

Some nice before and after images can be seen in this sky & telescope article

Nevertheless, the storm seems to be lessening, so there may be more to see during opposition on 7/23/18. 


Image details:
10/19/05 08:00 UTC
nexstar 8 gps, 2.5x powermate
toucam pro ii
1/500 exposure 3000 frames
Los Alamitos, CA

7/14/18 08:00 UTC
celestron 11" Edge HD
televue 2x barlow
ZWO ASI 290MM
zwo RGB filters, Baader IR pass "685" nm
90 second captures each filter, 200 FPS
gain 361, exposure ~1 ms (3 ms blue), 30% histogram
elevation 30 degrees
Eastbluff
Southern California

Ultra Venus

Venus is covered by a thick layer of clouds which shines brightly, making it the brightest planet in the sky.  See prior Venus overview.  Visually it appears to be a featureless white disk which goes thru phases like the moon.  However, UltraViolet light shows rapidly moving clouds, thought to be composed of sulfuric acid and aerosols(wikipedia):  

Venus Visible light 7/3/2018 ~3:30 UTC

Venus Ultraviolet colorized 7/3/2018 ~3:30 UTC

Venus Ultraviolet grey scale 7/3/2018 ~3:30 UTC

Venus Ultraviolet 7/2/2018 ~3:30 UT

Venus Ultraviolet 7/14/2018 3:35 UT

Venus Ultraviolet colorized  7/14/2018 3:35 UT

No detail in this one:

Venus Ultraviolet 7/4/2018 ~3:30 UT

Couldn't pick up any detail in IR:

Venus Infrared 7/3/2018 ~3:30 UTC

Imaging details:
imaging in UV was complicated by light loss and poor focusing of UV light by glass elements in the image train, increased UV susceptibility to atmospheric distortion, and turbulent air near sunset when Venus is visible.
typical capture
Celestron 11 edge HD
Camera=ZWO ASI290MM
Frames captured=109386
Duration=400.921s
FPS (avg.)=272
Shutter=3.206ms
Gain=361 (60%)
Histogramm=33%
Baader U filter: 350nm, bandwidth 60nm (320-380nm)
Baader IR pass "685" nm

Eastbluff
Southern California

summer saturnalia

Still celebrating a summer Saturnalia.  I've had a run of the best seeing locally in several years.  It's a great time for planetary observing with Venus at sunset, Jupiter transiting at a gentlemanly 9 pm, Saturn near opposition around midnight, and then a blazing Mars rising in the east, approaching  opposition later this month.  

Here are more images from my recent capture of the Saturn's polar hexagon.  Infrared, up-sampling the video by a factor of 3.  

Saturn with north polar hexagon, infrared image 6/26/18 7:45 UTC

Here's a north polar projection, showing the hexagon:

The hexagon was not visible in my RGB image (click on image for full size):

Saturn RGB 6/26/18 7:45 UTC

Here, I've added infrared as luminance to bring out the hexagon in the RGB image.  You can also see that the banding on the disk is much more prominent in infrared (click on image for full size).

Saturn with north polar hexagon, RGB with IR luminance  6/26/18 7:45 UTC

Lastly, here's an annotated wider field:

The cause of the hexagon is still not clear.  One theory is that a hexagon forms where there is a steep variation in the speed and viscosity of atmospheric winds.  The hexagon was blue when it was discovered by the voyager probe in 1981, but has changed to a gold color.  More information on the hexagon at wikipedia.  

The north polar hexagon can only be imaged from earth when Saturn's north pole is tilted towards us.  It was maximally tilted towards us last year and will be tilting away for the next 15 years, when the south pole will be facing us, then begin tilting back.  So you can see the source of my urgency in capturing it.  

image details
celestron 11" Edge HD
ZWO ASI 290MM
zwo RGB filters, Baader IR pass "685" nm
processed in PIPP
upsampled 3x in autostakkert
sharpened in registax
combined in winjupos
6/26/18  07:45 UT
Eastbluff
Southern California