Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Thursday, October 31, 2019

witch's broom and the veil

  here's the witch's broom nebula:



and the ghoul:

both are part of the veil supernova complex

haunting tale:
7,000 years ago, a massive star burned out, collapsed, and then exploded, creating a supernova.
several thousand years later, prehistoric man looked up in the sky and saw a bright light visible during the day
that lasted for weeks. 
(this was about the time the monolith arrived)

200 years ago, with the aid of the telescope, man discovered
the expanding cloud of gas created by the supernova.
it is very large (3 degrees, or 36x bigger than the full moon) and very faint.
the witch's broom (above) is one edge of the expanding cloud
the other side is shown below at a smaller scale
you can almost see a bow wave ahead of it:


here's the whole thing (click for full size):

Veil nebula
this is a 4 panel mosaic with a total of 32 hours of exposure time
taken over the course of 2 months

~700,000 years from now the expanding shock wave will hit our planet
what will happen to life was we know it?

the bright side (from NASA):
"Although only about one star per century in our Galaxy will end its life in this spectacular way, these explosions are responsible for making all chemical elements heavier than iron, as well as being the main producers of oxygen in the universe. Elements such as copper, mercury, gold, and lead are forged in these violent events. The expanding shells of supernova remnants mix with other clouds in the Milky Way and become the raw material for new generations of stars and planets. The chemical elements that constitute Earth, and indeed those of which we ourselves are made, were formed deep inside ancient stars and distributed by supernova explosions in nebulae like the one we see here".

P.S. recent data indicates heavy elements being formed by neutron star mergers in addition to super novae (confirmed spectroscopically) , something new under the sun. 

On that note:
happy halloween

Sunday, October 13, 2019

Jupiter Methane filter

after catching a glimpse of jupiter's great red spot starting to unfurl, i picked up a methane filter (which enhances the great red spot...and looks cool ) to see if i could better detect the activity.  it's a bit hard to wrap your head around what a methane filter does.  the short version is that high altitude clouds on jupiter (including the great red spot) appear very bright with a methane filter (detailed discussion below).

in the methane filter image below, there is high signal at the great red spot (a giant storm high up in the atmosphere), at a high altitude equatorial belt, and at polar clouds.  in contrast the signal is extremely low on the east and west sides where the light passes tangentially through extremely thick layers of methane: 
Jupiter 7/21/2019 05:54 UTC RGB left, Methane center, Methane(as red)-GB right


The swirls around the GRS (center) and red trail (right) might be related to the GRS unfurling: 
Jupiter 6/29/19 06:17 UTC, Europa upper left




Jupiter 6/27/19 05:23 UTC 

here's my take on methane filters.  methane (CH4 for you organic chemistry fans) is present throughout the atmosphere of the gas giants in our solar system.  it generally absorbs light in the red end of the spectrum.  the methane filter only passess light in a very narrow range around a specific *absorption* band of methane in the infrared (no green house gas comments please).  since the gas giants are full of methane, they actually appear very dark with a methane filter (in contrast, the jovian moons are extremely bright relative to jupiter with this filter as they have no methane).  so when sunlight hits jupiter and reflects back to us, the light travels through less methane where high altitude clouds reflect the light back (so less light is absorbed).  the higher the clouds, the brighter the signal (factor of 2 here since the signal is absorbed on the way in and out). 

here's a sequence of jovian moon europa (which has no methane atmosphere) passing across the surface of jupiter.  reflecting all the methane signal, europa is extremely bright in the methane images, in contrast to the dark disk where methane absorbs the light: 


conversely, europa is barely detectable in the visible light images as jupiter's surface shines so brightly: 


Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader methane 889 nm 8 nm bandwidth
celestron 11" Edge HD
East Bluff, CA
90 second captures, 2x binning for methane
no barlow

7/21/19
2 captures each filter
upsampled 2x for processing, then reduced to 60%
6/29/19
4 captures each filter, except 12 for methane
6/27/19
2 captures each filter

gain 351, exposure ~0.6-1.0 ms, 30% histogram, ~280 fps
methane exposure 111-240 ms, 3-8 fps

Tuesday, September 3, 2019

hetch hetchy night and day, yosemite

Here are shots of the hetch hetchy reservoir in the northwestern part of yosemite national park
Hetch Hetchy, night and day, Yosemite National Park


Here's a slightly brighter view of the falls and reservoir with the landscape lit by the setting moon.   the diagonal stripe mid frame is the milky way, slightly obscured by passing clouds on the horizon. 

among other things seen in this northern view are Cassiopeia, mid milky way,  and the andromeda galaxy to its right (see later images with annotations)

Here are a few hours of star trails:
the red leaves in the foreground were not turning in July, but briefly illuminated by my red flashlight while imaging. 

here's a video of the rising milky way, with some passing clouds as the moon set, followed by a reverse version with star trails, ending with the setting moon illuminating the hills. 



The dam kicked up quite a bit of spray.  i spent an embarrassing amount of time trying to capture a moonbow as the moon set.  the next morning the rising sun produced a beautiful rainbow at the same site--letting me know i was shooting from the wrong side of the spray.  DOH! 


Though there were no major meteor showers, we saw at least 4 an hour in the dark yosemite skies.  Only caught one with the camera:


Here's sagittarius and the milky way along with a few wandering planets shot from the dam


A bit to the right, here's scorpius with bright jupiter.



straight up we saw the summer triangle with the cygnus the swan mid milky way



In August, we back packed from Tuolumne Meadows to Grant lake (again in Yosemite). 
Here's a cell phone capture of my favorite constellation, Cassiopeia, the giant W, along with the milky way and the andromeda galaxy (same part of the sky as the earlier images). 
Cassiopeia from Tuolumne Meadows


here are sagittarius, saturn and the milky way rising at grant lake.


a final moon set thru haze at grant lake:



imaging details (for astrophotography nerds only):
many technical problems with these outings
the wide field images were plagued by my laptop switching to power saver mode several times grrr...
I missed focus on basically all of the DSLR images, hence the small scale.  the cell phone images showed some promise, but the phone's exposure time is limited to 10 seconds. on the plus side, it allows captures in raw mode, allowing for dark subtraction.
perhaps i'll try this again with a modern DSLR and dedicated wide field lens.

The Moment cell phone lens attachment gives a wider field of view and is faster.
though there was little chromatic aberration, there were severe star distortions at the edges requiring cropping :(



Hetch Hetchy wide field (night)
ZWO ASI 290MC
stock fisheye lens
Shutter=20.0s
Gain=351 (58%)
20 second exposures continuously from
11:43 PM 7/7/19 to 1 AM 7/8/19 AM PDT
Hetch Hetchy, Yosemite National Park, California

(day)
Samsung Galaxy Note 9
FL 4.3 mm f/2.4

Moon
Nikon D60
stock lens (18-55) @15 mm f/3.5
30 s
ISO 1600

Rainbow
Nikon D60
stock lens (18-55) @18 mm f/8
1/250 s
ISO 100

Meteor, Sagittarius, Scorpius, Cygnus
Nikon D60
stock lens (18-55) @18 mm f/3.5
30 s
cygnus 88x30 sec ISO 400
scorpius 8x30 sec ISO 1600
saggitarius 5x 30s ISO 1600
even with dark subtraction, there was significant amp glow especially on the cygnus shot, hence the desaturation.
sky watcher star adventurer mount (tracking stars)

cell phone Cassiopeia and Sagittarius
Samsung Galaxy Note 9 with moment Wide 18mm Lens (Magnification Ratio - .63X)
FL 4.3 f/ .945 ?
30x10 s
ISO 800

Tuesday, July 2, 2019

Jupiter at opposition 2019: great red spot unfurling

Jupiter reached opposition (directly opposite the sun) June 10th.  you can see it rising in the east after sunset.  It will get higher and higher in the evening sky over the next few months.

Here's my first Jupiter of the season from June 9th right before opposition:
Jupiter 6/9/2019 08:52 UTC
this infrared image enhances the great red spot and the mid equatorial zone (more about the latter later):
Jupiter IR-GB 6/9/2019 08:52 UTC

Recently, portions of the great red spot were found to be peeling off.

Here's a blink of the GRS at larger scale with and without IR enhancement:
Jupiter 6/9/2019 08:52 UTC

The enhancing red stripe is likely a section of the great red spot that has peeled off. 
Here's a time lapse of the great red spot taken by BQ Octantis, a member of the cloudy nights forum, imaging from the Australian outback:
posted with permission


A section of the great red spot appears to peel off on June 1 and then progress to the right.  

Here's an article at sky and telescope with more details and images.  
https://www.skyandtelescope.com/astronomy-news/jupiters-great-red-spot-unfurls-see-it-in-your-scope/


Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader IR pass 685 nm, Astronomik IR pass 807 nm
6/9/19 08:52 UTC
celestron 11" Edge HD
televue 2x barlow
90 second captures 4 each filter (2 for each of the IR filters)
gain 351, exposure ~3-6ms, 30% histogram, ~150 fps
IR 685 Shutter=4.831ms, FPS (avg.)=145
IR 807 Shutter=23.89ms, FPS (avg.)=41
corrector fogged up despite dew heater, blurring detail
so image is only 50% scale :(
807 nm images as sharp or better than 685 nm despite longer exposure, lower fps

Sunday, April 21, 2019

sunspot AR 2738 and a few proms

Despite being at solar minimum, a moderately large sunspot was well positioned mid April:
AR 2738 4/14/19 WL

AR 2738 4/14/19 Ha
AR 2738 4/14/19 Ha and WL

The following weekend as the spot rotated off the face to the edge, i watched very dynamic activity on the limb, including a prominence lifting off and a very bright ball of plasma:
Ha 4/20/19
...which i just missed with the camera :(

but there was a nice prominence on the opposite side:
Ha 4/20/19

Full disk view through light incoming clouds:
Sun Ha 4/20/19 through light clouds causing glare





Image details:
C11 edge on ASA DDM 80, baader film, baader continuum filter, IR/UV block filter
first light with C11 soloar filter, love the cooling fans, unfortunately seeing was poor
Lunt 60 PT on manual alt-azm mount
Eastbluff, CA

4/14/19 poor seeing (image reduced to 50%)
C11
19:45 UTC
ASI 290 MM
FPS (avg.)=147
Shutter=0.918ms
Gain=351 (58%)

Lunt double stacked
20:56 UTC
ASI 290 MM
FPS (avg.)=103
Shutter=9.699ms
Gain=67 (11%)

4/20/19
first prom
ASI 290 MM
22:55 UTC
second 22:58 UTC
20 second video
111 fps
Shutter=1.0 ms
gain 351
best 12%

full disk with light clouds
ASI 174 MM
23:09 UTC
45 fps
Shutter=10.00ms
Gain=225 (56%)


Saturday, April 20, 2019

Markarian's chain


Speaking of the Virgo supercluster, here's Markarian's chain, a photogenic string of galaxies in the Virgo cluster:
Markarian's chain 4/2010
including Messier 87 lower left
Here at low magnification, M 87 (featured in the prior post) is the nondescript elliptical galaxy in the lower left.

bonus feature:
close up of the "eyes", a pair of interacting galaxies in Markarian's chain
NGC4438 & NGC 4435
Note the disturbed dark lane and streaming outer stars in the left hand galaxy, resulting from gravitational interaction with it's neighbor


this is occasionally the basis for my avatar ;)


Details:
markarian's chain
FS60C @f/4, IDAS-LPR filter, SX H9, H9C.
Lum 45x5 min 223x1 min
RGB 101x5 min
los alamitos, CA 4/3-17/2010 bortle white skies

NGC4438 & NGC 4435
nexstar 8 gps, f/6.3 FR, H9C
350 minutes (70x5)
approximately 2/3 with IDAS LPR filter, 1/3 without
4/23,24,30/2006!
Los Alamitos CA
bortle white skies, mediocre seeing, worse transparency

Thursday, April 18, 2019

Messier 87 the smoking gun galaxy

Messier 87, the smoking gun, is a super giant galaxy--over a trillion  stars--in the constellation Virgo.  M 87 lies 55 million light years away, at the center of the Virgo supercluster which includes our local galaxy group. 

Images of the black hole at the center of M87 were released last Wednesday, 4/10/19.  Inspired by the image, I photographed the galaxy from my backyard that night. 

At low power, M 87 looks like a boring elliptical galaxy, just round blob of light (see following post).  This close up shot from 4/10/19 shows blue "smoke" rising out of the core to the right which is actually plasma ejected from the core as the black hole devours matter.  

M 87 close up
streak of blue plasma projects up and to the right
Needless to say, the resolution of this image is not fine enough to capture the black hole.  The scale of this image is 0.4 arc seconds (angular measurement, as in degrees, minutes, and seconds) per pixel.  However, due to atmospheric distortion, the resolution of the image is about 2.0 arc seconds (FWHM).  On a good night, i can capture images below 2 arc second resolution, the best i've ever captured (once) was just under 1 arc second.  For reference, the resolution of the Hubble space telescope is typically 0.1 arc second.  The resolution of the event horizon telescope that captured the black hole was .00002 arc seconds.  

Here's the Event Horizon Telescope image:
Event Horizon Telescope Image of the supermassive black hole (6.5 billion solar masses) in the center of the galaxy M 87


How can you get such amazing resolution? 
The resolution of a telescope is limited by it's diameter.  However, if you can combine the signal captured by multiple telescopes at the same time, the resolution is limited by the distance between the telescopes.  The event horizon telescope combined images captured by an array of radio telescopes all around the globe (including the south pole) giving an effective diameter approaching the size of the planet earth.  Interestingly, i've heard that the release of the image was partially delayed by having to physically transport a hard drive from the south pole (which cannot be easily reached all year round).  

The phenomena surrounding a black hole are truly amazing: of course at the event horizon no light can escape the gravitational pull of the black hole.  But beyond that is an area where photons themselves orbit the black hole multiple times.  creeping out from this are areas where light may bend 270 degrees: so if you look on the left side of a black hole, you'll see an image from the black hole facing left.  beyond that 180 degrees, so you'll see the image of our own galaxy reflected back, further out 90 degrees, so you'll see an image from the black hole facing right...
Here's a trippy youtube video simulating this phenomenon while two black holes are merging:


And here's an interesting video giving more detail on the light bending phenomena near a black hole:




Details:
8" LX200R, SX Trius 694 0.4"/px, ASA DDM60
astrodon LRGB E SERIES GEN-II
Luminance 4/10/19
12 of 46 120 second subs, 7 of 63 60 second subs
(threw out all with FWHM >5.5 pixels)
RGB 4/12/19
15x120 sec each channel
fair seeing (excluded ~2/3 subs)
the jet is very bright, the image is a simple linear stretch without sharpening
Eastbluff, CA Bortle white

EHT press release with more details on the black hole image:
https://eventhorizontelescope.org/

 A bit more science:
The Astrophysical Journal Letters
https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT