Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

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

Tuesday, February 12, 2019

A red flame

Captured a few solar prominence images between clouds this weekend with a hydrogen alpha scope .  I typically process these as black and white for maximum contrast, but red (the actual color) seemed most appropriate today:
Solar Prominence 2/9/2019
Here's a prominence from the next day.  I cranked the exposure to bring out some of the faint detail.  
Solar Prominence 2/10/19
Same prominence with shorter exposures:
Solar Prominence 2/10/19
wider crop for fun:

Image details:
Lunt 60 PT on manual alt-azm mount
ASI 290 MM
Eastbluff, CA 2/9/19  22:03 UT, 2/10/19 19:05 UT

2/9/19
double stacked
20 second video 60 fps
Shutter=2.786ms
best 25%

2/10/19
single stacked
20 second video 48 fps (full frame by mistake)
Shutter=2.379ms to 20.58ms
best 25%

Monday, October 8, 2018

spacex falcon 9 10/7/2018 launch

Why the 10/7/2018 falcon 9 launch was special:

1. it was launched from vandenberg airbase aiming south over the ocean
so it could be seen all the way from los angeles to san diego
2. the launch took place after dark, so the bright rocket could be seen well
3. it was done shortly after dark, so as the rocket rose above the shadow of the earth the exhaust was back-lit by sunlight, glowing brightly in the sky, presenting a cinematic view to los angeles and orange counties
4. the first stage rocketed back to vandenberg, landing at the airbase--the first ground landing of a falcon rocket on the west coast--"the falcon has landed" crowed spacex launch control


falcon-9 10/7/2018

In this image the cone (upper left) is the second stage of the rocket heading into orbit with its satellite payload.  
to the right of this, the exhaust (above the earth's shadow) is brightly lit by the sun.
The bright spot to the right of the palm tree is the first stage rocketing back to vandenberg, you can see a swirl of maneuvering thruster exhaust adjacent to it.  

another shot, later on:

I assembled a series of stills sandy captured with her compact hand held camera into a rudimentary animation:

For information on future launches, you can subscribe to this email list
http://mailman.qth.net/mailman/listinfo/launch-alert
which will send launch alerts, as well has information on the more spectacular launches


image details
Sony DSC-RX100M3
f/1.8, 1/10 sec, iso 3200 9 mm
corona del mar, CA
10/7/2018
the clouds broke just in time to give a clear view of the launch, then returned
photoshop, topaz denoise for the still shot

Wednesday, October 3, 2018

Solar minimum

the magnetic activity of the sun has an 11 year cycle:
at its peak, there are frequent sunspots, flares, etc.  while at minimum, not much is happening which is good for astronauts and satellites, not so good for aurora watchers and solar imagers.  interestingly the cycle was discovered in 1843 and then traced back to the earliest observations of sunspots by galileo.  we're now approaching solar minimum (2019).   

Here's an image of the sun from 8/25/18
Sun Ha 8/25/2018 with reverse polarity sunspot AR 2720

though difficult to detect in this hydrogen alpha image, there are pairs of small sunspots in the bright patches towards the bottom of the image.  AR 2720 to the left and AR 2719 to the right.  

the left hand pair (AR 2720) was noted to have reverse polarity and thought to be a harbinger of the next solar cycle.  However, subsequent analysis suggests that the pair were not part of the new cycle, based on their position on the solar surface.  

interestingly, the folks who study this closely are ham radio operators, as solar activity blanks out their radios.

Image details:
Ha full disk Lunt 60 PT/50 DS double stacked
zwo ASI 174MM
1.194 ms exposure
gain 223
15 frames captured
8/25/18 21:50 UT
adding an IR/UV blocking filter did not seem to have much effect (was wondering if there's some leakage)

this was also first light for a new camera which allows full disk imaging of the sun with my Ha scope.  unfortunately the frame rate was less than i'd hoped for, so still working on this...new USB cable and checking high speed seems to have helped 

Monday, October 1, 2018

sunspots in white light vs hydrogen alpha

Here's an image of a sunspot grouping comparing the standard "sunspot" visual filter image with a hydrogen alpha image:
Active solar region 1/11/2015 Ha vs white light




Here's a time lapse in Ha, nothing too dramatic, but there is some motion. 
Ha time lapse 1/11/2015 23:04-23:26 UTC
Imaging details/discussion:
found this one clearing out the hard drive
Ha close up Lunt 60 PT single stacked, on grab & go alt-azm mount, zwo asi 120mm-s
time lapse 19 frames over 22 minutes

the white light capture was done with an 8" SCT, baader photographic film with and without an IR/UV cut filter. the IR/UV cut filter improved contrast
20 second capture
FPS (avg.)=138
Shutter=2.869ms
Gain=73


Sunday, September 23, 2018

leo triplet

the leo triplet is a group of 3 galaxies popular with amateur astronomers as all 3 can be seen in the same telescopic field: M 65, M 66, and NGC 3628.  

they're also all quite photogenic (click on images for larger size):
Leo Triplet 2/2018

Closer view composited with close up images from years past:
Leo Triplet 2/2018 etc



the tragedy of the leo triplet is that the image scale required to fit all 3 doesn't do justice to these great galaxies. so here's the "leo double", the closest pair of the group:
M 65 and M 66

Bonus features:  
Asteroid 600 Musa wandering through the field:
asteroid 600 Musa near NGC 3628 
To my surprise, though i was unable to bring it out in processing, i see a hint of NGC 3628's tidal tail in an aggressive stretch from my bortle white skies, the unusually good transparency must have helped:
hint of the tidal tail of NGC 3628: stars streaming to the right
I combined the data from a  2018 wide field capture with my prior close up views from years ago:
M 66 HaRGB 2010
M 65 2009

NGC 3628 2007
just for fun here's my 2005 image:



Image details:
wide field
FS102, SX Trius 694 FL 627.3 mm, 1.49"/Pixel unbinned
astrodon RGB E-series filters
ASA DDM60
2/19-3/18/2018
L 457 x 1 minute
R 20 x 3 min, G 8 x 3 min, B 17 x 3 min
transparency and seeing unusually good for the luminance, much worse for color, so color was not incorporated into the luminance image.
bortle white skies
eastbluff, CA

M 65
LX200R 8" @f/10, SX AO, IDAS-LPS/CS 10 nm Ha filters; H9, H9C
L 46x10 min, RGB 22x20 min
4/18-4/29/09, Bortle white skies, los alamitos, CA

M 66
8" LX200R, IDAS LPR/Astrodon 5nm Ha filter, SX AO, SX H9/H9C
lum 92x300 sec, color 14x1200 sec, Ha 29x1200 sec (something to do with the moon out).
los alamitos, CA 3/16-24/2010, bortle white skies, excellent transparency for the area (southern CA at sea level) for luminance.

NGC 3628
4/12-17/07
los alamitos, CA
N8 GPS, F/6.3 FR @~1280mm, SX AO @~4Hz, IDAS LPR, H9C
45x20 minutes

Older triple:
4/5-12/2005
N8 GPS, canon digital rebel
the joy of amp glow
learning calibration, processing, gradient removal with images plus

Wednesday, August 22, 2018

fisheye perseids, star trails, and galactic fun

A fisheye lens is an ultra wide angle lens that can view the entire sky at once, but with strong visual distortions at the edges (straight lines become curved).  originally developed for meteorology (weather, not meteors), astronomers have taken them up for...meteors, not weather.  the wide view allows the camera to capture shooting stars anywhere in the sky.

so just for fun, on the evening of the Perseid meteor shower, i aimed a video camera (which came with a stock fisheye lens) at the sky and recorded images all night long.  bear in mind that my skies are extremely light polluted: the milky way is not visible and only the brightest stars of constellations can be seen most nights.  The situation was worsened by recent forest fires.

individual perseids:
over 7 hours (until clouds rolled) i only caught 4 bright meteor trails that would have been easily visible in my skies (and a hundred airplanes).  The first, and brightest, occurred at just after midnight:
Perseid meteor 8/13/2018 12:11 AM PDT
faint doted line mid frame is an airplane

Here's a blink of all 4 processed to remove light pollution/sky glow and bring out the stars:
meteors at 12:11 AM, 1:08 AM, 2:55 AM, and 3:50 AM PDT. 
clouds rolled in at 4 AM, peak viewing time :(
a mosaic combining the images of each:
4 perseids and an airplane
can you find cassiopeia, perseus? 
pleiades? andromeda galaxy?

here's a cropped version with the pertinent constellations outlined:
note that, allowing for fisheye lens distortion, they all point to Perseus.   

and yes that faint white band in the middle of the image is the milky way:  
180 x 20 second frames aligned on our galaxy
cleaner crop:


another cool thing you can do with a fisheye lens is wide field star trails: shooting pictures of the sky all night long on a tripod will demonstrate the rotation of the stars across the sky, centered around the northern celestial pole.  though my camera chip isn't big enough to capture the entire sky in one image, the diagonal will reach all the way from polaris in the north to mars skimming the southern horizon:
note polaris (lower left) rotating slightly around the north celestial pole and a bright perseid to it's right. 
the thick bright trail (top right) is mars on the southern horizon.
the gaps result from pauses writing to disk and removal of frames with airplanes :(

a version with the air traffic upstaging the perseids
(slight shift in the camera position):
The bright trail just inside mars (upper right) is saturn
here's a mesmerizing video showing the progress of the star trails:


selfie/warm-up from the night before:
star trails 8/12/2018
can you see my T-shirt and blurred head moving thru a long exposure?
dark shirt next time

clouded out at the end, so i guess this is true meteorology:



disambiguation:
apparently aristotle considered anything falling from the sky: rain, snow, sleet, hail, rocks, fireballs, hellfire...a meteor, hence the confusion.

image details:
ZWO ASI 290MC
stock fisheye lens with home made cardboard dew shield and kendrick dew heater
Shutter=20.0s
Gain=100 (16%)
20 second exposures continuously from
9 PM 8/12/18 to 4 AM 8/13/18 AM PDT (until clouded out)
Eastbluff
Southern California

processing the mosaic and milky way image was challenging due to the distortions at the edge of the fisheye lens and significant light pollution gradients.
maxim was not up to the task, so i resorted to registar which did an amazing job aligning/warping images for the combined shots.

i had no flats, so used the hubble trick, creating flat via a median combine of 1000 different light frames giving a smooth background without stars to correct the uneven illumination of the fisheye:
median combine of all images
still limited by heavy gradients liberal use of photoshop including gradient xterminator was required.