Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

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.

Thursday, August 9, 2018

martian mountains

recent mars images:
Mars 8/7/2018 07:45 UTC RGB
CM = 84.9
CL = -10.0
Infrared as luminance:
Mars 8/7/2018 07:45 UTC IR-RGB
with more heavy handed processing in my latest image Olympus Mons, one of the tallest mountain in the solar system, can be seen thru the dust.  
Olympus Mons
Mars 8/7/2018 07:45 UTC RGB

Though less distinct, three mountains of the Tharsis range can also be seen:
Tharsis Montes
Mars 8/7/2018 07:45 UTC RGB
Mount Olympus can also be seen in this image a few days earlier, though less clearly.  
Mars/Olympus Mons 8/4/2018 08:45 UTC IR-RGB
CM = 126.2
CL = -10.2

Mars 8/4/2018 08:14-08:50 UTC IR
Imaging details:
reviewed prior images while there seems to be a slight increase in contrast, my processing has become more heavy handing, yielding more details; it's still pretty much a featureless orange disk with a polar cap visually.
8/4/2018 08:45 UTC
CM = 126.2
CL = -10.2
8/7/2018 07:45 UTC
CM = 84.9
CL = -10.0
celestron 11" Edge HD
televue 2x barlow
ZWO ASI 290MM
ZWO RGB filters, Baader IR pass "685" nm
8/4 4x120 seconds
8/7 2x120 second captures each filter 8/7
200 FPS, gain 351, exposure ~1 ms (3 ms blue), 30% histogram
firecapture, autostakkert, winjupos, maxim, photoshop
elevation 30 degrees
Eastbluff
Southern California

Tuesday, July 31, 2018

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

Sunday, July 29, 2018

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 ðŸ˜ƒ. 

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