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