Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Saturday, July 26, 2014

filaprom

a solar prominence is typically a structure seen on the edge of the sun against the black background of space.  it often looks like an arch.  it consists of hydrogen plasma held off of the surface by magnetic fields. 

a solar filament is a large dark line seen across the face of the sun.  again hydrogen plasma held off the surface, but over the surface facing the observer, rather than on edge. 

in a sense, they are two sides of the same coin:
the filament absorbs the intense light from directly beneath then re-radiates it in all directions, with only a small amount heading directly on a line to the observer. This is why filaments appear dark on the solar disk. On the edge, we see the weaker emission component of the filament against a dark background.

that being said, i had difficulty visualizing filaments as the same structure. 
this is in part due to the fact that most images which show prominences are processed in order to lighten them compared to the surface to show more detail, so prominences always seem lighter. 

...until i caught a filaprom.  a filament that continues off the edge of the solar disk, clearly showing a dark line arching up over the surface:


2/16/14 newport beach, ca
DMK 51, 2.5x Powermate, Lunt 60 PT B1200
*manually guided on an altazmuth takahashi teegul mount.
took quite some time to process as software would not track well on solar image moving all over the field

Sunday, July 13, 2014

lost disk in color

what color are the Ha (hydrogen alpha) images of the sun?
hydrogen alpha is red, but viewing thru my solar scope, it looks reddish orange to me
no idea why, the filter is clearly red.

the images below are composites, combining a short exposure which picks up the bright surface detail
with a longer exposure burning out the center in order to pick up the faint prominences projecting off the edge of the disk.  
when combining these the prominences typically appear brighter than the disk, an artifact of processing in an attempt to bring out the faint detail in the prominence

in the first colorized version below, i used orange for the central structure and pure red for the prominences
in an attempt to correct for this brightening:




seemed like a good idea, but a bit of the detail in the prominences is lost 
here's a more aesthetically pleasing version with yellow flames shooting off the surface:



Friday, July 4, 2014

4th of july fireworks from the lost disk

back in may i took a quick look at the sun and saw multiple prominences erupting around the disk.  one of which looked like it was lifting off, so i zoomed in on it and was lucky enough to catch a lift off (prior entry).

after processing the lift off images, 
i looked at all the full disk images 
and discovered all the images occurred after the lift off was complete, missing multiple prominences

found the original full disk image from the start of lift off
misfiled on my hard drive so here it is:





brief animation (single disk frame with multiple prominence images)



i also found one more frame for the start of the close up animation
here's a small version:



color versions later

happy 4th

5/4/14 newport beach, ca

DMK 51, Lunt 60 PT B1200, ASA DDM60 
images captured ~ every 5 mintues