Thread: ASTRO: SH2-188
View Single Post
  #4  
Old December 26th 07, 05:12 PM posted to alt.binaries.pictures.astro
Richard Crisp[_1_]
external usenet poster
 
Posts: 985
Default ASTRO: SH2-188

now I *really* like that image Rick

the lower left looks interesting too.

i need clear skies and good seeing for the 18"!


"Rick Johnson" wrote in message
...
This is a very weird planetary nebula. The central star is well down
and to the left of the center of the loop, much like Comet Holmes
nucleus appears closer to the the bow shock than the center of its coma.
In the case of Holmes, the solar wind is pushing the front of the coma
back toward the much denser nucleus. In the case of SH2-188 the
planetary is flying through the interstellar medium at a high rate and
its leading edge is forming a bow shock, and thus is far brighter than
it would otherwise be and far closer to the "central star". Or so the
model says. It is the tiny blue star a bit to the left and up a tad
from the prominent yellow star near the inside edge of the brightest
part of the arc.

I took this through the heavy ice layer we have hanging in the air now.
The result was all sorts of nasty gradients. I'm not good at removing
them so they are still there. I need to get Russ Croman's GradientX
removal tool. I did it the hard way with pseudo flats in Photoshop. It
only sort of worked. I might as well be imaging from Manhattan Island
for all the crap the ice crystals put in my shots. It was -32C when I
took this shot! I imaged at -34C one night last year so this isn't a
record but darned close.

I used H-alpha frames as the Lum image, I used a combination of the same
H-alpha frames and 2 red frames for the red frame and normal green and
blue though added a bit of H-alpha to the blue in an effort to help the
stars. Seemed to make them too blue however but the stars look better
against the nebula than when I leave that step out.

14" LX200R @ f/10, L=2x30' H-alpha, R=L+2x10' red, GB= 2x10' RGB were
binned 3x3 H-alpha binned 2x2, STL-11000XM, Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".