ASTRO; SH2-155 Cave Nebula up close and personal

This nebula, mostly emission (red) with some reflection characteristics
as well (blue) is located in Cepheus. It is part of the Cepheus B
molecular cloud. The illuminating stars are considered to be HD 217086
at the top of my image, an O7 star and HD 217061 above center, a B1 star
(very slightly smaller and cooler). IR images show a tremendous amount
of star formation going on in the cloud (darker portions of my image).
These are thought to be triggered by HD 217086. It is outside the cloud
itself. Radiation from the star is thought to drive a compression wave
into the cloud triggering star formation in the interior while blowing
away the cloud's outer layers. Chandra/Spitzer observation in X-ray and
IR light show this is happening. The region is thought to be about 2400
light years from us.

This is a reshoot of this object. I did it very poorly early in my
digital career. It was time for a better effort. Still not what I
wanted. I wanted a lot more color data but after two months of
something preventing it I apparently gave up. Maybe I can get the
needed data later this fall. For now I put together what I had. I used
the RGB data to try and bring out the reflection parts of the nebula and
H alpha data to bring out the ionized hydrogen in the area (red). With
too little RGB the hydrogen is dominating more than I wanted. Still the
reflection regions are sort of there.

Due to the image eating up a lot of bandwidth and its lack of fine
detail I reduced the image scale to 1.5" per pixel to keep file size
reasonable without too much compression.

14" LX200R @ f/10, L=4x10'+2x30'Ha (Ha blend at 40%), R=2x10'+40% Ha (to
allow reflection nebula to show), G=2x10' and B=2x10'+10% Ha,
STL-11000XM, Paramount ME

Due to the lack of RGB data I had to retard the H alpha levels quite a
bit not to totally lose the reflection parts of the nebula.

Rick
--
Prefix is correct. Domain is arvig dot net

I meant to attached the full frame reduced to 1.5" version not the
cropped version.
Correct version this time

Rick

You rarely see this object this close.
You did a great job maintaining the reflection part while adding the Ha
channel.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
.com...

I meant to attached the full frame reduced to 1.5" version not the
cropped version.
Correct version this time

Rick