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Old August 5th 07, 02:45 AM posted to alt.binaries.pictures.astro
Richard Crisp[_1_]
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Default ASTRO: 29 hours of High QE imaging of M27

No helium filter used for this image Rick

Sulfur, Hydrogen and Oxygen

it has been very difficult to get any nights the past month. Maybe two or
three hours on a good night, perhaps a single 20 minute on a not so good
night.

it takes a long time on the wallclock to log nearly 30 hour of exposure this
time of year

the really perverse thing is that the seeing has been excellent over the top
of the fog but the fog is between me and the skies....




"Rick Johnson" wrote in message
...


Richard Crisp wrote:
I began this over the July 4th holiday and took my most recent data last
night, Aug 3

This is 12 hours of [SII], 10 hours of [OIII] and 7 hours of Halpha

It was shot using the TK1024 powered FLI Dream Machine camera (1kx1k
@24x24 micron pixels at about 85% QE) using 4.5nm Cust Sci emission line
filters on the Stinger 450 classical cassegrain using a Lumicon Giant
Easy Guider with focal reducer for a focal length of 3366mm (~f/7.1). You
just can't beat those TK1024 chips and other such similar chips for going
really deep. The combination of the high QE, the deep wells and the big
pixels, it really makes for a fast camera that is just wonderful for deep
emission line imaging with tight filters.

I am intrigued by the sulfur channel data (red in this palette). I am
seeing detail I've not seen previously in shallower exposures.

I may take some more exposures, but am getting a bit tired of this object
after shooting it for the past month.

http://www.narrowbandimaging.com/m27...2hao3_page.htm


Looks like most of the outer shell is oxygen with a bit of helium and not
much sulfur. Interesting how it is somewhat segregated into areas like
that. You have had a lot more good nights than I have! I get an hour
here and there of sort of clear with horrid seeing. Not a summer for
imaging so far anyway.

Rick


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