Thread: ASTRO: NGC 3938
View Single Post
  #2  
Old May 16th 07, 08:42 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
external usenet poster
 
Posts: 3,085
Default ASTRO: NGC 3938



Stefan Lilge wrote:
NGC 3938 is probably my favourite galaxy, so I waited for a good night
to reshoot it. Unfortunately I had some focus drift during the exposure
series, which didn't allow me to use the full potential of the very good
seeing I had. I sharpened the image only slightly as there wasn't enough
signal for any hard processing.

Taken from the middle of Berlin with an 8" SCT at f/6.5, G11 mount,
SXV-H9 camera, 38x5 minutes.

The picture can also be found at
http://ccd-astronomy.de/temp/3938-38x5gut.jpg

Stefan

------------------------------------------------------------------------


That's one that has been on my list but never got taken. My notes say
it has lots of HII regions "Like beads on a string." Looks like I'll
have trouble resolving those beads. They are 5" in size per my notes,
look smaller in your shot. I doubt I'll get seeing any better than
yours however.

I can't begin to take a shot without refocusing every 5 or 10 minutes
most nights. Temperature can drop rapidly. Ground is sand so it cools
fast like in the desert but the water doesn't. That sets up my bad
seeing as the two collide. I finally bit the bullet and bought a
temperature compensating Robo focus unit. That has allowed me to go to
10 minute frames, longer and stars burn in too much. Now I only check
the focus when going to another object. Usually it is right on though
once in a while it will have moved off center. Still in focus just not
centered in the narrow range of good focus. Many nights I never do
alter it once set. Well worth the big bucks with this scope anyway.

I'll have to wait for next year to try this guy as it's too far west for
me. I have better seeing the farther east I look. To the west of the
meridian I have a lot more water to look over and the house roof is warm
if it was a sunny day adding to the seeing woes. If I get just the
right night in the next week I might be able to catch it. So far
nothing but clouds this new moon. 5 days and counting -- no rain of
course, just clouds. Trees leaf out then die from lack of water. They
say if we get rain in the next couple weeks they'll recover. But the
birch and poplar appear to be in deep trouble just adding to the fire
danger here. Never seen so many clouds with so little rain to show for
it. Pine are going back to winter mode which means they won't dry out
so much but they can't fight the pine bore. Usually their sap will
drown them out but no sap in winter mode so the bore's do their damage.
I can hear them in some of my trees chomping away from the start they
got last year with so little rain. Looks like I'll have lots of firewood!

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".