ASTRO: NGC 5033

On a recent outing to decent skies (April 9, with a about 1/3rd full moon
that would be no problem from my rooftop terrace but was obviously
brightening the sky at an otherwise dark sky) I imaged the large but faint
spiral NGC 5033 in CVn. Seeing was bad, I had to use 3x3 binning for
focusing to get a feeling for the "sweet spot".

Taken from an old russian airfield south of Berlin with a Meade 10" ACF at
f/8 on a G11 mount, Atik 383 camera, 11x10 minutes L, 4x10 minutes each RGB,
all binned 2x2.

http://ccd-astronomy.de/temp5/5033colourgut.jpg

Stefan

On 5/3/2011 3:49 PM, Stefan Lilge wrote:
On a recent outing to decent skies (April 9, with a about 1/3rd full moon
that would be no problem from my rooftop terrace but was obviously
brightening the sky at an otherwise dark sky) I imaged the large but faint
spiral NGC 5033 in CVn. Seeing was bad, I had to use 3x3 binning for
focusing to get a feeling for the "sweet spot".

Taken from an old russian airfield south of Berlin with a Meade 10" ACF at
f/8 on a G11 mount, Atik 383 camera, 11x10 minutes L, 4x10 minutes each RGB,
all binned 2x2.

http://ccd-astronomy.de/temp5/5033colourgut.jpg

Stefan


This one is harder than it would appear. It's on my reshoot list as I
my attempt is odd looking. Galaxy looks like I over did the smoothing
something severe even though I used less than normal. Most shots of it
look oddly smoothed. Must be the way it is. Still I think I can do
better than what I did. Even with your bad seeing you got more detail
in that tiny spiral and star at the very left edge center in your image
than I did! And you think my detail is good. You easily beat me on
that one!

What's the zenith limiting magnitude out there at the base? I take it
that its abandoned and thus dark. It doesn't take much moon to really
hurt the faint stuff in galaxies. I can handle a waxing moon until
about a day before first quarter but a day after last quarter is still
way too bright. I don't know why the difference. I try to image on the
opposite side of the meridian from the moon and high if it is low and
vise versa. Often I gather my color data on such nights and get the L
data on darker nights. Hasn't worked this fall with only one or two
sort of usable nights a month. I have a lot of RGB and no L to go with
it thanks to the weather always being cloudy during the dark of the
moon. A lot will have to wait until next year now. A bummer!


I've had too many such nights. When seeing is good I see a focus change
in only 25 microns at f/10. All focus formula say that my depth of
field is over 100. Saw a Sky and Telescope article last fall that also
said those formula are nice but experience says otherwise. They too
decided 25 microns made a difference at f/10. Anyway on a typical night
I can go 50 to 75 without seeing any change and on a bad one (all too
common) I can go 300 or more and nothing changes. Focus Max can't agree
as each time I run it it too comes up with a different focus point. On
a fair night it hits the same one every time. Not on my bad ones.

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

Rick,

the airfield was last used in 2007 as a setting for a Hollywood film
featuring Tom Cruise. When we see a plane in the sky we still like to make
jokes that it probably will land here :-)
The sky is nice dark without the moon, I have measured SQM-L values of 21.6
to 21.8. Certainly better than mag 6. In the night where I imaged NGC 5033
the sky was brighter, but I didn't have the SQM-L with me. I could see a mag
5.5 star in UMi, but the limiting mag was a bit better, probably around mag
5.7.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
On 5/3/2011 3:49 PM, Stefan Lilge wrote:
On a recent outing to decent skies (April 9, with a about 1/3rd full moon
that would be no problem from my rooftop terrace but was obviously
brightening the sky at an otherwise dark sky) I imaged the large but
faint
spiral NGC 5033 in CVn. Seeing was bad, I had to use 3x3 binning for
focusing to get a feeling for the "sweet spot".

Taken from an old russian airfield south of Berlin with a Meade 10" ACF
at
f/8 on a G11 mount, Atik 383 camera, 11x10 minutes L, 4x10 minutes each
RGB,
all binned 2x2.

http://ccd-astronomy.de/temp5/5033colourgut.jpg

Stefan


This one is harder than it would appear. It's on my reshoot list as I my
attempt is odd looking. Galaxy looks like I over did the smoothing
something severe even though I used less than normal. Most shots of it
look oddly smoothed. Must be the way it is. Still I think I can do
better than what I did. Even with your bad seeing you got more detail in
that tiny spiral and star at the very left edge center in your image than
I did! And you think my detail is good. You easily beat me on that one!

What's the zenith limiting magnitude out there at the base? I take it
that its abandoned and thus dark. It doesn't take much moon to really
hurt the faint stuff in galaxies. I can handle a waxing moon until about
a day before first quarter but a day after last quarter is still way too
bright. I don't know why the difference. I try to image on the opposite
side of the meridian from the moon and high if it is low and vise versa.
Often I gather my color data on such nights and get the L data on darker
nights. Hasn't worked this fall with only one or two sort of usable
nights a month. I have a lot of RGB and no L to go with it thanks to the
weather always being cloudy during the dark of the moon. A lot will have
to wait until next year now. A bummer!


I've had too many such nights. When seeing is good I see a focus change
in only 25 microns at f/10. All focus formula say that my depth of field
is over 100. Saw a Sky and Telescope article last fall that also said
those formula are nice but experience says otherwise. They too decided 25
microns made a difference at f/10. Anyway on a typical night I can go 50
to 75 without seeing any change and on a bad one (all too common) I can go
300 or more and nothing changes. Focus Max can't agree as each time I run
it it too comes up with a different focus point. On a fair night it hits
the same one every time. Not on my bad ones.

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

One just might try it. Many years ago there was a small airport near
the town I lived in along with a Air Force Base for B-47 bombers with a
10,000 foot (3050m) runway at the time. The small airport had an 1100
foot (335m) runway. One night a heavy transport was headed for the
base. He asked for verification on the runway length. When told it was
10,000 feet he said "That's the damn shortest 10,000 feet I've ever seen
and put it down at the little airport. Considering a base used a two
flash white light beacon while the private used a 1 flash he should have
realized this wasn't an Air Force base. Somehow all survived the
landing. They had to pull it out of a swamp. Then it was stripped of
all that could be removed including structural components not needed for
less than 1.2 G loads that could be removed. It was given 50 gallons of
gas, just enough to reach the base 11 miles away and a single volunteer
pilot of less than 55kg. The road off the end of the runway was closed
on a day of 40 mph headwinds. Powerlines dropped and he somehow got it
off and ran out of gas on approach to the base but there was a 2500
(760m) undershoot concrete strip which was just close enough for him to
glide to. Half the town turned out to watch them try and get it off.
The other half was there for the landing. I was in the first bunch as
my dad was a pilot whose plane was at the little airport and his hanger
had a perfect view of the end of the runway. He flew across the swamp
at 1 foot, same for the road but got it to 2 feet to clear a fence on
the other side of the road. More swamp for a mile. He was a good 50
feet up by the end of the swamp and finally climbing somewhat normally.
Doubt he got over 200 feet the whole time. We couldn't see past a
couple miles so had to listen to the radio to find out he made it. The
headwind that helped him get off was also a problem as he had to fight
it much of the way to the base costing valuable time and fuel.

A few years earlier a DC6 landing at the Omaha airport at night landed
at the unlit, no beacon, grass field in Council Bluff's Iowa (across the
Missouri river from the Omaha airport. It was a rainy night and he
sheered off the landing gear which stuck in the mud on impact.
Passengers were shook but only bruises from seat belts as the plane
stopped really fast with no gear and all that mud. Good thing as it
would have been in the river otherwise. That pilot was fired and lost
his commercial license. Don't know what action the Air Force took
against it's wayward pilot.

Rick

On 5/4/2011 5:53 PM, Stefan Lilge wrote:
Rick,

the airfield was last used in 2007 as a setting for a Hollywood film
featuring Tom Cruise. When we see a plane in the sky we still like to make
jokes that it probably will land here :-)
The sky is nice dark without the moon, I have measured SQM-L values of 21.6
to 21.8. Certainly better than mag 6. In the night where I imaged NGC 5033
the sky was brighter, but I didn't have the SQM-L with me. I could see a mag
5.5 star in UMi, but the limiting mag was a bit better, probably around mag
5.7.

Stefan

"Rick schrieb im Newsbeitrag
ster.com...
On 5/3/2011 3:49 PM, Stefan Lilge wrote:
On a recent outing to decent skies (April 9, with a about 1/3rd full moon
that would be no problem from my rooftop terrace but was obviously
brightening the sky at an otherwise dark sky) I imaged the large but
faint
spiral NGC 5033 in CVn. Seeing was bad, I had to use 3x3 binning for
focusing to get a feeling for the "sweet spot".

Taken from an old russian airfield south of Berlin with a Meade 10" ACF
at
f/8 on a G11 mount, Atik 383 camera, 11x10 minutes L, 4x10 minutes each
RGB,
all binned 2x2.

http://ccd-astronomy.de/temp5/5033colourgut.jpg

Stefan


This one is harder than it would appear. It's on my reshoot list as I my
attempt is odd looking. Galaxy looks like I over did the smoothing
something severe even though I used less than normal. Most shots of it
look oddly smoothed. Must be the way it is. Still I think I can do
better than what I did. Even with your bad seeing you got more detail in
that tiny spiral and star at the very left edge center in your image than
I did! And you think my detail is good. You easily beat me on that one!

What's the zenith limiting magnitude out there at the base? I take it
that its abandoned and thus dark. It doesn't take much moon to really
hurt the faint stuff in galaxies. I can handle a waxing moon until about
a day before first quarter but a day after last quarter is still way too
bright. I don't know why the difference. I try to image on the opposite
side of the meridian from the moon and high if it is low and vise versa.
Often I gather my color data on such nights and get the L data on darker
nights. Hasn't worked this fall with only one or two sort of usable
nights a month. I have a lot of RGB and no L to go with it thanks to the
weather always being cloudy during the dark of the moon. A lot will have
to wait until next year now. A bummer!


I've had too many such nights. When seeing is good I see a focus change
in only 25 microns at f/10. All focus formula say that my depth of field
is over 100. Saw a Sky and Telescope article last fall that also said
those formula are nice but experience says otherwise. They too decided 25
microns made a difference at f/10. Anyway on a typical night I can go 50
to 75 without seeing any change and on a bad one (all too common) I can go
300 or more and nothing changes. Focus Max can't agree as each time I run
it it too comes up with a different focus point. On a fair night it hits
the same one every time. Not on my bad ones.

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




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