ASTRO: NGC 6914

This is one of those NGC objects with an identity crisis. Some sources
say it is the uppermost blue reflection nebula. Others say it is the
entire complex that runs well out of my field with a center down out of
my field. NED takes the former view, SIMBAD the latter. SIMBAD refers
to the three reflection nebula, south (bottom) to north as [RK68] 100,
[RK68] 101 and [RK68] 102. The last being what NED says is 6914.
Whatever it is a pretty area. To get the reflection nebula I had to do
this as LRGB. Trying to include H alpha just ruined the reflection
nebula color and dimmed it considerably. So I added time to the L image
to bring up the signal. This was a bear to process due to it being done
at the worst part of my flat problem but taking the frames over several
nights due to clouds helped. The donuts were all over the place and
sigma reject got rid of some, but not all, of the problem. Fortunately
donuts don't hurt the color data like they do the luminosity data so I
could survive those repairs without it showing.

I'm leaving town in a couple hours so if you have any comments I'll get
to them when I get back next week. This is one of those trips that may
get me back by Sunday or mid week, just depends on factors beyond my
control.

I see I screwed up the file name. I used 10 10 minute frames not 8 as
the file name would indicate. Oh well. That happens when you are in a
hurry.

14" LX200R @ f/10, L=10x10', RGB=2x10' all 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".

Excellent image - will have to rethink my minimalist approach to data
collection.

FWIW, the reflection nebulae are Vdb 131/132, Uranmetria list the
emission part as DWB-100-5-9.


On Thu, 25 Oct 2007 10:07:23 -0500, Rick Johnson
wrote:

This is one of those NGC objects with an identity crisis. Some sources
say it is the uppermost blue reflection nebula. Others say it is the
entire complex that runs well out of my field with a center down out of
my field. NED takes the former view, SIMBAD the latter. SIMBAD refers
to the three reflection nebula, south (bottom) to north as [RK68] 100,
[RK68] 101 and [RK68] 102. The last being what NED says is 6914.
Whatever it is a pretty area. To get the reflection nebula I had to do
this as LRGB. Trying to include H alpha just ruined the reflection
nebula color and dimmed it considerably. So I added time to the L image
to bring up the signal. This was a bear to process due to it being done
at the worst part of my flat problem but taking the frames over several
nights due to clouds helped. The donuts were all over the place and
sigma reject got rid of some, but not all, of the problem. Fortunately
donuts don't hurt the color data like they do the luminosity data so I
could survive those repairs without it showing.

I'm leaving town in a couple hours so if you have any comments I'll get
to them when I get back next week. This is one of those trips that may
get me back by Sunday or mid week, just depends on factors beyond my
control.

I see I screwed up the file name. I used 10 10 minute frames not 8 as
the file name would indicate. Oh well. That happens when you are in a
hurry.

14" LX200R @ f/10, L=10x10', RGB=2x10' all binned 2x2, STL-11000XM,
Paramount ME

Rick

"Rick Johnson" wrote in message
...
This is one of those NGC objects with an identity crisis. Some sources
say it is the uppermost blue reflection nebula. Others say it is the
entire complex that runs well out of my field with a center down out of
my field. NED takes the former view, SIMBAD the latter. SIMBAD refers
to the three reflection nebula, south (bottom) to north as [RK68] 100,
[RK68] 101 and [RK68] 102. The last being what NED says is 6914.
Whatever it is a pretty area. To get the reflection nebula I had to do
this as LRGB. Trying to include H alpha just ruined the reflection
nebula color and dimmed it considerably. So I added time to the L image
to bring up the signal. This was a bear to process due to it being done
at the worst part of my flat problem but taking the frames over several
nights due to clouds helped. The donuts were all over the place and
sigma reject got rid of some, but not all, of the problem. Fortunately
donuts don't hurt the color data like they do the luminosity data so I
could survive those repairs without it showing.

I'm leaving town in a couple hours so if you have any comments I'll get
to them when I get back next week. This is one of those trips that may
get me back by Sunday or mid week, just depends on factors beyond my
control.

I see I screwed up the file name. I used 10 10 minute frames not 8 as
the file name would indicate. Oh well. That happens when you are in a
hurry.

14" LX200R @ f/10, L=10x10', RGB=2x10' all binned 2x2, STL-11000XM,
Paramount ME

Rick

Great image, Rick. The area around the blue and the dark nebulas have more
detail than any other image I've seen of this region. My scope wants to be
like yours, Rick. :-)

George

"Rick Johnson" wrote
...
This is one of those NGC objects with an identity crisis. Some sources
say it is the uppermost blue reflection nebula. Others say it is the
entire complex that runs well out of my field with a center down out of
my field. ...........

Great image Rick! Really neat! Well worth the processing effort!

When thinking about these "NGC Questions" I think you have to consider what
would show visually in a 10 to 15 inch scope under very dark conditions.
That's what most of the NGC records.

Here's Dr. Corwin's notes from the NGC Project website:

NGC 6914 is the northern-most of three similar nebulae, probably all
reflection nebulae -- the show up best on the POSS1 blue plate.
Interestingly, the area on the red plate is dominated by a large HII region,
centered 20-30 arcmin to the northeast of N6914. Are the reflection nebulae
part of the same system of gas and dust, or are they merely superposed along
the line of sight? I suspect the former, but of course can't say for sure.

Beautiful image Rick. The colour contrast is striking.

Stefan

schrieb im Newsbeitrag
...
Excellent image - will have to rethink my minimalist approach to data
collection.

FWIW, the reflection nebulae are Vdb 131/132, Uranmetria list the
emission part as DWB-100-5-9.


On Thu, 25 Oct 2007 10:07:23 -0500, Rick Johnson
wrote:

This is one of those NGC objects with an identity crisis. Some sources
say it is the uppermost blue reflection nebula. Others say it is the
entire complex that runs well out of my field with a center down out of
my field. NED takes the former view, SIMBAD the latter. SIMBAD refers
to the three reflection nebula, south (bottom) to north as [RK68] 100,
[RK68] 101 and [RK68] 102. The last being what NED says is 6914.
Whatever it is a pretty area. To get the reflection nebula I had to do
this as LRGB. Trying to include H alpha just ruined the reflection
nebula color and dimmed it considerably. So I added time to the L image
to bring up the signal. This was a bear to process due to it being done
at the worst part of my flat problem but taking the frames over several
nights due to clouds helped. The donuts were all over the place and
sigma reject got rid of some, but not all, of the problem. Fortunately
donuts don't hurt the color data like they do the luminosity data so I
could survive those repairs without it showing.

I'm leaving town in a couple hours so if you have any comments I'll get
to them when I get back next week. This is one of those trips that may
get me back by Sunday or mid week, just depends on factors beyond my
control.

I see I screwed up the file name. I used 10 10 minute frames not 8 as
the file name would indicate. Oh well. That happens when you are in a
hurry.

14" LX200R @ f/10, L=10x10', RGB=2x10' all binned 2x2, STL-11000XM,
Paramount ME

Rick