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pvelez
22-08-2012, 11:02 PM
I've decided to try my hand at something a bit fainter - so here is a crop of NGC 6744. Its a work in progress - I think I need twice as much data. And that annoying blue gradient is still there - I can beat it down with more signal I guess.

Not sure of precise integration times - roughly 2 hours L and 1 each of RGB

Taken with QSI 583wsg on RC8 and processed in PI

Comments and criticisms welcome

Thanks for looking

Pete

allan gould
22-08-2012, 11:16 PM
It's a difficult galaxy to image and needs a lot of data from a dark site. Try the QSI at 2x2 binning for all filters for your next image

pvelez
23-08-2012, 07:55 AM
Yes Allan, I think I picked a challenging target.

Sadly, this is binned x2. My site very not dark - I'm about 7km from the CBD so its LP city.

I do think I've not drawn enough out of the L - I'll have a more serious play with it this evening.

Pete

tilbrook@rbe.ne
24-08-2012, 07:00 PM
Hi Pete,

You really did pcik a challenging target!
I have dark skies, and had trouble getting decent data.
You have pulled a fair bit of detail so far.

Cheers,

Justin.

whzzz28
24-08-2012, 08:00 PM
You wouldn't expect it to be so hard as a mag 9.0 galaxy, but for some reason it is.

What exposure lengths are you using?

I got a bit of data on 6744 at Astrofest but not too much and found i had trouble getting detail with 10min subs.
Right now i am imaging it from home with 15min subs and it's still a bit dull (waiting for NGC253 to come up).

pvelez
24-08-2012, 08:01 PM
Thanks Justin

its a challenge - more a processing challenge. I find I am too impatient usually and want to move onto something new each session. I've just started to use CCD Autopilot and PI so its a chance to let the computer manage the imaging while I have dinner, remind the family what I look like etc and then try and drag a decent image out of the data.

Its plugging away again this evening. Tonight I plan to wait till NGC 253 is up, set the computer to do its work and go to bed - a first for me

Will let you know how it goes

Pete

madbadgalaxyman
26-08-2012, 10:45 PM
Agreed, Nathan, 9th magnitude sounds bright.....
but just giving the total brightness of a galaxy says nothing about the actual angular size of the object in the sky. The long axis of this galaxy is at least 25 arcminutes; it is nearly half a degree across!!
So while NGC 6744 might be as bright as a 9th magn. star, it is like a 9th magnitude star spread over a vast area of sky......

cheers,
Robert

pvelez
27-08-2012, 08:17 AM
Nathan,

with the LP at my place its 180 seconds on R and G, 288s on B and 300 on L.

Way too short unless I just plug away at it for hours.

For some reason, the more data I add, the harder it is to process. I guess I need to keep at it.

I also switched over to NGC 253 - its far easier!

Pete

Ross G
28-08-2012, 06:01 AM
Hi Pete,

A great attempt, especially from light polluted Sydney.

I have tried imaging it from Coonabarabran and not gotten any more detail than you have.

What suburb are you imaging from?

Ross.

pvelez
28-08-2012, 08:03 AM
Ross

I'm in Haberfield - only 7km from the CBD. Its pretty heavy duty LP but with lots fo shorter subs, I can make sopme inroads on these sorts of targets

Pete