IC5148 Spare Tyre Nebula in NB

Bassnut (Fred) · #1 26-08-2014, 05:58 PM

Hi Guys

IC5148 Spare Tyre Nebula in NB mapped as NII:Ha:NII:OIII (LRGB). Click here for big.

Taken on an RCOS 10" RC Scope at f9, SBIG STXL6303E Camera and PME mount at itelescopes Siding Spring Observatory.
Processed with CCDstack, Star Tools and Photoshop.
35 hrs Total. 34 off 3nm Ha subs 40min.. 14 off OIII 3nm subs 40min . 7 subs NII 3nm 40 min subs.

Their is no SII, so NII sufficed to add difference.

On this object for me, megadata and dark skies didnt reveal the OIII halo Rick and Martin just managed to capture at AT ALL, nix, nothin, nada. Don Goldmans rendition shows it brilliantly. I did try. Small apature finally caught up with me, damb

. Perhaps if I did another 50hrs of OIII I might get a squeek. Nup, cant be bothered

.

el_draco (Rom) · #2 26-08-2014, 06:11 PM

Never seen that before. FUNKY!

Peter Ward · #3 26-08-2014, 06:16 PM

Looks nothing like my mid-section.....hence this is good

Bassnut (Fred) · #4 26-08-2014, 06:40 PM

Thanks guys. I dont know why it isnt imaged more, its very bright (albiet smallish). Its one of those PN thats so bright it needed down curving to reveal detail (except the magical OIII halo, a real challenge).

RickS (Rick) · #5 26-08-2014, 07:00 PM

Nice image, Fred! It's a pretty little thing.

I'm surprised you didn't get a sniff of halo. My tally is now 56.5 hours of OIII and while not at Goldman 20" levels of detail the halo is very clear. I can see a bit of it in the Ha as well. I'm now doing 1 hour subs but started with 30 mins.

Cheers,
Rick.

Bassnut (Fred) · #6 26-08-2014, 07:20 PM

Well, you did well Rick, buggered if I can see anything. I only got 7 40min subs with no moon, the other half were next to full moon. Maybe thats the prob. 56.5 hrs just on OIII is just nuts

. I admire your persitence. Well worth the effort on this in particular, its turned into a bit of a hero status challenge few have dared to try

. 1hr subs!. That might be the key. Geez, thats hard work, I might be forced to do that

.

RickS (Rick) · #7 26-08-2014, 07:35 PM

I'm doing OK for someone without an obsy, Fred

A 20" scope seems to help a lot though.

Stevec35 (Steve) · #8 26-08-2014, 10:55 PM

Nice shot Fred. I've imaged this thing from time to time and just recently started getting data with a 3nm OIII. I got almost 4 hours and was starting to see the brightest part of the halo after heavy stretching of the data. Still a long way to go to get anything like Don's

Cheers

Steve

strongmanmike (Michael) · #9 27-08-2014, 11:28 AM

Excellent image Fred, love the colour

As far as integration time...have to draw the line somewhere

Mike

LewisM · #10 27-08-2014, 12:06 PM

Fred,

Have you got an image of this that's not black-clipped? Might help to extract any faint halo - it could well be hiding in there.

Bassnut (Fred) · #11 27-08-2014, 01:37 PM

Well, having looked at Steves stretch, I had another go at OIII super stretch myself. Turns out when you do that, moon glow really does make a big difference so I had to ditch half the subs (semi moon is generally OK with OIII without crazy stretching). What Im left with is 7 40min subs= 4.6hrs which is not a whole lot for this with a 10". Im thinking its an interesting exercise, but to produce a really smick pic like Dons on my 10" is just going to be too long. Like you say Mike, have to draw a line somewhere. I dont like leaving a challenge though, grrr, might attack it another time.

Its not often I stretch this much, tried a few things, Liberator (arcsinh) and much curving in PS seemed to work the best, although what I think is the halo in this pic is pretty tenuous. No other processing was done.