NGC 1763 in the LMC

[naskies]

I've been exceptionally busy with uni (preparing for viva + written exams) which has limited my time with astro fun.

Here's a work-in-progress NGC 1763, one of the nebulae in the LMC commonly neglected in favour of the Tarantula :lol:

After exams, I'll try to collect a bit more OIII to smooth out the background and add some RGB subs for star colour.

Details: 16 x 60 min Ha (3 nm Astrodon) + 3 x 60 min OIII (8 nm Baader), GSO RC8, SBIG STF-8300M, EQ6PRO.

[pluto]

16x60min Ha!!!!:eyepop:
What a great target, very nice! :D

[RickS]

I've seen that in my LMC images from the FSQ-106ED, Dave. It's a very interesting object close up like that. Nice going! I look forward to the final version.

Cheers,
Rick.

[multiweb]

Nice one Dave. Great effort. :thumbsup:

[Stevec35]

Looks great already Dave. I'll look forward to the final version.

Cheers

Steve

[naskies]

Thanks Hugh. I forgot to mention that guiding was with a SX adaptive optics unit, so long subs are easy. Best part of all... the imaging was done while I was sound asleep :lol:



Thanks Rick! Funny that you say that, because I "found" this target while browsing a wide field LMC image recently.



Thanks Marc!



Thanks Steve!

[stevous67]

Lots of things can happen, or go wrong in an hour sub, even with AO running, so top effort with a nice result.

Steve :thumbsup:

[glenc]

Thanks Dave, a great image of one of my favourite nebula.

[Ross G]

Great looking closeup photo Dave.

Smooth and sharp.

60 minute exposures....wow!

Ross.

[tilbrook@rbe.ne]

Impressive Dave!:thumbsup:

It's got that 3D look to it.
60 minute subs!! You must have that mount humming.

Cheers,

Justin.

[pluto]

Nice :D
Great to see also as I'm thinking the STT-8300+AO and RC8 might be my next major purchase and I'm glad that I shouldn't have to upgrade from my EQ6.

[naskies]

Thanks Steve!



Thanks Glen! I came across a few of your posts on here while trawling the archives for reference images. I think I've accidentally stumbled across it through the eyepiece while hunting for the Tarantula and going "whoa".



Cheers Ross! A bit of a tough target at Brisbane's latitude and early in the season - the Ha subs were taken between 20 and 45 deg altitude. I tried for some RGB stars but they were a mess, so I'll wait until it's near the meridian over summer.



Thanks Justin! I actually "upgraded" to Greg Bock's former mount (http://www.iceinspace.com.au/forum/showthread.php?p=979292), and run far less weight on it than he did so I actually get pretty good stars at 1625 mm focal length even without AO. My original EQ6 (which I still have) is so bad that it needs AO at > 5 Hz to do the same :eyepop:



Yes, that set up would be capable of excellent results. Note that I only use 2x2 binning now because of the long focal length (including for the 60 min NB subs) - 1x1 is just too insensitive (slow), but it's good to have the option there for tiny planetaries.

I'd also recommend getting a quality refractor around 300 - 600 mm focal length for larger nebulae (Triffid + Lagoon, Orion + Running Man, Horsehead + Flame, etc).

[Paul Haese]

Impressive given the sub length. Heaps of detail. Maybe a bit dark in the background, but I will keeping an eye out for the further developments. How did you happen upon the notion to image for 60 minutes per sub? Did you find that 30 minutes was not producing enough signal?

[astronobob]

SX adaptive optics unit & RC scope, sounds a very practical combo for going deep Dave, great result :thumbsup: I can imagine your auto set-up working and you inside studying skin cells what-have-you, , Lol !
Great Effort and awesome result :thumbsup:

[pluto]

I have a SW ED80, which I love, but I have been tossing up between the RC or a nice WO 110 f7 triplet or similar. I just have to decide whether I want to chase those smaller objects, and deal with the extra challenges a long FL brings, or whether I want to image the same kinds of objects that I am now but with better glass. Unfortunately my budget demands that I not make the decision any time soon ;)
Either way it's good to know that I'm free to choose without having to worry about the extra outlay on a better mount!
Thanks for the advice :)

[naskies]

Thanks Paul. I agree about the background - this is just a quick process, and needs a bit of dynamic range compression for the bright central blobs.

I've just been following two principles for exposure length: expose-to-the-right and use ideal exposures when sky limited (overwhelm the read noise with sky background). The Astrodon filters really suppress both stars and sky background, so even with 60 min subs all the nebulosity is bunched up on the left side of the histogram with minimal sky background.

I did start with 20 min subs and while the bright areas of nebulosity came through fine, the background was very noisy and didn't improve even with long integration times such as 36x20 min (12 hours). With 12x60 mins, I noticed the background was much cleaner but I have a lot more thermal noise and hot pixels. I'd prefer a larger aperture scope and/or more sensitive camera, but for now longer subs are free :D

I think I read on here that you've ordered Astrodon filters? I think you'll find that with the same length subs as before, your histogram will be bunched up to the left compared to the wider filters.



Thanks Bob! Back to learning about macules, papules, plaques, patches, nodules, pustules, vesicles, ...



If you're a galaxy hunter, maybe go for the extra aperture of the RC8 or larger? If it were me, I'd love a WO 110 f/7 triplet. It'd give you great image scale and FOV for nebulae, and throwing in a GSO RC8 for smaller targets would be peanuts ($700-$800 used).

[strongmanmike]

60min subs, wow, pretty good...I'm a 5 and 10min man myself :)

Impact is what I see here, some processing/blending improvements here and there wouldn't go astray but the sheer Pow factor is pretty cool mate :thumbsup:

Mike

[marco]

A great and dramatic image of this object Dave, surely got a kick when looked at it :thumbsup:


Clear skies
Marco

[RobF]

Impressive (and dedicated) work Dave!

[naskies]

Cheers Mike. If I had a 12" f/3.8 scope, I'd be a 5-10 min man too ;) Yep, I agree on the processing - this was just a quick & dirty job, but I also have a lot to learn on that front too.



Thanks Marco!



Thanks Rob!

[DJT]

Great image Dave, like what you are doing. The detail is quite something.

Cheers

[naskies]

Thanks David!

[astronobob]

oooowhh yuuuck, thats discusting :eyepop:

[Leonardo70]

Great shot.

All the best,
Leo

[gregbradley]

I missed this one. Fantastic object choice. That is rarely imaged. A terrific result.

The 60 minute subs paid handsome dividends.

Greg.

[naskies]

Thanks Leonardo!



Thanks Greg! A tiny bit less rare now that Justin's imaged it too :lol:

[Bassnut]

Narley and smooth 3d effect there, and wow, 60min subs on an EQ6, well set up. Impressive altogether.

[lazjen]

Very nice - I'm also impressed with 60min subs. I might get game enough to try 10min subs sometime soon, so to me that sounds legendary. :)

[naskies]

Thanks Fred & Chris. With a well-tuned EQ6, software-assisted polar alignment, off-axis guiding, and adaptive optics, guiding and long subs is a no-brainer :)

[glenc]

James Dunlop was the first to see NGC 1763. He described it as "A very faint rather elliptical nebula, about 2' diameter. This is the preceding and largest of three nebula forming a triangle." Dunlop observed with a homemade 9" speculum reflector from his backyard in Parramatta in 1826.
https://picasaweb.google.com/110048826379679252146/Dunlop28?noredirect=1#5640113124865 331714

[naskies]

Thanks Glen. I had a look at this neb through my 10" dob over the weekend under dark skies. The three brighter nebs forming the triangle were easy to see, as was the central star cluster, but the ring around the star cluster was very, very faint. A great target for both imaging and observing :thumbsup: