Log in

View Full Version here: : NGC 346 and NGC 371 in the SMC


SkyViking
25-09-2016, 05:24 PM
Here is a relatively quick snap of my favourite nebula in the SMC: NGC346. I took this narrowband image on the side during a couple of moonlit nights while working on my Antlia Cluster deep field. The seeing was not very good though, so the resolution did not end up as crisp as I would like. Nevertheless, while waiting for clear skies I've now finally managed to dust off this data from 2015 and put an actual image together :)

Link to large image (http://www.rolfolsenastrophotography.com/Astrophotography/Nebulae/i-fS9GBNz/X3)
Link to full resolution image (6.4MB) (http://www.rolfolsenastrophotography.com/Astrophotography/Nebulae/i-fS9GBNz/O)

About the image:
In the Southern constellation Tucana lies the Small Magellanic Cloud, a dwarf galaxy orbiting our own Milky Way galaxy and home to the bright star-forming nebula and cluster NGC 346 depicted here in this image together with its neighbour NGC 371. The densely populated star field covering the entire field of view is part of the central bar structure in the SMC. The image is constructed from exposures in three very narrow (3nm) wavelength bands corresponding to the emission profiles of ionised Hydrogen, Oxygen and Sulphur. The red hues correspond to ionised Hydrogen emission (H-Alpha), and bluer colours are ionised Oxygen (OIII).
NGC 346 is a beautiful bright emission nebula in the central bar of the SMC. It is easily identifiable even in small telescopes as the brightest nebula in the SMC, and shows as an extended spiral shaped swirl surrounding a brighter centre which is home to the central star cluster. Near the core this nebula has a curious sharply defined edge curving around the cluster. The strong stellar winds from the young hot stars in the cluster have blown out the surrounding gas into diffuse filament-like structures extending far from the core region. It is interesting to imagine how impressive this magnificent nebula might have looked like if it was located in our own galaxy instead of in the SMC some 210,000 light years distant. A detailed close-up image of this nebula (https://www.spacetelescope.org/images/heic0514a/) is available from the Hubble Space Telescope.
The neighbouring NGC 371 (to the right) is a large and diffuse star cluster, surrounded by a glow of emission which appears intensely blue in this narrowband image. The cluster itself has a visual diameter of 7 arc minutes, corresponding to a real physical diameter of 350 light years.

Image details:
Date: 29th Jul, 21st Aug, 29th Sep 2015
Exposure: Ha:OIII:SII: 220:190:70 mins, total 8 hours @ -30C
Telescope: Homebuilt 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: strodon 3nm Ha, OIII, SII
Taken from my observatory in Auckland, New Zealand

Hope you enjoy!

Regards,
Rolf

Atmos
25-09-2016, 06:00 PM
Very nice Rolf! When you said relatively quick snap I was expecting some 20-30 hours ;)

It is an interesting region of the SMC. I got about an hours worth of Ha around this region a while back with plans of getting something more substantial but it hasn't happened yet.

:thumbsup:

RickS
25-09-2016, 07:37 PM
I've been a fan of NCG 346 since I imaged it from my driveway with a RC10. Lovely detail, Rolf, and the contrast between the two objects is very cool!

Cheers,
Rick.

el_draco
25-09-2016, 08:26 PM
Exquisite... Like a super fine lace...:thumbsup:

spiezzy
25-09-2016, 08:39 PM
It is hard to believe that this is an object in another galaxy and you have imaged it sooo good I have to have another look
cheers Pete :thumbsup:

Tony_
25-09-2016, 11:00 PM
Another brilliant image Rolf!
One of the best I have seen of this - so much detail I wouldn't have recognized it.

Tony.

SimmoW
26-09-2016, 04:52 AM
Superb work Rolf, such tight stars too! Thanks for being such an inspiration to us.

strongmanmike
26-09-2016, 07:40 AM
Yeah very nice Rolf....for a quicky ;)

Nice colours

Mike

Placidus
26-09-2016, 09:49 AM
Rolf, that's superb. Most particularly the processing of the shock fronts is excellent. (We were always rather proud of our shot. Now we have to go and do it all over again.)

What colour mapping did you use?

Best,
M & T

Peter Ward
26-09-2016, 11:20 AM
Once again an example of masterful technique from one of the best around.

Nice one:thumbsup::thumbsup:

gregbradley
26-09-2016, 11:25 AM
Superb Rolf. Nice composition really sets this off.

Greg.

Stevec35
26-09-2016, 10:20 PM
Looks great Rolf! Inspires me to revisit this area again myself. I'm always in awe of your imaging ability.

Cheers
Steve

marc4darkskies
27-09-2016, 12:03 AM
Not bad for a snapshot Rolf! :thumbsup: It could use more data of course but the colour and composition is quite lovely!

Cheers, Marcus

Retrograde
28-09-2016, 11:19 AM
Nothing much to add to the previous comments except to say that it is a lovely image.

multiweb
29-09-2016, 05:03 PM
Great shot Rolf. :thumbsup: Where did you get all those clear nights from?