NGC3247 comparison in Ha and NIR

[sjastro]

A quick 10 minute exposure of the field around NGC 3199 in NIR (near infrared) with a 300mm lens revealed that NGC 3247 is a fairly bright object in NIR.

The differences when NGC3247 is imaged in Ha and NIR is dramatic.
Due to the longer wavelength, NIR is able to penetrate the heavily obscured field and reveal may more stars.

Of particular interest to astronomers is Westerlund 2 (http://en.wikipedia.org/wiki/Westerlund_2) which is the compact cluster in NGC 3247. It is located just above the main body of the nebula.
In the Ha image it is very obscured but conspicuous in NIR.

Image details
NGC 3247 in Ha 2.5 hrs Ha (L) 1 hr R, 1 hr G,1 hr B BRC-250 ST-X10ME.
High resolution:- http://members.iinet.net.au/~sjastro/ngc3247Ha.html

NGC 3247 in NIR 6 hrs NIR (L) 1 hr NIR (R), 1 hr G,1 hr B BRC-250 ST-X10ME.
High resolution:- http://members.iinet.net.au/~sjastro/ngc3247NIR.html

Clear skies

Steven

[Stevec35]

Interesting stuff Steven. After a long delay I've finally added the NIR filters into my system and am currently looking for targets. You might have given me one.

Cheers

Steve

[strongmanmike]

Wow, big difference Steve

Fred would positively hate that filter, it'd give him nightmares! :lol:

Mike

[gregbradley]

Interesting work Steven. The NIR really reveals a lot more.

Greg.

[madbadgalaxyman]

Outstandingly more interesting in the NIR than in the visual regime, especially the cluster!

Me and Dana have been obsessing about the cluster Westerlund 2 in a number of threads:

http://www.iceinspace.com.au/forum/showthread.php?t=119363

http://www.iceinspace.com.au/forum/showthread.php?t=119608

http://www.iceinspace.com.au/forum/showthread.php?t=120201

The might call me madbadgalaxyman, but Dana is definitely the Mad Cluster Man; he will spend multiple nights trying to glimpse a vanishingly faint Star Cluster, and he looks up all of the science about his target of observation.

cheers,
Robert

[sjastro]

Thanks Robert.
I used to be an observer of faint objects. Modern day astroimaging is the easy way out, instead of training (and straining) yourself in the "art" of visually detecting faint objects.




Thanks Greg.
I'm pleased I have been able to work out a procedure where I can obtain good colour balance with a filter that blocks out light in the visible spectrum.



Thanks Mike. What are Fred's objections?



Thanks Steve.
My ST-10XME is a good match with the Astrodon NIR filter.
Are you using the Astrodon filter with your setup?

Clear skies

Steven

[pvelez]

Man that NIR filter really cuts through the dust - like a hot knife through butter.

Thanks for that

Pete

[sjastro]

Thanks Pete.
You are producing a fine collection of images with your 12.5" CDK.

Steven

[sjastro]

Here is a blend of the NIR and Ha data.

The cluster Westerlund 2 shows better resolution.
http://members.iinet.net.au/~sjastro/ngc3247Ha_NIR.jpg

Steven

[strongmanmike]

Hmm someone hasn't been paying attention on this forum :shrug: :lol:

Fred is notorious for removing the stars from his images..I think this is even recorded in the National library :question: :lol:

Mike

[sjastro]

I see.

What happens if he is imaging an open cluster, globular or any object devoid of nebular detail.

Do they turn out as per the attachment?

Regards

Steven

[Shiraz]

interesting comparo Steven. I guess that the wider bandwidth of the NIR filter will accentuate the stars a bit more than Ha, but it definitely looks as though the better transmission also helps.

[sjastro]

Thanks Ray,

The wider bandwidth does help in revealing more stars in the NIR image.
In the nebular regions, photons in the NIR range are relatively unscattered compared to the shorter wavelength visible range photons.

Regards

Steven

[strongmanmike]

Well...essentially, yes :lol: thing is, he doesn't image clusters...can't tell'im though, that's how he likes'em :)

[Stevec35]

Thanks Steve.
My ST-10XME is a good match with the Astrodon NIR filter.
Are you using the Astrodon filter with your setup?

Clear skies

Steven[/QUOTE]

I use the Astrodon NIR Luminance and colour filters

[sjastro]

I also use the Astrodon NIR luminance and RGB filters.
Rather than using the Astrodon NIR "colour filters", I map the NIR to R and use the same exposure time as for the G and B exposures.

Regards

Steven

[Paul Haese]

An interesting look at the same object through different sets of eyes. Not sure which I like the best. NIR is an intriguing view.

[sjastro]

Thanks Paul,

My preference is for the NIR image because it is different.
The Ha image is just a run of the mill image which is no different from the hundreds of other images of the same object.

Clear skies

Steven