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Old 07-04-2013, 06:56 PM
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madbadgalaxyman (Robert)
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Join Date: Mar 2011
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Quote:
Originally Posted by gregbradley View Post
That's an interesting comparison Steven.

Its an interesting galaxy.

Greg.
Hi Greg,

Because NGC 7793 is an Sd-type galaxy and it is not a giant galaxy in terms of its total luminosity, the extinction from dust is small within NGC 7793;
therefore this galaxy is an ideal target for relatively short-wavelength (800nm-1000nm) infrared observations by amateurs;
The light from the central star cluster is a lot more obvious in Steven's NIR image.....so it seems that even short-wavelength NIR imaging is able to "dig out" the cluster from the intervening dust and other confusing material.

Just for fun, here is an NIR image of one of the most unusual and hard-to-understand members of the "mildly-to-moderately perturbed" galaxy population, the galaxy NGC 2442.
This image was taken in J + H + K bandpasses (1.2 microns + 1.6 microns + 2.2 microns) with the Gemini-South telescope:

Click image for larger version

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I am unaware of any amateurs doing 1.2 micron imaging, as it requires specialized equipment;
but don't you love the way that low-extinction >1 micrometer images give a sort of "X-ray" of the complex structure of a galaxy?!

Best regards,
Robert

Last edited by madbadgalaxyman; 07-04-2013 at 07:07 PM.
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