Jewel Box & NGC 6300 at 1728mm focal length

[Dennis]

Last night I used the Mewlon 180 F12 with Tak x0.8 Reducer/Flattener and SBIG ST2000XM to record the Jewel Box and NGC6300 at a longish focal length of 1728mm.

The Mewlon is a slowish ‘scope, even at F9.6 and the ST2K doesn’t have the highest QE, so the combination really struggled on NGC 6300 (ESO 101 25, PGC 60001) a Magnitude 11, Barred Spiral Hubble Type: SBb Galaxy located in Ara, with an apparent size of 5.5'x 3.5'.

I only managed 12x5mins Lum and 3x5 mins each RGB on NGC6300which is woefully inadequate for this galaxy from the light polluted suburbs of Brisbane. The Jewel Box was L 20x3 mins and RGB 5x3 mins each.

Both images are 1024x768 crops from the 1600x1200 originals.

Cheers

Dennis

[RickS]

The Jewel Box is very pretty, Dennis, especially with the funky Mewlon diffraction spikes! Looks like a nice little galaxy too but lots more data required.

[SkyViking]

Nice image scale! I especially like the Jewel Box. I've thought about taking a high magnification image of the Jewel Box, now I better get around to do it :) Thanks for the inspiration Dennis :thumbsup:

[Dennis]

Thank for your comments and feedback Rick & Rolf, much appreciated.:)

These efforts were part of a problem investigation from discovering some triangular stars from a previous session and I think I have identified some candidates for contributing to this:

I used 1 sec auto guider exposures at a focal length of 2160mm and I think the rig was chasing the seeing.
I fitted tube rings forward of the mounting puck and I think these introduced flexure.
I removed the brass pressure ring from my focuser and this skewed the camera in the draw tube.

Just working my way through these issues and I chose these shots as auto guiding towards the SCP is so forgiving.

NGC6300 also needs a "Rolf special" – a multi evening shoot with his gorgeous dark skies. I won’t be attempting this faint fella again from Brisbane!:)

Cheers

Dennis

[strongmanmike]

Looking good Deni...and I have no doubt that were there more funky spiders on more telescopes such diffraction patterns would not be noticed..we are creatures of habit and expectation :lol: Cool galxy too.

Mike

[SkyViking]

Lol, cheers Dennis.:lol:
However, my skies leave a bit to be desired unfortunately. I'm on the outskirts of Auckland and while I can easily see the MW and Magellanic Clouds it is still only around m20.40 around here according to a sky quality meter which I borrowed from Auckland Astronomical Society recently.

[Dennis]

Thanks Mike, I appreciate your comments.:)

The Mewlon diffraction spikes are quite useful to keep an eye on as each frame downloads and displays on-screen, as the vertical one usually drifts off-centre as the night progresses, a reminder for me to refocus due to temperature changes or other uncontrolled, evil gremlins in the imaging train!;)

Cheers

Dennis

[Dennis]

Ahh, thanks for that Rolf, for some reason I had a picture in my mind of you sitting under pristine, dark skies in the middle of unspoilt countryside! A testimony to the quality of the images you delight us with.:)

Cheers

Dennis

[SkyViking]

Thanks very much Dennis, I can clarify that it is unspoilt temperate rainforest but not entirely pristine skies :lol:
Still, we're really quite lucky in Auckland to have large wilderness areas so close to a major city centre with close to 1.4 million people!