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Old 16-08-2018, 08:47 PM
Placidus (Mike and Trish)
Narrowing the band

Placidus is offline
 
Join Date: Mar 2011
Location: Euchareena, NSW
Posts: 3,719
IC 1274 BigToe in Rhaspberry (HOO) and Hubble (SHO) palettes

We think this is gorgeous in HOO palette: IC 1274, or BigToe in H-alpha (mapped to red) and OIII (mapped to cyan). As before, a mosaic with about 80% panel overlap because our FOV isn't quite big enough for the whole thing.

To 7 hours of H-alpha We've added 10 hours of OIII. Stars are mapped to white.

Big one here

Thanks to Rick Stevenson for pointing out the little planetary nebula at 6 o'clock. Entering the coordinates into Simbad, we find it is M1-41. The DSS image they show is a close match in morphology: the weird shape of the PN seems real.

Aspen CG16M with 3nM Astrodon filters on 20 inch PlaneWave. North up, field approximately 0.5 degrees wide, original image 0.55 sec arc/pixel. Moon 0-3 days.

Update:

We've now added a further 9 hrs of SII, and remapped to Hubble SHO. It was difficult to make it look "pretty" because the SII is relatively faint except where it is co-located with H-alpha. Thus the SII needs a lot of stretching, the stars get haloes, and the background gets gritty. But we think we've done a fair job of showing the SII given the difficulty.

We've tried hard to avoid the mortal sin of stretching the OIII and SII to make a pretty picture, and leaving the background a beautiful blue or purple when in fact there is nothing actually up there.

What we see: The SII shows fine shock front detail in the very bright areas, and in the planetary nebula. There also seem to be genuine diffuse clouds of SII far from the action, presumably stuff left over from long disrupted supernova explosions. Just guessing here.

Big one in SHO

Best,
MnT
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Last edited by Placidus; 18-08-2018 at 04:14 PM.
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