Helix quad narrowband teaser

[Slawomir (Suavi)]

Hi all,

Today I started tidying up about 190 hours worth of Helix data and created 4 drizzled narrowband masters. SII, as expected, is very weak in spite of a significant integration - if anything, SII may be useful for making star masks.

Adding other channels to Ha enhances SNR in the brighter regions, but the outer bows weaken, so I may use straight Ha for Luminance.

NII, OIII will be used for colour, and will see if SII will be useful. I may also try blending Ha and NII into one colour channel, possibly red.

[Placidus (Mike and Trish)]

An awesome project, Suavi.

Could I suggest combining NII and SII into a single channel? The logic is that they both represent stuff from deep within the star, and have approximately the same astrophysical meaning, quite distinct from the H-alpha and OIII ?

Best,
Mike

[codemonkey (Lee)]

[ChrisV (Chris)]

Like wow! An excellent project outcome

[strongmanmike (Michael)]

F me dead! it's all great but look at that OIII!!! the spokes have been revealed nicely plenty of times before but don't think I have ever seen it curve over so distinctly like that, like a wave crest! awesome.

Now, the hard bit....combining it all

I agree with M&T on the SII/NII

I think if you can get the colour combine right...you may well have created the truly ultimate Helix image ever! A Rolf Olsen Helix if you will

Mike

[Slawomir (Suavi)]

Thank you for encouragement everyone, and for the suggestion of merging NII and SII together Mike & Trish and Mike.

Nearly finished the Lum and quite happy with the result. The rest of the data will need to wait, because the ocean is flat at the moment so it's time to take the tinny out for a spin

[Andy01 (Andy)]

Holy Helix Batman - 101 hrs of HA? That's an extraordinary achievement in itself - and backed up with the other data? - you'll be able to sell tickets to view this one when it's finished!

[Slawomir (Suavi)]

Ha ha, thank you Andy. I just kept going, perhaps delaying the inevitable point in time when I have to put all that data together

Actually, now I have 197 hours and 10 minutes of HA+OIII+NII+SII. Some of that time could have been distributed better between the channels, but it is what it is.

Looking at HA, in the long bows the signal from 5 previews in the first image is on average at 41.33 ADU. Background ADU is at 39.73 ADU. So the signal in this bow is at 1.6 ADUs, perhaps less further away from the Helix.

With my camera's gain at 0.27e/ADU, which equals to 3.7 ADU per registered photon, and 15-minute exposures + 20-minute exposures, the scope-camera recorded about 1.5 photons per hour of exposure in those bows.

BTW, background st.dev in all masters is at 1 ADU (0.27e) and it does not want to go any lower. Maybe this is a result of the skyglow or background DSO signal and it will never really go below 1 ADU?

[Atmos (Colin)]

Wowsa Suavi!
This is truly an epic achievement! Echoing the sentiments of others, this is likely to be the best amateur Helix to date. Throw it out there for an APOD

[Paul Haese]

You have gone past my effort of 111 hours on the Helix. Many thought I was nuts when I did that. I thought that would never been breached. Well records are always meant to be broken. I look forward to your image, it is going to be epic I reckon.