Pacman, dust, a horse, and near gale force gusts

[Fegato]

I'd imaged NGC281, aka the Pacman Nebula, with a dual narrowband filter a couple of times in past years, but was prompted to add it to my list of broadband targets this autumn after spotting an image showing plenty of dust around a few weeks back (which I can't credit because I can't find it now, sorry). @cfinn beat me to it, with his excellent image posted a few days ago, but I've managed to get mine done now and here it is.

I captured the data on Saturday. It was a rare clear night, but the wind from one of the weekend storms was strong - 20mph with gusts over 35mph. A bit foolhardy to try and image in those conditions...   but sometimes beggars can't be choosers, so I risked it. I sat on the target for much longer than I normally would as I knew lots of subs would be wasted. Guiding was often at 2" RMS, and I had plenty of in-sub dithering! Anyway, the rig stayed upright, and with 30 second exposures, I managed to get just over 1 in 3 that were usable.

Processing was a bit of a battle, mainly due to me stretching so hard to really push the dust (maybe I've pushed too far?). Firstly trying to control the brightness of the Pacman while bringing out the dust was tricky - in the end, despite a lot of masking, I resorted to applying PI's HDRMultiscaleTransform on the nebula, which worked quite well. And secondly I had a lot of colour balance issues. Red channel seemed very weak after stretching, even after careful background neutralisation and colour calibration, so I had to push it a bit. Not sure if my dust hasn't ended up a bit orange. 

I was interested to spot the little areas of reflection nebulosity and perhaps star forming areas above the Pacman in this image. One of the reflection areas is catalogued as DG6. I found an image on Astrobin of DG6 which pointed out that the area of dust around it looked a bit like a horse (lots of horses up there it seems!). This image is over 10 years old, and rather nice I think - bright colourful stars shimmering with just a faint ghostly horse visible in the background  https://astrob.in/60471/0/.  I attach a crop of my horse too - a bit puffy and unsubtle in comparison. Possibly this star removal business encourages us to go too far sometimes...

Anyway - captured with RASA 11 v2 on CEM120, ASI2400MC Pro, 120 x 30s (out of 302 attempted)

[WolfieGlos]

Personally, I see more the head of a hound than a horse!

Fair play for imaging in those winds on Saturday, I decided against it due to the high winds...the monster of a hangover from a works xmas party had nothing to do with it... 😒

Stunning image, we really are being treated to some nice dusty Pacmans lately. Possibly pushed too far, but only if you zoom in .... and I wouldn't change it personally. Perhaps just add more data in due course?

[cfinn]

This is great! Nice that you have a wider field than me to capture more of the dust. Having a RASA must really help with pulling it out too. I only captured a small portion of DG6, so it's really interesting to see it in its entirety here.

Like you, I had to stretch the data much more than I would like to get the dust to have a strong enough presence in the image. This really blows out the nebula, so I also had employ HDRMT, but I think it is an extremely powerful and elegant technique that becomes mandatory for this kind of presentation.

CS

Charles

[Fegato]

5 hours ago, WolfieGlos said:

Personally, I see more the head of a hound than a horse!

Fair play for imaging in those winds on Saturday, I decided against it due to the high winds...the monster of a hangover from a works xmas party had nothing to do with it... 😒

Stunning image, we really are being treated to some nice dusty Pacmans lately. Possibly pushed too far, but only if you zoom in .... and I wouldn't change it personally. Perhaps just add more data in due course?

 thanks Chris! Yes, I could try adding some more, but I normally think an hour with the RASA is enough when shooting broadband, not least because I'm always impatient to move onto other targets!

[Fegato]

1 hour ago, cfinn said:

This is great! Nice that you have a wider field than me to capture more of the dust. Having a RASA must really help with pulling it out too. I only captured a small portion of DG6, so it's really interesting to see it in its entirety here.

Like you, I had to stretch the data much more than I would like to get the dust to have a strong enough presence in the image. This really blows out the nebula, so I also had employ HDRMT, but I think it is an extremely powerful and elegant technique that becomes mandatory for this kind of presentation.

CS

Charles

thanks Charles!

Yes HDRMT is a nice tool to have available and does usually do a good job, just a case of getting the balance right with the layers (bit subjective I guess, but I don't like it when it makes things too "flat")