Helix Nebula with POSS2 data

[gorann]

I have only managed to image half a night so far in 2017, mainly due to the weather,  so while waiting for clear skies (Thursday - Friday looks possible over here) I need to keep up and maybe improve my processing skills. So, I have had another go at some old POSS2 data.

POSS2 is a 1990ies sky survey based on monochrome glass plate images (red or blue filtered) taken with a 1.2-m Schmidt camera at the Mt. Palomar Observatory. Data is available at:
http://archive.stsci.edu/cgi-bin/dss_form

This is an RGB image made from POSS2 red and blue filter data with a synthetic green channel (a 50:50 mix of red and blue). All processed in PS CS5. Noise behaves a bit different in these glass plate images, and zooming in you see the silver grains of the photographic emulsion (at least I think that is what it is) before you see the pixels.

Comments and suggestions most welcome.

[wimvb]

Wow, you really are hoovering that database. Anyway, what comes out of the dustbag looks really nice. Lovely colour in this one. With this target I think you are being chased by the film grain, as you already noted.

Have you tried adding IR data to these images? I saw that the data is available from the repository.

I'm hoping to catch that gap in the clouds as well.

[gorann]

5 minutes ago, wimvb said:

Wow, you really are hoovering that database. Anyway, what comes out of the dustbag looks really nice. Lovely colour in this one. With this target I think you are being chased by the film grain, as you already noted.

Have you tried adding IR data to these images? I saw that the data is available from the repository.

I'm hoping to catch that gap in the clouds as well.

Hej Wim

yes let us hope for Thursday and Friday here in central Sweden!

I had a look at the IR data for one of the first POSS2 that I did and there was not much there, but I had not checked the Helix. If I add IR I could either do a false colour image (like NB) or add it to the red channel and either way it could be interesting. Have to keep it in my mind so thanks for reminding me. In any case, I now checked it for the Helix and there is not much more than bloated stars in the IR:

[wimvb]

I hadn't checked it either, just saw it was available in the repository. I wonder which type of targets are IR rich. Maybe time to delve into POSS.

[gorann]

5 minutes ago, wimvb said:

I hadn't checked it either, just saw it was available in the repository. I wonder which type of targets are IR rich. Maybe time to delve into POSS.

Do that!