Thors Helmet NGC2359. Different, WITH SII, 51 hrs.

[Stevec35 (Steve)]

Wow - like that a lot Fred and the SII really adds to the result.

Cheers

Steve

[Placidus (Mike and Trish)]

Fred, your depth of SII is spectacular. Our shot is in NII, not SII.

I've tried hard to get a handle on where you'd see the one and not the other. Both are forbidden transitions, meaning they are only seen in extremely attenuated gas. Both require hard UV (or, perhaps and not relevant here, shock energy) to excite them, so they both need OB stars around. But nitrogen is produced earlier in nucleosynthesis than sulfur, so there might be more NII around in the absence of supernovas to dredge up really deep stuff. Having said that, the similarity between your SII and our NII distribution is very, very close. Almost exact. I think that's reassuring for both of us.

Superb result, Fred.

Best,
Mike and Trish

[Bassnut (Fred)]

Originally Posted by Placidus

Fred, your depth of SII is spectacular. Our shot is in NII, not SII.

I've tried hard to get a handle on where you'd see the one and not the other. Both are forbidden transitions, meaning they are only seen in extremely attenuated gas. Both require hard UV (or, perhaps and not relevant here, shock energy) to excite them, so they both need OB stars around. But nitrogen is produced earlier in nucleosynthesis than sulfur, so there might be more NII around in the absence of supernovas to dredge up really deep stuff. Having said that, the similarity between your SII and our NII distribution is very, very close. Almost exact. I think that's reassuring for both of us.

Superb result, Fred.

Best,
Mike and Trish

Thanks Mike n Trish.
Makes me wonder then that I should always look for NII whenever I cant find SII , just in case,as a substitute.

Did you find NII brighter than SII on Thor?.

[Paul Haese]

The detail Fred kicks butt as you stated on my little FSQ version. I sort of like the version with the green which could be moderated a little I think, but again this is all dealers choice. I am not keen on a purple cast to this target though. You still have lots of choices though I think. The original is still a nice image.

[gvanhau (Geert)]

I like the colors.

[CoolhandJo (Paul)]

Very nice Fred.