The Heart Nebula in HaR_OiiiG_OiiiB

[Laurin Dave]

The Heart Nebula in HaR_OiiiG_OiiiB. Imaged through my Esprit 150/SX-46 with piggybacked Esprit 100/ASI1600mm on a Mesu 200 from late September to mid November. Ha and RGB through the 150 and Ha and Oiii through the 100. This is a four panel mosaic totalling 52hours Ha, 16hrs Oiii and 16hrs RGB, I'd like to have got more RGB and Oiii and added Sii but progress has been clouded out for the last few weeks and I feel the need to move on to new targets. Processed in Pixinsight and Photoshop with use made of the StarNet++ module in Pixinsight

The Heart Nebula, IC 1805, Sharpless 2-190, lies some 7500 light years away from Earth and is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. It is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes.

The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered. The nebula's intense red output and its morphology are driven by the radiation emanating from a small group of stars near the nebula's center. This open cluster of stars, known as Melotte 15, contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun's mass.

Thanks for looking

 

Dave

 

 

[vlaiv]

Very nice image.

In fact only "objection" that I have is that usage of starnet is a bit obvious. I concluded that you've used it without really reading it in your image description. There is something about star - nebula transition that makes it too "hard", but this can only be seen in close scrutiny.

 

[vlaiv]

I hope you don't mind me posting this analysis - I just wondered what is it that makes stars stand out like that. Not something that I can easily quantify with words.

It turns out that you have slight "terrace" in your star profile in some channels that eye/brain is not used to (we usually see and expect smooth profile - smooth transition from star to background - much like gaussian shape), but in your image above, this is what happens:

Green channel:

Blue channel:

Red is for most part and does not suffer this:

Trick would be when processing stars separately to make transition smoother and more gaussian like without this terrace effect.

[Laurin Dave]

Thanks Vlaiv…  with the Ha I blended Starless and Starry at 50:50 but didn't with the Oiii..  so maybe that's why.. 

Dave

[gorann]

Great image Dave, well worth the outstanding effort. I did notice that the stars were maybe unusually sharp but did not mind, even liked them, but then I am just an ordinary pixel peeper, not such as scientific pixel peeper as Vlad, but he may have a point. Excellent nevertheless!

[Ceph]

For my eyes that is a lovely image :)

[alan potts]

That is very nice indeed Dave, I had a go on a getting worse sort of a night a few days back and sadly only got the middle bit and was rather disappointed. The scope is a bit too heavy for me move at the moment ( I can easily pick it up with one hand but shouldn't) I want to get the Borg mounted up and have a play with wide field, at least I am sure the Heart will fit. Didn't have much luck with the soul either, took a lovely image with the camera 90 degrees out, would just fit if correct.

Alan

[Rodd]

Wow--I love red hearts!  the more I see the Heart nebula the more I appreciate the broadband palette--which this is even though there is narrow band data mixed in.  I think the stars look good--the big ones are a bit......fuzzy, but the more I look the halos do not get worse.  The medium to small stars look perfect.  Where I noticed the star thing is the double star neat Melotte 15--the benchmark for good focus/guiding/resolution for this target.  You have separation....sort of. The companion is up against the fuzzy halo of the primary, but it is still visible.  Other than the big stars (which i can easily live with because its only visible when one is pixel peeping which is not the normal viewing) I think the image is great.

Rodd

[Laurin Dave]

 

19 hours ago, Rodd said:

Wow--I love red hearts!  the more I see the Heart nebula the more I appreciate the broadband palette--which this is even though there is narrow band data mixed in.  I think the stars look good--the big ones are a bit......fuzzy, but the more I look the halos do not get worse.  The medium to small stars look perfect.  Where I noticed the star thing is the double star neat Melotte 15--the benchmark for good focus/guiding/resolution for this target.  You have separation....sort of. The companion is up against the fuzzy halo of the primary, but it is still visible.  Other than the big stars (which i can easily live with because its only visible when one is pixel peeping which is not the normal viewing) I think the image is great.

Rodd

Thanks Rodd..  needs more and better data really (especially RGB).. to sort those fuzzy stars out.  Owing to persisitent cloud I've only managed an hour per channel RGB in each of the four panes so far and the reds were taken low down hence the issue I guess..  

Dave

 

[Rodd]

2 minutes ago, Laurin Dave said:

Owing to persisitent cloud I've only managed an hour per channel RGB in each of the four panes so far and the reds were taken low down hence the issue I guess..  

With the weather I have been experiencing a mosaic would take years!  literally--If I had horizon to horizon viewing it might be different, but alas, trees can be ornery beings at times.

Rodd

[Adam J]

On 18/11/2019 at 21:37, vlaiv said:

Very nice image.

In fact only "objection" that I have is that usage of starnet is a bit obvious. I concluded that you've used it without really reading it in your image description. There is something about star - nebula transition that makes it too "hard", but this can only be seen in close scrutiny.

 

Its easy to fix just make a star mask expand by a couple of pixels and then do a 0.5 pix Gausian blur to soften the transition. 

[tomato]

Wow! Some real dedication on this one, and you have been rewarded with the final image, superb.👍