gorann

On 02/06/2024 at 10:01, tomato said:

Interesting discussion. I’m considering a middle option, in a few years time, trading the dual refractor rig in for a large aperture RC but keeping it in the UK, hopefully to a decent dark site when we make our final house move. 
 The trouble is the way I fear the UK climate is going it would just gather dust rather than photons.

I am going in the opposite direction, having taken down my 14" Meade ACF and will set up a dual Esprit 150 rig when astrodarkness returns. Even if I have a dark sky, I have realized that seeing here is almost never good enough for allowing the 14" to resolve more detail than a 6" refractor.

10 hours ago, wimvb said:

Today on astrobin:

https://www.astrobin.com/nxatl6/?nc=all

Amazing image, but then it is 66 hours of data. Like for @ollypenrice a RASA 14" is more desirable for me than a Planewave 17 CDK, and the RASA is about half the price (18 000 compared to 30 000 Euro)! Surprisingly, I see a lot of amateur images taken with Planewaves but almost none with a RASA 14".

12 hours ago, wimvb said:

Fixed it.

https://www.astrobin.com/ba76rq/E/

I must admit, part of that galaxy is as faint as the tidal tail in ngc 3921 (extending downwards in my orientation of the fov)

I retract my "dot" comment after now having seen your image Wim on a proper computer screen (and not my phone). It actually looks a bit deeper than mine but then you had more than four times more integration time. What is most striking is that your scope, camera and mount cannot have costed more than a few percent of what the set-up in Spain costed, and then you do not need to pay a rent for your backyard pier.

Thanks Wim! Yes That dot is one of them🤣

Here is an image that appears to contain more galaxies than stars. The most peculiar object is Arp 224 (= NGC 3921). In the catalogue given out Dr. Halton C. Arp between 1961 and 1966, named the Atlas of Peculiar Galaxies, Arp 224 was  classified it as a "galaxy with amorphous spiral arms". The odd shape of this object could be the result of two merging galaxies. It is located 280 million light years away in Ursa Major. There are very few images of Arp 224 on Astrobin.

The galaxy near the bottom of the image is NGC 3913, a 12.8 magnitude spiral galaxy some 46 million light years from us. It looks like this is an Astrobin debut object as I have not found any other images of it (except as a small dot in a few wide field images).

In Gary Imm's description of his image of this area (https://www.astrobin.com/medktn/) he pointed out that the orange elliptical just below Arp 224 is PGC 2491113, the brightest galaxy in a cluster of galaxies known as Zwicky Cluster 1148.6+5523, one billion light years away.

I took this image with the Margareta Westlund Telescope in southern Spain, owned by the Swedish Amateur Astronomical Society and accessible remotely to its members. It is a 17" Planewave CDK with an ASI6200MM. This is an LRGB image with just over 3 hours integration time. I wish I could have got more but there were some initial computer trouble and then nights are getting short also in Spain. Processed in PI and PS including the XTerminator tools of course.

Cheers, Göran

On 21/05/2024 at 14:03, Herbert West said:

This is fantastic and underappreciated work! I'm in the long process of imaging IsWe 1 with f/5.26 scope and mono camera. I know how faint that is.

Furthermore, this is the first and only image (to my knowledge) that unambiguously shows its surroundings. I see some very faint traces of that in my Ha data but I wasn't sure if that's just noise.

Again- respect!

Thanks a lot for your kind words Herbert! Great that my image may be of help to you.

Cheers, Göran

I am impressed what you have managed to achieve under these conditions! What procedure did you use to get rid of the gradients?

7 hours ago, skyhog said:

incredible stuff Göran. 

I have to say, modern imaging can actually make very familiar objects look anything but at first glance.  

Thanks and I agree

Cs Göran 

11 minutes ago, tomato said:

You’ll never image alone…

He he. If you want to have a go at the M57 data I now added the stacked files to the post.

Back in 2017 I discovered the free data treasure of the Liverpool Telescope, a 2 meter reflector in the Canary Islands (https://telescope.livjm.ac.uk/). The data was (and probably still is) freely available on their site although rather unsorted so half the job was finding subs spread out over time in their data base.

Now 7 years later I decided to have a go at reprocessing some of the images (using the data I downloaded in 2017) and subjecting them to the new XTerminator tools.

Here is my first reprocess, and the stacked files for anyone that wants to have a go at it.

Cheers, Göran

My 2017 version:

My 2024 version:

The stacked files (HaRGB):

LT M57 G.tif LT M57 B.tif LT M57 Ha.tif

LT M57 R.tif

3 hours ago, ollypenrice said:

Thanks, Goran. I never think to use SCNR green on non-linear images but your suggestion worked perfectly. It gave me complete control over the green-blue balance, so here it is more towards blue. I could have taken it further but I'm a believer in baby steps!

Olly

Perfect! Glad to be able to help the master!

Göran

10 hours ago, ollypenrice said:

It is pretty green, I agree. I blended the OIII into blue and, in a separate image, into green then weighted them in Ps layers. I would like to have given the blue a little more weight but this dramatically lowered the visibility of the outer shell and the temptation to feature it was too strong!

Olly

Why not just try an SCNRgreen and see what happens?

54 minutes ago, ollypenrice said:

I continue to think that Photoshop is usually easier to control than anything else. I add Ha to red using blend mode lighten, though you can also use blend mode screen if you bring in the black point, I've read. I need to try this.

I no longer give any thought to the stars in stretching because I'm going to remove them anyway and replace them with stars of an entirely different stretch. I also remove NB stars now, when adding Ha or OIII to the colour channels. That way they have no effect at all on the RGB stars.

Olly

Yes, an outstanding image in every way with all those Ha structures nicely brought out!

By the way I learnt yet another way of adding Ha (a Youtube video but forgot which one). First I process the Ha image until I am pleased with it. Then (in RGB mode in PS) I move the slider in Color Balance so that the Ha image becomes purely red. Then I add it to the processed RGB image as a layer in blend mode lighten and can play with curves and transparency (and the brush tool) until I like what I see. So far I have only tried it on galaxies so I am not sure how well it works on an image like this.

Göran

From both out images I conclude that the more detail you bring out the less it looks like an owl🤫

23 hours ago, ollypenrice said:

Beautiful, Goran. Lovely fine detail in the main nebula along with fine outer region.

Olly

Thanks a lot Olly! I was surprised how much detail that 17" CDK could gather in just 3.5 hours. Nights are getting short also in southern Spain, and even shorter when the computer down there did not want to collaborate for the first hours.

That looks really good Olly, with nice structure also in the outer halo. But maybe a bit green?

1 hour ago, Hals said:

Excellent image Goran. So much extra detail over what one usually sees, like a whole new M97. Yes, I do like this one.

Thanks a lot Hals! Yes, I was thrilled to see all the detail this 17" scope could catch, and I think I was lucky with the sky in Spain last night.

23 minutes ago, glafnazur said:

That's really nice. Lovely colours and detail.

Thx a lot, much appreciated!

The Owl Nebula, a planetary nebula situated about 2000 light years away in Ursa Major, is a quite bright PN and therefore often imaged. I picked it as last nights target for the Margareta Westlund Telescope in Spain since the moon is out and it is a great Ha and Oiii object. This is a mix of data. I collected the detailed Ha and Oiii data during 3.5 h with the Planewave 17 CDK (the "Margareta Westlund Telescope"),  and mixed this with IDAS NBZ data collected with my dual RASA-8 rig in Sweden. The latter contributed especially to the star color and the dusty and often missed outer ring. I am quite pleased with the details picked up with the 17" scope.

Totally about 13 hours of data processed in PI and PS with the XTerminator tools. Cameras were ASI6200MM (with Chroma 3nm Oiii and Baader 3.5 nm Ha filters) for the Planewave and ASI2600MC for the RASAs.

Cheers, Göran

On 15/05/2024 at 09:30, WolfieGlos said:

That's certainly a unique image! Stars look pretty decent too. Although if you hadn't said Aurora, I would have assumed that he'd captured a lot of Ha 😆 Is there any near M13?

That's a shame goran. At 60 degrees, do you often get affected by nights with the Aurora in the darker months?

Actually I have not seen Aurora up here at 60°N for many years. We see it as a northern Sweden phenomenon (around 70°N) and nothing to be expected here in the southern half. So clearly this has been a once in a lifetime event with unprecedented sun activity. I am surprised that we have not heard more about disturbances of electronic infrastructure.

I guess you can do like Lorand Fenyes and make a memorable image of what M13 looks like during full Aurora:

https://www.astrobin.com/tcyv9y/

Up here at 60°N the sky was in any case too bright for imaging and even too bright for seeing any Aurora.

I had a look around midnight but up here at 60°N the night sky is just too bright for any aurora to be seen. A bit odd that aurora right now is best seen further south.

1 hour ago, ollypenrice said:

Splendid tidal streamers. Arp was an interesting character who shared Hubble's doubts about the redshift-as-distance interpretation and was in search of 'new physics' to offer an explanation. Neither of them found any but, as Feynman said, 'Science is a culture of doubt.' So far, I don't think he has been studied by a biographer but he deserves to be.

Olly

Thanks Olly! I think I read somewhere that Arp had the odd thought that the galactic interactions were more about repulsion than gravitational attraction.

17 hours ago, WolfieGlos said:

That's some serious kit, you certainly are lucky to have access to something like that Goran! As if a dual Rasa rig isn't enough....

Superb image too, by the way! 😄 So many small fuzzies around the field, with some minute detail in them too. And of course the tidal streams. The one between the two PGC's to the right of NGC3690 is particularly striking. Is that a faint stream running from IC694 down to the bottom-right?

Thanks and Yes, that kit prolongs my season since my RASAs are resting until late August due to the bright summer up here. Yes, there is a faint tidal stream running downwards. Maybe a the remains of where the galaxies have drifted after they first collided?

Amazing! Gary Imm at 30.8 °N in Texas just posted this on Astrobin:

https://www.astrobin.com/0fyj7z/