M51 Deep Field.

[ollypenrice]

RASA capture and pre-processing is, as usual, by Paul Kummer. TEC capture and all post processing is my fault!

The RASA can't do high res detail with a 400mm FL but in 9 hours it can go seriously deep. This image is mostly RASA with the spiral details in M51 coming from a TEC 140 image at 0.9"PP. The RASA image was up-sampled by 25% and that's how you'll see it if you go to the full res. I think it's remarkable that we can get away with this when chasing faint tidal loops but, of course, they contain no small scale detail.

Noise Xterminator is a big player in this trick.

Full version is here: https://ollypenrice.smugmug.com/Other/Galaxies/i-HVknc9M/A

Olly

[DaveS]

Crikey, that's DEEP! Tidal structures i've never seen before.

[Clarkey]

Very nice. The RASA's seem to be showing more and more 'new' stuff.

I had just finished processing an M51 using Roboscopes data. 8 hours with a 12" dobsonian. I was quite pleased with the tidal tails on mine. Then you posted this.......😧

 

[callisto]

Wowser... stunning 😮 

 

Mark.

[ollypenrice]

1 hour ago, Clarkey said:

Very nice. The RASA's seem to be showing more and more 'new' stuff.

I had just finished processing an M51 using Roboscopes data. 8 hours with a 12" dobsonian. I was quite pleased with the tidal tails on mine. Then you posted this.......😧

 

What was your image scale with the 12 inch? I'm just wondering if you were oversampled, in which case resampling downwards before processing might be good for the faint stuff.

I also wonder if it might be possible to downsample still more, stretch the hell out of the tidal streams, denoiose them and then resample them back up again to blend with a conventionally processed main spiral.

Thinking out loud.

Olly

[bottletopburly]

Stunning image olly great work 👍

[rl]

Quote

One thing's for sure: I would not try to sell any image which did not contain something new, something not seen in any existing images. Over the last fifteen years that might leave me with about five images which meet this requirement, so not many!

Better make that 6!

Brilliant work...

[Clarkey]

1 hour ago, ollypenrice said:

I'm just wondering if you were oversampled

Definitely. Native is 0.73 arcsecs/px. I normally bin2 but I might push this to 3 or 4 and see what it gives me. Worth a try.

[WolfieGlos]

Holy moly, that's an incredible image of M51 and the tidal stream you have there Olly. Well done 👏

In fact, you've got nearly as much of the stream as the 250 hour collaboration that team did (last year?), although I think they had a lot of Ha exposure in that time. I wonder what 250 hours of RASA imaging would reveal ........ 😉

[ollypenrice]

I was intrigued, this morning, by the feature looking like a tidal tail emerging from NGC5198, the elliptical to the right of  M51. First I wanted to check that it wasn't an artifact and a careful look at the data, equalized in Ps, suggested it wasn't. I then found a couple of comparable images, including a good one by Dave Wills of PixelSkies, which also show it. Dave describes it as 'recently discovered,' as do a few other imagers who've captured it. I haven't yet found anything about the discovery but will keep looking.

Yet again, the RASA shows us that 'deep is fun.'

Olly

 

[gorann]

Amazingly deep image and a great idea to point the RASA towards M51 & Co. I wonder if it would be worth while for me to point my RASAs at the same area with IDAS NBZ (Ha+Oiii) filter on? The moon is up but the NBZ still makes imaging possible.

[ollypenrice]

32 minutes ago, gorann said:

Amazingly deep image and a great idea to point the RASA towards M51 & Co. I wonder if it would be worth while for me to point my RASAs at the same area with IDAS NBZ (Ha+Oiii) filter on? The moon is up but the NBZ still makes imaging possible.

The 255 hour image on AB does show some field Ha which you might pick up. Probably worth a look, though they said it was very faint.

Olly

[DaveS]

I need to stop looking at the RASA 14.

[tomato]

Yet another field where the RASA’s abilities can be utilised!👍

Its not in the same location, but does the structure in the top RH corner fit with @BrendanC’s image posted recently?

I was imaging M51 with a RASA8 and an ASI678 last night but it was more to emulate how the Celestron Origin might perform rather than going really deep. Still, about 4 hrs is a start…

[wimvb]

1 hour ago, ollypenrice said:

The 255 hour image on AB does show some field Ha which you might pick up. Probably worth a look, though they said it was very faint.

Olly

Amazingly deep image, Olly. On my screen I definitely see a faint red background towards the right. (But also a very blue star, so can it be colour saturation?)

[ollypenrice]

15 minutes ago, wimvb said:

Amazingly deep image, Olly. On my screen I definitely see a faint red background towards the right. (But also a very blue star, so can it be colour saturation?)

In the end I decided it was in the data, though this may be wrong. It's been through DBE. There is certainly what looks like IFN in the top right.  I do think the small star count might be lower in the redder regions, suggesting the presence of obscuring dust. I think when the capture is very deep it's reasonable to expect variation in the background but it's very hard to tell.

I can see absolutely no trace of the green glow seen in BrendanC's image in an Equalized version of our data and have to conclude that it must be spurious.

Olly

 

[wimvb]

1 hour ago, ollypenrice said:

There is certainly what looks like IFN in the top right.

Yes, It shows better in the image you posted on AstroBin, as does the red in the background.

[ollypenrice]

1 hour ago, wimvb said:

Yes, It shows better in the image you posted on AstroBin, as does the red in the background.

Well spotted. The difference is just half a point in Ps Colour balance, midtones, away from green towards magenta. That's one point, faded by 50%.

Because I wasn't confident about the background reds I reduced their colour saturation early on.

Olly

Edited April 14 by ollypenrice
typo

[wimvb]

1 hour ago, ollypenrice said:

Well spotted.

Courtesy of my computer screen. It shows even the smallest irregularities even when my Galaxy Tab just shows pitch black.