I searched my old data to save them on a separate hard disk and had to realize that I have lost 75 x 180 s excellent M31 data shot with the K3ii

But instead I found 1.5 hours of lights I obviously had forgotten and never processed. So here it is:



On Astrobin in full size:


The K3ii is a beast in terms of dynamic range and SNR. For only 1.5 hours of light it did a phantastic job.

I think there there is something special to see in the image. The lighter bow left of M32 is no artifact. I believe I have captured a tidal interaction stream between M32 and M31. I will search the internet for some references ( I found 2 but they are quite unspecific). BUT - as I learned M32 is an ARP object (#168, ARP = "Atlas of Peculiar Galaxies) with "diffuse counterarms" - if that is the correct translation...

Have a nice and sunny Sunday

Pete

What ISO was it shot at?

iso 800

Inspiring I have a lot of trouble to get more than an hour because I have to drive to a site and sleep in the car overnight and something always seems to go wrong. Oh to get even two hours on a target!

Spectacular Peter, the interaction between M32/M31 is quite easy to see on your B/W Flickr posts.
The Sunny Sunday has just reached the mid/western part of Jutland, we’re waiting for some higher temperatures

Wow, Very nice. What did you process this with?

Hi Keld,

today we are awaiting the first night where there is a first thin black bar in the Clear Outside diagram that indicates we reach astronomical darkness again (and that the sommer begins to end)

The b/w posts you cited are these:





I feel a little peculiar that this interactionis so clear in my image but can not be seen clearly in other (deeper exposed) images in the net. But as long as there is no proof that I am wrong I claim the tidal interaction is real

Cheers
Pete

I really love my little observatory site on the balcony i have built up overthe last years. I wonder if/how I can still use it when I have retired some day because in the direction where I take the images one residential area after the other is built up.

At least they spend more money and brain for a decent and effective street lighting - though they do not care for the astronomers, they do it for the bugs and the moths.

I used Astro Pixel Processor for the frame analysis, stacking, background calibration/neutralisation and a first stretch. Then starnet++ to generate a starless version for the stretching and PS CC for the processing and the combination starless/stars. The final tweaks were made in Lightroom Classic.

As you say, that feature near M32 does not seem to appear in the vast majority of images of M31/M32/M110 I have seen, including much deeper integrations at higher resolution, for example the famous mosaic by Rob Gendler (here). I would say, respectfully, that the burden of proof that it is real and not some sort of peculiar processing artifact lies with you.

Yeah, I have the same discussion on CN. I only can say that I dis not fake anything and that the "bow" is already visible in my old version of 2016 that wa made fro a bigger dataset (I lost a lot of frames):



I have snipped M32 from R. Gendler, inverted it and pasted it above my "bow". After a bit of a stretch Gendler's image only shows a very weak bulge at that place, not more.

I can offer for anyone who likes to download the untouched uncalibrated stack as a fits file from APP that shows the structure after a bit of stretching: Dropbox - St-avg-MWC_1_3.0_none-x_1.0_LZ3-NS-full-qua-add-sc_BWMV_nor-AAD-RL-MBB15_1stLNC_it3.fits - Simplify your life

And I do want to state that I did not fake anything (never!) and do not feel I have to prove something. I said already that I do not understand it myself and I am searching for images that show the same effect. I only found images that show less structure at that side of M32 but they show something:

The one that resembles most is this one:
Messier 31 [Image Of Team: Argentiero, Bottari, Donatiello, Favuzzi, Fusco, Ligustri, Milani, Pistocchini, Stone] (Giuseppe_Donatiello) - Full resolution | AstroBin

And then maybe this one (you have to click on the 8th image from the left):
Category:Messier 32 ? Wikimedia Commons

And a "plume":
Mantrapskies.com Astronomical Image Catalog: M032

I said "I would say, respectfully, that the burden of proof that it is real and not some sort of peculiar processing artifact lies with you." To which you responded "And I do want to state that I did not fake anything (never!) and do not feel I have to prove something."

I was responding to your previous statement, "But as long as there is no proof that I am wrong I claim the tidal interaction is real."

You brought up the idea of proof. You know full well that if you see or detect or measure something (most) others don't, then such a claim requires corroborating evidence to be taken seriously. As a permanent feature that you detected rather easily, solid confirmation of a tidal loop should not be difficult to find. But the evidence seems as tenuous as the loop. No other photos of it show it anywhere near as prominently as yours.

To be clear, if you have actually imaged something real in a much better way than in previous images then it would be valuable to know exactly what part or parts of your process enabled that. There could be something here much more important than just a really nice photo!

Obviously my uncertainty with the english wording has trapped me once more. I meant it weaker, maybe like to believe strong. I take that word back because I don't use to "claim" anything without beeing able to make a proof. But I invite you and anybody else to download that fits file above and look what you can find there. I can also provide a 32bit tiff or whatever, even the original Pentax DNGs.

Though I was able to stretch the data very far I do not think the structure in question is a result of special processing steps/skills because it is also visible in the old photo but much more faint. In 2016 my processing skills were on a much lower level.

What I'll certainly do is spend some camera hours on M32 in RGB as soon as it high enough in the skies here in a clear night.

How did you get APP to recognize the RAW frames? It doesn't yet support DNG or Pentax PEF files. I converted some images to FITS in Nebulosity 4, but I lost all the color data in the process.

I export the DNGs to 16bit Tif files from Lightroom to import them into APP. The files get quite big but it works fine. Sometimes I have the feeling the colors are shifted but this is healed in the APP calibration later in the process.

Another idea would be to split the DNG/TIF/PEF into b/w RGB channels in Nebulosity, export as fits, stack separately and recombine in APP but do not have Nebulosity and do not know if that works.