The Jellyfish Nebula

[Graeme]

The Jellyfish Nebula, IC443 in Gemini, a Supernova Remanent.

Captured 04/03/25. 90xL 25xRGB @ 4 minutes, 11 Hours total

An unprecedented week of clear nights allowed imaging sessions on five nights in a row! Three of those ended prematurely with only a couple of hours of photons captured before the 99% humidity ended the session for the night. My longest ever exposure but still quite a dim target. The bright star is Propus, Castor's left ankle.

IC443_EL.jpg

Higher Res

[HansV]

Great!

[ChrisGreaves]

Captured 04/03/25. 90xL 25xRGB @ 4 minutes, 11 Hours total

Another nice one, Graeme.
Let's see if I've got the hang of this:-
Your equipment is programmed to take several - hundreds? of - images of whatever it is you are trying to capture, and then, presumably after clearing some of the images - dropping images that have a satellite track - you stack them all together, much as I used to stack twenty-punched cards to check that all cards had the same result. (In my younger days I found it hard to believe that a computer could invert a matrix twenty times in a row and get the same answer every time.)

I read this morning that the number of detected moons of Saturn has - roughly - doubled, and Saturn now beats Jupiter in number-of-moons.
Also that Saturn is pretty well exhausted in terms of detecting small satellites by enhancing their illumination by stacking.

To a first-order of magnitude, are you doing what the Saturn team were doing - using stacking as an effective time-exposure?
Thanks, Chris

[stuck]

That's a really good photo, very impressive.



Ken

[Graeme]

Thanks Hans, Chris and Ken.

Yes, using stacking reduces noise. If you image a faint target in any sort of photography and use a long exposure to collect enough photons to produce an image then you would also capture long exposure noise. So if you take lots of shorter exposures the target is captured and the noise averages out giving a much better signal to noise ratio.

More detail here:

https://www.lifepixel.com/photo-tutoria ... le%20frame.