Artifact? Reflection? What is this in my IC2118 (Witch Head Nebula) Image? - Forums

Topic starter

Dec 5, 2023

I shot 265 60 second subs of the Witch Head and Rigel last night. I used my Rokinon 135 f/2 and ASI294MC Pro, with an Optolong L-Pro filter. All of the subs have a bright 'blob' not far from the center of the image, in the middle of the 'witch'. The first image below is a single stretched sub. The 2nd one is a stack of 90 subs with basic processing. The location of the blob was very constant through the whole session, but I do see a tiny amount of shifting around (just a few pixels) with respect to the nearby stars. After the meridian flip, the blob was still in the same spot with respect to the stars. Anyone have any idea what it is?

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andrea tasselli

Frequent contributor

Dec 5, 2023

There shouldn't be anything there. So either is an artifact or is a discovery.

Oscar H.

Dec 5, 2023

Might be a new faraway supernova; I don't think that was there before.

Oscar H.

Dec 5, 2023

For example, there is nothing like that in that area of the Witch shown in this top pick https://www.astrobin.com/5bfryz/B/?q=witch%20head&camera= from 19 days ago.

If anyone is interested, these are all the Witch Heads taken in the last month https://www.astrobin.com/search/?q=witch+head&d=i&subject=&telescope=&camera=&date_published_min=2023-11-05&date_published_max=2023-12-05&sort=.

David Fercho

Topic starter

Dec 6, 2023

Thanks - I really think it is an artifact, especially because I could see it move around a little bit as I blink through the subs. If it were a deep-space object I would expect it to maintain a constant position among the nearby stars. On the other hand, I think if were something in our solar system like an asteroid or object in earth orbit, it would move through the star field in a constant direction. It does not have the central brightness that I would expect of a supernova.

I am just really curious about what type of artifact would look like this one.

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Jens

Dec 6, 2023

The bright star next to the whichhead might cause lensflaring in your telescope. If you dither it should move around a little bit. but it does look weird, not very flare like.

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