Strange artifacts in picture of IC405 - Forums

Topic starter

Dec 3, 2023

Hi,

I acquired 1 h 55 m by 23 exp of 5 min each of IC405. Telescope was Takahashi FSQ-106 and camera was ASI2600MC Pro.
During processing a strange form, like an arc with dark streaks from left to right in that area. I can't figure out why they are there. Can anyone explain to me what is wrong? Is it in processing, in camera, in telescope or something outside the equipment?

I have compared my picture with many of the other IC405 here on Astrobin but as far I can see no one else seem to have that problem.

Please help me if you can.

andrea tasselli

Frequent contributor

Dec 3, 2023

Off-field bright star. Plenty there.

Göran Nilsson

IOTD Staff

Dec 4, 2023

Yes, I also think it is a bright star outside your field of view that is causing reflections in your imaging train.
Bästa hälsningar, Göran

Well Written

Davide Manca

Dec 4, 2023 · Edited: Dec 4, 2023

Agree with the bright star, it should even be possible to understand which was the star…lok at the orientation of the picture and see which star is in that direction.
You could try exposing new frames but with a different rotation of the camera
My guess is HIP 24575

Jared Willson

Dec 5, 2023

I agree with the others who described the likely cause. I have run into this issue before with my system as well. The only solution I have ever found is to take a second set of exposures composed differently so that the reflections are either absent or in a different location, then substitute some data from the second set of exposures for data from the first set using pixel math and a mask. Works great, but requires an entire second set of data. The only other solution I can think of is to see if you have the same issue in all channels. If not, you might be able to substitute, for example, some green data for your red just in the area of the arc, again using pixel math and a mask. You'd have to do some sort of linear fit, but that shouldn't be too hard. This avoids the need for a second set of data but will only work if the reflection is visible only in a single channel.

- Jared

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