Interesting object

I am intrigued by the many irregular, meandering, linear shapes that appear green, blue, red just like this.
but it will be a failure of the lens…?

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Generally these “artefacts” tend to be one of two things:

  1. Cosmic rays - when a a highly charged particle hits the detector, it knocks some electrons loose and causes a line like this in the image. Cosmic ray artefacts tend to be shorter and not very straight. This is quite a long cosmic ray (I think it is a cosmic ray at least).

  2. Satellite trails - when a satellite passes through the detector’s field during a capture, the detector captures the satellite’s movement. They tend to be fairly long and straight. I have linked an example here . That page has other artefacts but the satellite trail is 2nd down on the right.

Other artefacts linked here

Hope that helps :slight_smile:

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I found a lot of reason in your comment in the examples of satellite trails, I agree since I have seen many cases of these where these projections are linear, such as star brightness or the aforementioned.
But my question is. can a cosmic ray be so irregular, if this would be the case it would look like this?

I suspect the curlyness of the artifact depends on the energy of the particle that hit the ccd.

This example is definitely a cosmic ray, maybe a muon. It’s hitting the CCD and knocking off electrons as it goes, sometimes bouncing and changing direction until it loses all its energy.
Other kinds (alpha particles?) leave small-area but very bright signatures because they plow to a halt and dump all their energy in a few pixels.


found a weird circular one earlier - no clue what would cause that though

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