Abnormal frame

Discussion in 'STX and STXL' started by Amedeo, Oct 21, 2019.

  1. Amedeo

    Amedeo Standard User

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    Hi everyone and Hi Doug ! My CCD is STXL 1102
    I have a problem with these frames and i dont' know what cause it.
    Each frame is 600 second long in Bin1 at -30
    I noticed that in the lower left corner there is a very obvious artifact and I don't know what it is due to. It is certainly not a nebular signal (or yes) ! It is present in all three frames R G B but in the relative flat field is not present !!!
    Can it be a frosting effect or what ???
     

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    Last edited: Oct 21, 2019
  2. Doug

    Doug Staff Member

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    My first guess would be a reflection from a star just outside the field.
     
  3. Amedeo

    Amedeo Standard User

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    So you exclude that it is a frosting problem ?
    Could it be caused by the light emitted by a Power Supply display at the base of the mount?
     
  4. Doug

    Doug Staff Member

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    It does not look like frost to me. That said frost can take on a lot of bizarre appearances.

    This will not be an external light source. It would be a bright star just outside the field reflecting off some internal surface in the optical train.
     
  5. Amedeo

    Amedeo Standard User

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    OK Thank Doug ;)
     
  6. Amedeo

    Amedeo Standard User

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    Maybe this star or is too far ?
     

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  7. Doug

    Doug Staff Member

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    That is pretty far off-axis, so if it is a reflection it would have to be something well in front of the camera.

    It could be something bright but not-that-bright that is closer to your frame. Look for something right on the edge.

    Next time you are at the telescope try imaging the field again. If you see a reflection try moving the telescope slightly.
     
  8. Amedeo

    Amedeo Standard User

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    OK I'll do it !
     

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