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Planet X: Mar 6 Nebula Ghost?

It appears from correspondence with the scope owner that someone took an
image of M42 prior to the Mar 6 single image taken. How convenient for

     Arnie said the following to me using Yahoo Messenger.

          arnierosner(9:51:21 PM [EST 3/7/2003]: It looks like there was some residual
             charge left in the camera previous to your first image. The Orion Nebula is
             clearly embedded in the background.
          arnierosner: OK. I seem to remember another client taking a 120 second image
             of m42. It was probably before your image and it left a latent image on the
             chip because it was so saturated.
          arnierosner: I just don't remember what days this occured or the sequence of

               From: John P. Oliver
               Sent: Friday, March 07, 2003 1:01 PM
               Subject: Hoax or Mistake?

               Arnie: I assume that the image take by Naji posted at
      was taken with
               one of your scopes. As presented it is clearly a superposition
               of an image of the Orion nebula M42/43 onto a different star
               field. Could you look at your logs and see if by chance the same
               scope imaged M42 immediately before Naji did his image and it
               left a ghost?

               John Oliver

What I, Nancy, am not understanding is why the nebula came through as a
ghost, but the intense STARS in the center of the nebula did not!  Are
they not more intense than the nebula?

From the technical description of how a ghost works, would not the STARS
transfer more readily than the nebula itself?  Yet they are missing.

    If the cloud was there, it should have showed up on the
    images that I took the next night [Mar 7] as well.

    The CCD controller can give a "short circuit" signal or as
    they call it a reset signal to erase CCD contents. It's more like a
    capacitor discharge. This “short circuit” is based on transistors,
    which have resistance. It’s more like a resistor than a short
    circuit wire. It takes time to discharge. The default timing is
    enough for most applications. It must be a controller malfunction,
    and/or the user before me took a really very long bright exposure.
    I think it’s the first, a controller malfunctioned and didn’t apply
    reset as it should be or didn’t apply a long enough rest signal,
    or the reset signal was not received correctly by the CCD (most
    likely cause). Electric noise can affect controller’s signals, and
    thus misinterpreted by the CCD electronics.

    One way to avoid this is by taking a short dummy image and
    through it. This does not happen very often.