Is there an asteroid in this set?
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Foundren_Shi
The movement of the spot in the picture dosen't follow a straight line but in a more irregular pattern. Woule it be an asteroid?
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Turkwise
No, that is an artifact. I don't know why, but a lot of artifacts follow that exact pattern.
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scibuff
in response to Turkwise's comment.
The reason is pretty simple actually ... the telescope is deliberately pointed a bit off between individual frames so that artifacts move in a pattern which can be easily distinguished from that of asteroids.
To see how this works, let's say you center the telescope so that a particular start is exactly in the center of the field of view. Now imagine there is a speck of dust causing an artifact to appear exactly at the center, i.e right on top of the start You take image #1, then move the telescope slightly so that the start is a bit off of the center of the field of view and you take image #2 (which will have the artifact right in the center). Now, if you align the two images so the star is exactly in the same place, it will appear that it is the artifact that has moved between the frames!
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Foundren_Shi
in response to scibuff's comment.
Thanks a lot!
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