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- The JKT is very sensitive to imbalance. Ensure the black
bag is fitted (and not fallen off) around the bottom of
the mirror cell. Another cause of imbalance is oil
accumulation in the Dec axis, if the oil scavenging system
is not working properly.
- If autoguiding, the star could be too faint to centroid
- Is it windshake?
- It's also possible that the mirror support system is
- Especially for sources that are in the west at a zenith distance
of more than 50 degrees, we have observed double images due to mirror
jumps. These jumps are typically a few to 15 arcsec long. If this is
the case, move to a different object (closer to zenith).
- The JKT secondary is mounted in a way that allows it to flop
when the telescope goes through the meridian. If you are observing on
the meridian you might experience this; the images are affected by a
jump of about half an arcminute.