| Telescope | MDM 1.3m |
| Date | 3/2/1998 |
| Instrument | Nellie CCD |
| Filter | R |
| Exposure Time |
900 s |
| Other | processed |
Problem:On this run, the dropout shutter was stuck shut and at the end of the night, as the target field set below the level of the dropout, the telescope field of view became occulted by the dropout. In this bias corrected, flattened image, the filter vignetting (already present) is more obvious and the donuts have not flattened out due to different illuminations in the flats vs. this image. |
Fix:Make sure the telescope is not occulted by the dome - make sure the dome is following the telescope or remember to move the dome yourself, and stop observing once the object is too low to be viewed through the dome opening. |
Another example of dome occultation
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