| Telescope | Las Campanas Obs. 1m |
| Date | 8/29/1997 |
| Instrument | SITe 1 |
| Filter | I |
| Exposure Time |
2 s |
Problem:It is not quite clear why this image looks the way it does. The stellar appearance is distorted and there is a partial doughnut to the lower right of the star. It turned out that the edge of the dome was located very close to where the telescope was pointing. Very likely, the cause of the problem is a reflection off some part of the dome. |
Fix:After the dome was moved out of the way, the next image was fine. By the way, the bright feature on the left side of the CCD (see panner) is a so-called "warm edge" of the CCD. This feature is visible only on very short exposures and goes away when processing the image. |
Another example of dome occultation
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