| Telescope | MDM 1.3m |
| Date | 11/20/97 |
| Instrument | Echelle CCD |
| Filter | V |
| Exposure Time |
600 sec |
| Other | unprocessed |
Problem:This 600 second exposure has alot of dark current which is apparent in the strange large scale gradient (notice especially the upper lefthand corner) and horizontal streaks. Ignore the filter vignetting around the edges which was caused by using small filters. This same structure was not found in either flats or zeros. |
Fix:Cool the CCD to the correct temperature! If that does not work, take dark frames to subtract out the dark current. This involves taking exposures for some amount of time with the shutter closed. |
0 sec Zero frame with different structure
15 sec Twilight flat with different structure
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