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Gallery: Tempel 1 (2004-2005)

Observation made by Mike Wobser

Fig 1:

Image Parameter Details
Comments: Computer time was synchronized with the NIST atomic clock. I took 15 2-minute pictures in series starting about 13 minutes prior to predicted impact time and ending at 06:12 UT, when the comet dropped too low to the horizon to continue imaging. The images were dark subtracted and flat fielded. The second image was not used due to guiding difficulty during exposure. Using AIP for Windows, for each picture, I calculated the comet magnitude relative to a reference star in the image. I checked the magnitude difference of the reference star relative to a check star to determine measurement error. I averaged the first three comet brightness differences (from before the impact) and then subtracted each magnitude difference from this value to zero the data and show brightness increasing as a positive number. I plotted the resulting differences in MS Excel. The 99% confidence interval is +/- 0.06 magnitude for each data point. The recorded time for each picture is when the exposure is started so the measurements are an average of the magnitude difference for the subsequent 2 minutes. This mostly accounts for the magnitude starting to increase before the predicted impact time. However, even taking this lag into account, it still appears that the impact occurred about one minute before the predicted time of 05:52 UT. I was surprised at how slowly the magnitude increased.
Image Date/Time: 2005-07-04/05:39 - 06:13 UT
Observing Site: DasBoot 2 ½ Observatory
95° 31. 28.4. W
29° 20. 49.4. N
Rosharon, TX
Weather: clear
Telescope: Celestron C14 at f/6.93
Camera: SBIG ST-9e
Film: n/a
Exposure: 120 sec each
Filters: clear (IR blocked)

Table 1: Data about image.

Updated: 30-Jul-2013