Deep Impact Observations of Comet 9P/Tempel 1
_____________________________________________

San Diego State University/Mt. Laguna Observatory  2005 July 05 UT

SDSU/MLO Investigators:               Student Investigators:
Dr. Paul Etzel                        Ms. Karen Hutchins
Dr. William Welsh                     Mr. Carlos Vargas
Dr. Robert Leach                      Mr. Merek Chertkow
Mr. Scot Streit                       Mr. Tyler Mitchell

Data Acquisition:
 1-m Telescope + "CCD2005" + R-band filter
 0.4 arcsec/pix binned 2x2 and subarray/window to 300x300 pix
 4 sec exposures + ~1.43 s readout time
 1859 images, spanning 2:50:43.9s
 photometric, dark sky; seeing 2.1-2.3 arcsec fwhm

Data Calibration:
 Bias and flat field calibrated, then aligned using IRAF.

Movie Parameters:
 Every 10th frame displayed, hence ~54 sec between frames.
 Linear scaling was used.
   mpg display scaling: min=5 (black) max=210 (white).
   gif display scaling: min=15(black) max=300 (white).
 For color, the "BB" color lookup table in ds9 was used. This color was 
 chosen because it provides a pleasing movie, but also because it 
 roughly mimics the R-band in which the data were acquired.

Duration of the mpeg animations:
               Shorter movies           Longer movies
 Start   time: 04:48:12.1 UT            04:48:12.1 UT
 Finish  time: 07:05:47.7 UT            07:22:27.6 UT
 Elapsed time:  2:17:35.6	         2:34:15.5
 Total frames:  151                      169

The gif animation spans 2 hours 43 min.
The two normalized mpeg movies have been created such that the sky
background is equal to 1.00 in all the frames. This produces more
appealing movies since the sky is not getting brighter as the
observations continue to larger distances from the zenith.


Miscellaneous Movie Notes:
- The changing sharpness is due to the instantaneous changes in the 
  atmosphere (known as "seeing" or informally as "twinkling"). With
  short exposures (4 seconds), this effect is quite noticeable.~~~
- Occasional cosmic rays appear as very bright pixels.
- Towards the end of the movie the sky gets brighter. This is due to
  the telescope looking closer to the horizon where the sky glows 
  brighter.
- Erratic changes in the position of the comet in the images are due 
  to the tracking/guiding of the telescope combined with atmospheric 
  changes. The telescope is designed to track the motion of the stars, 
  but the comet is moving relative to the stars. So the fine pointing 
  of the telescope was done by hand by watching the images and pushing 
  "move telescope" buttons frequently. However, in the data calibration 
  steps, the motion of the comet has been removed by aligning the images 
  with the center of comet in each frame. Two jumps can still be seen in
  the animated gif.
- The mpeg file was created from calibrated FITS files using the image 
  display software "ds9".
- The gif file was created with Adobe Photoshop and Image Ready

Acknowledgements:
- This research was enabled by the High Performance Wireless Research
  and Education Network (HPWREN) managed by Hans-Werner Braun and Frank
  Vernon of the University of California, San Diego (UCSD) with support
  from National Science Foundation Grant Numbers 0087344 and 0426879.
- This research has made use of SAOImage DS9, developed by Smithsonian 
  Astrophysical Observatory.
- WFW acknowledges support from Research Corporation.
- MAC acknowledges support from the NSF REU program "CSUURE" administered
  by SDSU.