The goal of this campaign is to obtain scientifically useful observations over a period of about 48 hours. During this campaign, the morning sky will be dark since the moon is at first quarter. We need you to begin observations on the morning of July 8 (local time), then again during the morning of July 9. The comet is visible from the southern and northern hemispheres and has a predicted apparent visual magnitude of about 15 (last week, one of our observers reported the observed magnitude could be as faint as 17).

Observing procedures and a link to an ephemeris generator can be found at http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html. Please contact me if you have any questions! In general, we need you to:

1) Make images of the comet using the following filters  

   a) Photometric V and R or R and G filters from a photographic RGB
      set (you may try the B filter, but comets do not emit much in
      this band).  If you use photographic R and G filters, you must
      include an infrared-cutoff filter.  We will use V- and G-filtered 
      images for photometry and R-filtered images for coma structure and
      dust activity studies.

   b) Clear (or no filter).  We will use these images to monitor overall
      brightness changes over time and heliocentric distance.

   NOTE:  Multiple, short exposures (1-3 minutes, with accurate tracking)
          allow us to do the most analysis.  Single, long exposures, where
          a magnitude of 19.5 is reached, can be used for brightness
          analysis even if the comet trails a little.
   NOTE:  Comet images need to contain a few stars so that we can
          callibrate your images.

2) Make 3-5 flat frames for each of the filters you observe with.

3) If you have a nitrogen-cooled CCD, make 5-10 bias frames and 3-5
   dark frames using an exposure time of 1-2 minutes.

   If you have a thermoelectrically-cooled CCD (most commercial
   CCDs):

      If your CCD software performs automatic dark frame subtraction,
      turn this feature on and indicate this in your observing log.

      If your CCD software does not perform automatic dark frame
      subtraction, make 3-5 dark frames using the same exposure times
      used for the comet images.

4) Take images of at least 3 standard stars using each filter.  A
   list of standard stars and instructions for choosing stars will
   be available by July 1 at:

   http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html#sec9
  
5) Keep an observing log!  Include the longitude and lattitude of your
   observatory in your log.  Also, include weather conditions. For a
   sample, go to:

      http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html#sec2 
   
6) Format all images as FITS.

7) Transfer FIT images to Stef McLaughlin using an anonymous FTP 
   process.  Instructions are at the end of this email!