getting started - 
generation of simple lightcurve
-------------------------------

1 - measure object and comp stars for each image (qphot)
     * use aperture of 2-3 FWHM for now
     * make sure that obstime and exptime keywords are set

2 - dump qphot data to text file (txdump) - minimum required
    output quantities are obstime, exptime, mag, merr

3 - write program to create simple lightcurve output
     * output file should have 2 columns: time, deltamag
     * 'effective' time = obs start time + exptime/2
     * deltamag = variable mag - average of comp stars
      (the comp stars are assumed to be constant
      brightness, and hence are used as the reference level)

4 - plot deltamag vs. time using gnuplot or similar    

5 - enhancements
     * add errorbars to points
     * allow deltamag can be calculated using *any* of the objects
       (i.e., asteroid or any of the comp stars) as the 'variable.
       although the asteroid is the object of interest, plotting
       deltamags for each of the comp stars allows you to check 
       if they are really 'constant' brightness.
     * allow user to 'remove' one of the comps from the average
       if it is determined that it is really variable