2/22/2022:
  - Dussault's spreadsheet with phase values matches my calculations of phase;
      that is, for a given image, his phase = my phase.  That's good.

  - my photometry suggests that the primary minimum is very close 
      to phase = 0.0.  A quadratic fit to data within +/- 0.03 phase
      yields minimum at phase = 0.998; a fit to within +/- 0.05 phase
      yields minimum at phase = 0.996

  - Dussault's photometry has a primary minimum close to zero;
      Quadratic fit to data within +/- 0.03 phase yields min at phase = 0.992;
      fit to data within +/- 0.05 phase yields min at phase = 0.985.


  - my photometry has secondary minimum at
             phase = +/- 0.05      min at phase = 0.509
             phase = +/- 0.10      min at phase = 0.499  (looks much better)

  - Dussault's photometry has secondary minimum at
             phase = +/- 0.05          no good fit
             phase = +/- 0.10      min at phase = 0.494
             phase = +/- 0.20      min at phase = 0.498