y demonstrating
      % the computation.)
      %
      parallax = parallax_deg * <a href="cspice_rpd.html">cspice_rpd</a>;

      stardist = AU/tan(parallax);

      %
      % Scale the star's direction vector by its distance from
      % the solar system barycenter. Subtract off the position
      % of the spacecraft relative to the solar system barycenter;
      % the result is the ray's direction vector.
      %
      starpos = stardist * starpos;

      [pos, ltime] = <a href="cspice_spkpos.html">cspic