This line is the perpendicular bisector. The point of intersection of the perpendicular bisector and the original line is exactly halfway along the first line. If everything has been constructed ...
Publications of the Astronomical Society of the Pacific, Vol. 117, No. 833 (July 2005), pp. 711-720 (10 pages) ABSTRACT The shape of the line bisector for the prototype spectral line Fe i λ6253 was ...