Gaia DR2 parallaxes of all stars in the direction of the σ Ori cluster versus their Gaia DR2 distance to the cluster center taken at (RA, Dec) = (84.675, −2.6) deg from Simbad. The dashed and dotted horizontal lines indicate the mean and the limits of one standard deviation, respectively, of the parallaxes as determined by Caballero (2018) from cluster members. The positions of σ Ori C, D, and E in the diagram are indicated by the blue and red filled circles and the green filled diamond, respectively.