Separation between θ ¹ Ori B ₁ and B ₄. Note how over 13 yr of observation there is little change in the separation (0.72 ± 0.23 mas yr ⁻¹; correlation 95%). The first data point is an speckle observation from the 6 m SAO telescope (Schertl et al. 2003), then Gemini/Hokupa'a observation (Close et al. 2003b), the next data point is from the MMT AO observation (Close et al. 2003b), the next from the LBT (Close et al. 2012b), and the last is from MagAO.