Astrometric signature of Barnard’s Star b, calculated from the RV-analysis MCMC chain of Ribas et al. (2018), as a function of the simulated sin i chain. The horizontal lines indicate the detection thresholds discussed in the main text. The pessimistic–optimistic single-epoch accuracy range of the four instruments discussed in the main text are specified with the colored arrows. The plot is truncated at 1250μas following the upper limit set by Benedict et al. (1999). As a reference, the planet mass corresponding to each sin i value (assuming m_p sin i = 3.23 M_⊕) is indicated at the top of the panel.