A Parallactic Distance of 389_-21⁺²⁴ Parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations

We determine the parallax and proper motion of the flaring, nonthermal radio star GMR A, a member of the Orion Nebula Cluster, using Very Long Baseline Array observations. Based on the parallax, we measure a distance of 389 pc to the source. Our measurement places the Orion Nebula Cluster considerably closer than the canonical distance of 480 ± 80 pc determined by Genzel et al. A change of this magnitude in distance lowers the luminosities of the stars in the cluster by a factor of ~1.5. We briefly discuss two effects of this change—an increase in the age spread of the pre-main-sequence stars, and better agreement between the zero-age main sequence and the temperatures and luminosities of massive stars.