The orbit of Theta1 Orionis C

The first VLTI image is that of the double star Theta1 Orionis C in the Orion Nebula Trapezium. From these, and several other observations, the team of astronomers, led by Stefan Kraus and Gerd Weigelt from the Max-Planck Institute in Bonn, could obtain the full orbit of the two stars in the system, and derive the total mass of the two stars (47 solar masses) and their distance from us (1350 light-years).
This montage shows a wide-view of the Orion Nebula as seen with ISAAC on ESO’s Very Large Telescope, a zoom of the Trapezium obtained with the NASA/ESA Hubble Space Telescope, and the orbit derived by the astronomers, using several facilities over 11 years. The VLTI images created for this system have an extraordinary spatial resolution of about 2 milli-arcseconds.