Visualizing Binary Black Hole Mergers in Eccentric Orbits 

We extend the open-source Binary Black Hole Explorer (binaryBHexp) package, enabling on-the-fly interactive visualization of eccentric BBH systems using numerical relativity (NR) data from the Simulating eXtreme Spacetimes (SXS) collaboration. From a range of configurations, the data-guided animations demonstrate the orbital motion, gravitational-wave emission, and evolution of the final BH remnant’s spin and recoil. The inclusion of eccentricity allows the visualization of expected gravitational bursts and spin-orbit coupling effects that are absent in circular models, providing researchers and educators with an intuitive view of relativistic dynamics. Some of the LIGO/Virgo/KAGRA detections have already shown possible hints of eccentricity, and these visualizations can be used to interpret and build intuition for eccentric binaries. Furthermore, as LISA gets closer to launch date, such visualizations will be essential for interpreting extreme mass ratio inspirals, which are expected to retain substantial eccentricity.