We perform the first general relativistic force-free simulations of neutron star magnetospheres in orbit about spinning and non-spinning black holes .
We find promising precursor electromagnetic emission : typical Poynting luminosities at , e.g. , an orbital separation of r = 6.6 R _ { NS } are L _ { EM } \sim 6 \times 10 ^ { 42 } ( B _ { NS,p } / 10 ^ { 13 } G ) ^ { 2 } ( M _ { NS } / 1.4 M _ % { \odot } ) ^ { 2 } erg/s .
The Poynting flux peaks within a broad beam of \sim 40 ^ { \circ } in the azimuthal direction and within \sim 60 ^ { \circ } from the orbital plane , establishing a possible lighthouse effect .
Our calculations , though preliminary , preview more detailed simulations of these systems that we plan to perform in the future .