LIGHT-CURVE MODELS FOR A PULSAR ORBITING A KERR BLACK-HOLE

We have studied the signal received by a distant observer from a pulsa r orbiting a stellar black hole. The binary system has a non-eccentric orbit and the most favourable configuration (edge-on) for observing t he influence of the black hole on the signal emitted by the pulsar. In particular, the influence of the spin of the black hole on the observ ed signal and the possibility of determining the spin are examined in detail. In the case of quasi-coalescent binary systems, with an initia l separation of approximate to 0.01 light-seconds, the flux-time relat ion is different for a non-rotating black hole from that for a black h ole with an extreme rotation velocity, The observational data obtained during the short lifetime of a quasi-coalescent system (<3 h) could b e marched with realistic theoretical profiles, which will be sensitive to the specific spin of the black hole. In the case of binary systems with an initial separation of approximate to 10 light-seconds, the pr obability of measuring the specific spin is briefly discussed on the b asis of the signal travelling in the surroundings of the black hole, w hich is strongly affected by the rotation.