Time and place of human origins from mt DNA data

Abstract

suggest an overall optical brightening of SN1987A, a property which is quite difficult to understand in models where the energy input is impulsive.Radioactive energy input (W.D. Arnett, preprint, 1987) will retard the decline and may even produce a slight increase in luminosity, so the light curve to date may not yet require pulsar input.But if there is an embedded rapidly spinning pulsar, then by August 1987 SN1987A should have become several magnitudes more luminous than it was in March and should ultimately show a spectrum with an extremely hard and polarized continuum from the underlying nebula.The nebular magnetic field will be quite large, in the range of 10°-10 2 gauss.Soon after that a very short period pulsar should emerge.As radio luminosity is normally small and not a strong function of period, and the nebular plasma frequency will be large, a radio pulsar will not be detected 25 •In the case of the Crab nebula a significant fraction of the slowdown energy is seen as hard pulsed radiation, so we may expect X-ray and perhaps optical pulses in the millisecond range to be seen from SN1987A 25 by 1990.The relatively specific predictions presented here (submitted 3 April 1987) allow one to test the hypothesis 12 -16 that the SN1987A supernova is being driven by a central pulsar.