Monitoring X-ray Emission from SN 1986J

SN1986J ranks as one of the most luminous, X-ray bright supernovae ever observed. The X-ray emission is attributed to circumstellar interaction with the dense wind from its red supergiant progenitor star. Because X-ray bright supernovae are rare and relatively faint, only a small number have been observed in X-rays at an age of more than a year or two. I present results from recent Chandra and XMM observations of SN1986J which, combined with earlier ASCA and Rosat/PSPC data, yield an X-ray light curve spanning much of the first 20 years of the supernova's evolution. Combined with observations in other wave bands, these data provide strong constraints on models for this type IIn supernova.