RADIO AND INFRARED-EMISSION FROM A [WC]-TYPE PLANETARY-NEBULA IN THE LMC

Radio continuum emission has been detected from a planetary nebula in the Large Magellanic Cloud: this is the first radio continuum detectio n for any planetary nebula outside our galaxy. The radio flux density is a factor of two lower than predicted from the HP flux. This could b e due either to a two-component morphology or to a stellar contributio n to the HP emission. We have modelled the optical and infrared spectr um using the photo-ionization code Cloudy: a very good fit is obtained if we assume the nebula is carbon rich. The derived diameter implies an evolutionary age of the nebula of < 1000 yr, similar to what is der ived from the IRAS colours alone. The central star, which is of [WC] t ype, has a much higher stellar temperature than Galactic [WC] stars sh owing similar circumstellar IRAS colours. An explanation could be that the expansion velocity of the nebula is lower than those of its galac tic counterparts. This radio detection indicates that accurate nebular luminosities could be determined from their radio emission for many L MC planetary nebulae.