THE BRIGHT CORE AND DOUBLE HALO OF THE PLANETARY-NEBULA NGC-40

Deep, narrow-band CCD images in the visible, nebular emission lines of the planetary nebula NGC 40, obtained with the San Pedro Martir teles cope, have revealed the presence of two haloes to the barrel-shaped ne bular core and a jet-like feature projecting from it. A faint, diffuse inner halo is approximate to 90 '' diameter whereas the outer halo ha s prominent filaments embedded in patchy emission within a region appr oximate to 4' diameter. Spatially resolved longslit spectra of the H a lpha and [N II]6584 Angstrom emission lines have been obtained, using the Manchester echelle spectrometer combined with the Isaac Newton tel escope, from the bright core of NGC 40, its two haloes and the jet-lik e phenomenon. Hundreds of times fainter C II 6578 Angstrom profiles we re obtained only from the bright core. The outer filamentary halo is s hown to be relatively inert, emitting narrow, single lines on the syst emic heliocentric radial velocity of -31 km s(-1). Its internal turbul ent motions are shown to be approximate to 7 km s(-1) and its electron temperature T-e = 7400 +/- 160 K. The nebular emission lines from the inner, diffuse, spherical halo are split in places by less than or eq ual to 50 km s(-1) which is approximately the splitting found over the bright nebular core. The jet-like feature is kinematically associated with the receding end of the barrel shaped core and does not have any of the kinematical characteristics expected of a true jet. The creati on of all of these phenomena are discussed within current evolutionary models of planetary nebulae.