An ISO and IUE study of planetary nebula NGC 2440 ^*

¹ SRON Laboratory for Space Research, PO Box 800, NL 9700 AV Groningen, The Netherlands
² Kapteyn Astronomical Institute, PO Box 800, NL 9700 AV Groningen, The Netherlands
³ Laboratory for Astronomy and Solar Physics, NASA–Goddard Space Flight Center, Greenbelt, MA 20771, USA

Corresponding author: J. Bernard Salas, J.Bernard@sron.rug.nl

Received: 13 November 2001
Accepted: 5 March 2002

Abstract

The infrared and ultraviolet spectra of planetary nebula NGC 2440 are presented. The observations were made by the Infrared Space Observatory (ISO) and the International Ultraviolet Explorer (IUE). These data, in conjunction with published optical observations have been used to derive electron temperature and density. The electron temperature increases with increasing ionization potential, from 11 000 to 18 000 K. The electron density has a constant value of 4500 cm^-3 in agreement with previous determinations. The chemical abundance has been derived for the following elements; helium, carbon, nitrogen, oxygen, neon, sulfur and argon. The ionization correction factor turns out to be very small for all species except sulfur.