| Description |
Carbon (and nitrogen) abundances, which can be used to constrainstellar evolution theory, are not well known in Galactic bulgeplanetary nebulae because the lines used are in the ultraviolet andare weak and difficult to measure accurately. We propose to measurethe C(+) abundance in a selection of low ionization PNe where it isthe dominant ion, by measuring the CII line at 157 microns. Thenitrogen line at 122 microns is used in conjunction with the line at6584 angstroms to accurately determine the electron temperature, whichnot only will make the nitrogen abundance more accurate, but willenable abundances to be determined for other ions measured in thevisual spectrum. |
