EDP Sciences
Free access
Volume 502, Number 1, July IV 2009
Page(s) 189 - 197
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361/200912076
Published online 27 May 2009
A&A 502, 189-197 (2009)
DOI: 10.1051/0004-6361/200912076

Abundances in planetary nebulae: NGC 2792

S. R. Pottasch1, R. Surendiranath2, J. Bernard-Salas3, and T. L. Roellig4

1  Kapteyn Astronomical Institute, P.O. Box 800, NL 9700 AV Groningen, The Netherlands
    e-mail: pottasch@astro.rug.nl
2  Indian Institute of Astrophysics, Koramangala II Block, Bangalore-560034, India
3  Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853, USA
4  NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-1000, USA

Received 16 March 2009 / Accepted 15 May 2009

The mid-infrared spectrum of the rather circular planetary nebula NGC 2792 taken with the Spitzer Space Telescope is presented. This spectrum is combined with the ultraviolet IUE spectrum and with the spectrum in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebula is then calculated in two ways. First by directly calculating and adding individual ion abundances, and secondly by building a model nebula that attempts to reproduce the observed spectrum. Because it is now possible to include the nebular temperature gradient, the chemical composition is more accurate than has been given earlier in the literature. Discussion of both the central star and the evolution of the star-nebula is then given.

Key words: ISM: abundances -- planetary nebulae: individual: NGC 2792 -- infrared: ISM -- ISM: lines and bands

© ESO 2009