Astrophysics and Space Science

, Volume 279, Issue 1–2, pp 129–137

Modelling the Planetary Nebula

  • Don Pollacco
Article

Abstract

Deep narrow-band imaging and spectroscopy of the Planetary Nebula (PN)surrounding V4334 Sagittarii have been obtained since the onset of thethermal pulse in the star. Although of low surface brightness,narrow-band imaging suggests a ring structure maybepresent. Abundances, expansion rates and physical parameters for thenebula, derived from spectroscopy, show the plasma to be essentiallytypical of old evolved PN (within the errors of observation). The mostrecent data show little evidence of recombination indicating a verylow plasma electron density.Assuming no recombination has occurred, models of the PN spectrum wereconstructed using both simplistic ideas as well as sophisticatedphoto-ionisation codes. These show good agreement, and suggest that thepre-outburst UV radiation field would need to be powered by aprecursor with a surface temperature of T > 105K. The luminosity ofthis star is less well constrained by the models, and cannot be usedsolely to accurately determine its distance. However, by excludingunrealistic models we expect 250 > L/Lodot > 1000 or so. When plotted ona HR diagram for evolved stars this shows good agreement with thatexpected for a pre-last thermal pulse object.

Planetary Nebulae Stellar Evolution stars: individual(Sakurai's Object (V4334 Sgr)) 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Barker, T.: 1983, ApJ 267, 630.Google Scholar
  2. Duerbeck, H.W. and Benetti, S.: 1996, ApJ 468, L111.Google Scholar
  3. Duerbeck, H.W. and Pollacco, D.L.: 1996, IAUC 6328.Google Scholar
  4. Eyres, S.P.S., Richards, A.M.S., Evans, A. and Bode, M.F.: 1998, MNRAS 297, 905.Google Scholar
  5. Ferland, G.J.: 1996, University of Kentucky, Department of Physics and Astronomy, Internal Report.Google Scholar
  6. Iben, I. Jr. and MacDonald, J.: 1995, in: D. Koester and K. Werner, White Dwarfs, Springer, p. 48.Google Scholar
  7. Jacoby, G.H., de Marco, O. and Sawyer, D.G.: 1998, AJ 116, 1367.Google Scholar
  8. Kerber, F., Köppen, J., Roth, M. and Trager, S.C.: 1999, A&A 344, L79.Google Scholar
  9. Kerber, F., Palsa, R., Köppen, J., Blöcker, T. and Rosa, M.R.: 2000, ESO Messenger 101, 27.Google Scholar
  10. Köppen, J.: 1979, A&AS 35, 111.Google Scholar
  11. Pollacco, D.L.: 1999, MNRAS 304, 127.Google Scholar
  12. Rauch, T., Köppen, J. and Werner, K.: 1996, A&A 310, 613.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Don Pollacco
    • 1
  1. 1.APS DivisionQueen's University BelfastBelfastUK

Personalised recommendations