Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-25T23:03:50.703Z Has data issue: false hasContentIssue false
  • English
  • Français

[WN] central stars of planetary nebulae

Published online by Cambridge University Press:  08 August 2017

H. Todt ,
B. Miszalski ,
J. A. Toalá  and
M. A. Guerrero
H. Todt
Affiliation:
Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany email: htodt@astro.physik.uni-potsdam.de
B. Miszalski
Affiliation:
South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa; Southern African Large Telescope Foundation, PO Box 9, Observatory 7935, South Africa
J. A. Toalá
Affiliation:
Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), 10617 Taipei, Taiwan, Republic of China Instituto de Astrofísica de Andalucía, IAA-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain
M. A. Guerrero
Affiliation:
Instituto de Astrofísica de Andalucía, IAA-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

While most of the low-mass stars stay hydrogen-rich on their surface throughout their evolution, a considerable fraction of white dwarfs as well as central stars of planetary nebulae have a hydrogen-deficient surface composition. The majority of these H-deficient central stars exhibit spectra very similar to massive Wolf-Rayet stars of the carbon sequence, i.e. with broad emission lines of carbon, helium, and oxygen. In analogy to the massive Wolf-Rayet stars, they are classified as [WC] stars. Their formation, which is relatively well understood, is thought to be the result of a (very) late thermal pulse of the helium burning shell. It is therefore surprising that some H-deficient central stars which have been found recently, e.g. IC 4663 and Abell 48, exhibit spectra that resemble those of the massive Wolf-Rayet stars of the nitrogen sequence, i.e. with strong emission lines of nitrogen instead of carbon. This new type of central stars is therefore labelled [WN]. We present spectral analyses of these objects and discuss the status of further candidates as well as the evolutionary status and origin of the [WN] stars.

Keywords

Stars: abundancesStars: AGB and post-AGBStars: atmospheresStars: mass-lossStars: PN PB 8Stars: IC 4663Stars: Abell 48Stars: PMR 5Stars: Wolf-Rayet
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 12 , Symposium S323: Planetary Nebulae: Multi-Wavelength Probes of Stellar and Galactic Evolution , October 2016 , pp. 174 - 178
Copyright
Copyright © International Astronomical Union 2017 

References

Acker, A. & Neiner, C., 2003, A&A, 403, 659 Google Scholar
Althaus, L. G., Serenelli, A. M., Panei, J. A., et al. 2005, A&A, 435, 631 Google Scholar
Crowther, P. A. & Walborn, N. R., 2011, MNRAS, 416, 1311 CrossRefGoogle Scholar
DePew, K., Parker, Q. A., Miszalski, B., De Marco, O., Frew, D. J., Acker, A., Kovacevic, A. V., Sharp, R. G., 2011, MNRAS, 414, 2812 CrossRefGoogle Scholar
Frew, D. J., Bojičić, I. S., Parker, Q. A., et al. 2014, MNRAS, 440, 1345 CrossRefGoogle Scholar
García-Rojas, J., Peña, M., & Peimbert, A., 2009, A&A, 496, 139 Google Scholar
Herwig, F., 2001, Ap&SS, 275, 15 Google Scholar
Iben, I. Jr. & MacDonald, J. 1995, in Lecture Notes in Physics, Berlin Springer Verlag, Vol. 443, White Dwarfs, ed. Koester, D. & Werner, K., 48Google Scholar
Méndez, R. H. 1989, in IAU Symposium, Vol. 131, Planetary Nebulae, ed. Torres-Peimbert, S., 261–272CrossRefGoogle Scholar
Miszalski, B., Crowther, P. A., De Marco, O., et al. 2012, MNRAS, 423, 934 CrossRefGoogle Scholar
Morgan, D. H., Parker, Q. A., & Cohen, M., 2003, MNRAS, 346, 719 CrossRefGoogle Scholar
Reindl, N., Rauch, T., Werner, K., Kruk, J. W., & Todt, H., 2014, A&A, 566, A116 Google Scholar
Riesgo-Tirado, H. & López, J. A. 2002, in RMxAC, ed. Henney, W. J., Franco, J., & Martos, M., Vol. 12, 174–174Google Scholar
Smith, L. F. & Aller, L. H., 1969, ApJ, 157, 1245 CrossRefGoogle Scholar
Todt, H., Peña, M., Hamann, W.-R., & Gräfener, G., 2010, A&A, 515, A83 Google Scholar
Wachter, S., Mauerhan, J. C., Van Dyk, S. D., Hoard, D. W., Kafka, S., Morris, P. W., 2010, AJ, 139, 2330 CrossRefGoogle Scholar
Werner, K. 2012, in IAU Symposium, Vol. 283, IAU Symposium, 196–203CrossRefGoogle Scholar