University of Hertfordshire

By the same authors

An object that defies stereotypes: X-ray observations of SBS 1150+599A - the binary nucleus of PN G135.9+55.9

Research output: Chapter in Book/Report/Conference proceedingConference contribution


  • 902458

    Accepted author manuscript, 1.26 MB, PDF document


  • G. Tovmassian
  • J. Tomsick
  • R. Napiwotzki
  • L. Yungelson
  • G. Stasinska
  • M. Pena
  • M.G. Richer
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Original languageEnglish
Title of host publicationProcs Asymmetrical Planetary Nebulae IV
Publication statusPublished - 2007


We present X-ray observations of the close binary nucleus of the planetary nebula (PN) PN G135.9+55.9 obtained with the XMM satellite. The nebula is the most oxygen-poor PN known to date and is located in the Galactic halo. It is known to harbor a close binary nucleus of which only one component can be observed in optical-UV range. New X-ray observations show that the invisible component is a very hot compact star. This finding allows us to reconstruct the immediate past of the object and predict its future. The parameters of the binary components we determine strongly suggest that the precursor was a symbiotic supersoft X-ray source that finished its life by Roche lobe overflow. PN G135.9+55.9 is an excellent candidate for a future type Ia supernova.

ID: 1796786