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BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20150212T103000
DTEND;TZID=Atlantic/Canary:20150212T113000
UID:iactalks-757
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/757
CREATED:2015-02-12T10:30:00+00:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:The discovery of a supernova type Ia progenitor at the heart of a p
 lanetary nebula
DESCRIPTION:The discovery of a supernova type Ia progenitor at the heart of
  a planetary nebula\nDr. David Jones\n\nI will report on the results of ou
 r paper published in Nature this       week, outlining the discovery of a 
 super-Chandrasekhar       double-degenerate binary system at the heart of 
 the planetary       nebula Hen 2-428.  Planetary nebulae (PNe) repres
 ent the final       stage in the evolution of low- and intermediate-mass s
 tars,       forming from the mass ejected by the star during its AGB evolu
 tion       before being ionised by the star's, now exposed, core.  As
        binarity is expected to play a key role in the formation of       a
 spherical PN morphologies, we have been intensively searching for       ne
 w binary central stars in a push towards a statistical sample.       
  One of our newly-discovered binary systems, lying at the heart of       H
 en 2-428, had a further surprise to reveal, with observations and       mo
 delling showing the system to consist of twin evolved stars with       a t
 otal mass greater than the Chandrasekhar limit.  The short       peri
 od of the system, only 4.2 hours, means that the two stars       will merg
 e together in approximately 700 Myr, resulting in a       Supernova Type I
 a.  While the super-Chandrasekhar merger of two       white dwarfs ha
 s long been considered a formation pathway for SN       Ia, this is the fi
 rst system found that is confirmed to be both       massive enough and in 
 a tight enough orbit to merge in less than a       Hubble time.
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