Testing the binary hypothesis with VPHAS+: searching for planetary nebula central star infra-red excess

Helen Barker

University of Manchester, UK

The origins of planetary nebulae (PNe) and their morphologies remains unclear. Theoretical works suggest that a single AGB star is unable to shape mass loss in such a way as to create the highly non-spherical nebulae we observe, and the deficiency in the number of observed Galactic PNe relative to estimates from population synthesis suggest that only a subset of the 1-8M_⊙ progenitor stars form a PN. This gives weight to the binary hypothesis, which states that PNe are preferentially formed by central stars (CS) in binary systems.

To test the binary hypothesis, the well-known binary fraction of the progenitor population must be compared to that of CSPN. Assuming the companion is a cool star, binarity can be detected at any separation through detection of excess infra-red emission. This poster explores whether VPHAS+ (VST Photometric H-Alpha Survey of the Southern Galactic Plane and Bugle) provides the high precision photometry needed for this technique.

Last update: