Planetary nebulae

It is now clear that a binary evolutionary pathway is responsible for a significant fraction of all planetary nebulae, and despite the futile resistance of some in the community, it may well be that binarity is a near requirement for the formation of an observable planetary nebula. With David Jones, I have written an extensive review, as well as a book on this subject.

These reviews were based on extensive work done with various colleagues and that involved finding new binaries inside Ethos-1, NGC 6326 and NGC 6778, Abell 70, Fleming 1, the Necklace, Hen 2-39, Hen 2-11, Hen 2-428, Hen 2-155 and Hen 2-161, Te 11, IC 4776, M 3-1, and NGC 2346.

Further to that, we have found some barium or carbon enriched companion to central stars of planetary nebulae, such as in Abell 70, the Necklace, and Hen 2-39, while the cool star inside LoTr 1 is not a barium star.

We have also looked in detail the connection between binarity and the Abundance Discrepancy Problem, as can be read here and here.

Also to note are the discovery of new faint northern galactic planetary nebulae made by amateurs, the enigmatic central star of the planetary nebula PRTM 1, that there is no ménage à trois at the heart of the Wedding Ring, and the fact that sometimes Nature tries to trick us!

Finally, I also led an extensive programme of imaging on FORS2, POPIPlaN.