DISCUSSION: Symbiotic nebulae and the link with PNe V1016 Cyg Romano Corradi Hugo Schwarz Hans van Winckel Romano Corradi Hugo Schwarz Hans van Winckel He 2-147 He 2-104 R Aqr Mike Bode Joel Kastner Adam Frankowski Claudio Pereira CH Cyg BI Cru HM Sge

Symbiotic nebulae are post-PN nebulae The story from my point of view. I do not know if you recognize the three persons here. Hans van Winckel and I were Hugo’s students, at the time. He tried to teach us that nebulae around symbiotic stars are nebulae produced by binary systems after they have already produced a PN. At that time, we did not have a strong opinion on this, but we promised ourselves to think about it, and in fact… 1991, ESO Chile…

But they are wearing a swimsuit as a hat!!! They are pre-PN But they are wearing a swimsuit as a hat!!! Hans and I meet again in 1994, and concluded that symbiotic nebulae were objects in a phase just prior to the formation of a PN. [but how to trust two guys dressing in such a way?]. However, another years later also Hugo moved to the Canary Islands, and he came back trying convincing us that symbiotic nebulae are post-PN nebulae, this time I would say using sort of ‘religious’ arguments... 1994, Tenerife…

1999, Tenerife… They ARE post-PN nebulae no no, they are… who is he/she?

…just nebulae around symbiotic stars, similar to PNe and often misclassified with them because: Symbiotic nebulae have high-density ionized cores as young PNe, and similar exciting conditions, thus similar spectra (but also similar to completely different objects, like eta Car!!!) Symbiotic nebulae are similar to PNe because they are also formed by interacting stellar winds (but the origin of the fast wind is different, as it follows nova-like outbursts)

The formation of symbiotic nebulae red giant wind 1% 99% accretion fast winds from the WD during nova-like eruptions ionising photons winds interaction + photoionisation = Symbiotic nebulae simulate PN evolution  

name core Ne Ha wings tot [km s-1] central absorption FeII emission shape central star M 2-9 107 11000  Mz 3 >105 2500 - He 2-25 107.5 3500 ? Th 2-B 3000 M 1-91 106.5 extended O5 + red excess He 2-428 >1010 135 Hb 12 19W32 K0-M2 Abell 79 F0 Candidate misclassified PNe (Corradi, Mikolajewska & Mahoney eds, 2003, ASP Conf. Ser.)

Near-IR diagnostic diagram Bipolar PNe PNe Schmeja & Kimeswenger 2001 A&A 377, L18

but…. Hora et al. 1999 ApJS 124, 195 M 2-9 Strong dust continuum component, no direct evidence of a cool companion