Observations lead to changing theory behind Planetary Nebulae

[Gfamily]

When do Planetary Nebulae form? I've always read of them as being the last stage of smaller Red Giant stars; their outer layers being puffed off at their end of life. 

However, a listen to a recent Awesome Astronomy Podcast seems to suggest that 'it's a bit more complicated than that'. An interview with Dr Robert Wesson covered the results of the JWST imaging of the Southern Ring Nebula (one of the Initial Release images) and more recent imaging of M57 'our' Ring Nebula.

An article here about the JWST results that Dr Robert Wesson worked on, suggesting that PNs form within multiple star systems. 

https://scitechdaily.com/webb-space-telescope-reveals-mysterious-arcs-intricate-details-in-the-remains-of-a-dying-star/

and a copy of the recent paper on Arxiv.  https://arxiv.org/pdf/2308.09027.pdf

Further investigations are clearly required 

[robin_astro]

I don't think they are challenging the basic concept that planetary nebulae form from the outer layers ejected from red giants leaving a white dwarf, (A process which would still occur even in the absence of a binary companion) Just that the particular morphology and fine detailed structure (in this case and perhaps others) can be understood by considering  the presence of binary companions.  

[Gfamily]

1 hour ago, robin_astro said:

I don't think they are challenging the basic concept that planetary nebulae form from the outer layers ejected from red giants leaving a white dwarf, (A process which would still occur even in the absence of a binary companion) Just that the particular morphology and fine detailed structure (in this case and perhaps others) can be understood by considering  the presence of binary companions.  

The interview includes a comment that the number of PNs is significantly lower than would be expected given the population of suitably sized red giant stars.

If I heard it correctly, if almost all red giants of the right size were  to generate a PN, we'd expect to see far more of them. 

Also, (admittedly less convincingly) the observation is made that if the first two PNs studied by JWST show that a multiple star system is required to explain their structure (structure that was not previously obvious), then it may be more than a coincidence. But given the populations argument above, it may indeed be more than a coincidence. 

Hence, further analysis is required.

Edited October 6, 2023 by Gfamily

[robin_astro]

Ah ok I was just going on what was in the paper

Cheers

Robin

[Gfamily]

46 minutes ago, robin_astro said:

Ah ok I was just going on what was in the paper

Cheers

Robin

No problem - BTW,  well done on the 'place appropriate' name of your observatory - like like like ! 

[robin_astro]

9 hours ago, Gfamily said:

well done on the 'place appropriate' name of your observatory - like like like !

🙂

[Franklin]

Off topic but IMO PN's look nothing like planets, which just goes to show how bad old telescopes were? Modern optics are brill, they show it how it is! Unfortunately our amateur sized scopes are very limited so maybe the JWST is actually going to change our understanding of what we thought and deduced from the older observations. Even through my small refractors, what I see, does look like what science says but I'm interested in that knowledge being refined. Afterall, stars are the building blocks of the universe and to fully understand their life is of immense importance. The idea of old red giant stars "puffing" off their outer layers into space makes sense and that is what PN's looks like to me but I'm more than happy to accept a new and more accurate explanation.