<p>Is it possible for a massive star of more than 1.4 solar masses (probably around 3 or more but below the threshold for type II) to collapse into a white dwarf and a planetary nebula, then go supernova as the ejected material falls back onto the white dwarf?</p>
<p>Edit: Have there been any candidates for such an event?</p>

CC BY-SA 4.0
2021-10-28T14:30:11.440Z
Why would the ejected material fall back?
Peter Erwin
CC BY-SA 4.0
2021-10-28T15:16:34.883Z
Yes this is plausible, but uncertain. @PeterErwin the ejected matter might not have enough momentum to fully escape the gravitational potential of the collapsing star. https://iopscience.iop.org/article/10.1086/307119/fulltext/35822.text.html
Daddy Kropotkin
CC BY-SA 4.0
2021-10-28T17:45:39.130Z
@DaddyKropotkin That article is about "accretion-induced collapse", where the accreted matter comes via mass transfer from a close binary companion. It has nothing to do with whether planetary nebula ejecta could somehow fall back.
Peter Erwin
CC BY-SA 4.0
2021-10-30T14:04:03.990Z
@PeterErwin "Fall back" is a rather vague phrase. An accretion disk could develop from the planetary nebula. https://astronomy.stackexchange.com/questions/29102/why-do-nebulae-turn-into-accretion-disks-but-planets-do-not Also, if matter could be transferred to the WD from a companion, then one, perhaps naively, might expect that a planetary nebula or common envelope could induce accretion.
Daddy Kropotkin
<star><supernova><white-dwarf>
Type Ia supernova by fallback?
WarpPrime
# Type Ia supernova by fallback?

(Asked by: username_0 on 2021-10-28)

Is it possible for a massive star of more than 1.4 solar masses (probably around 3 or more but below the threshold for type II) to collapse into a white dwarf and a planetary nebula, then go supernova as the ejected material falls back onto the white dwarf?

Edit: Have there been any candidates for such an event?

**Tags:** star, supernova, white-dwarf

> **Comments:**
> **username_1**: Why would the ejected material fall back?  
> **username_2**: Yes this is plausible, but uncertain. @PeterErwin the ejected matter might not have enough momentum to fully escape the gravitational potential of the collapsing star. https://iopscience.iop.org/article/10.1086/307119/fulltext/35822.text.html  
> **username_1**: @DaddyKropotkin That article is about "accretion-induced collapse", where the accreted matter comes via mass transfer from a close binary companion. It has nothing to do with whether planetary nebula ejecta could somehow fall back.  
> **username_2**: @PeterErwin "Fall back" is a rather vague phrase. An accretion disk could develop from the planetary nebula. https://astronomy.stackexchange.com/questions/29102/why-do-nebulae-turn-into-accretion-disks-but-planets-do-not Also, if matter could be transferred to the WD from a companion, then one, perhaps naively, might expect that a planetary nebula or common envelope could induce accretion.  

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## 0 answers

