[HN Gopher] A supernova star that erupted continuously for about...
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A supernova star that erupted continuously for about 1,000 days
Author : belter
Score : 67 points
Date : 2022-10-08 17:58 UTC (4 days ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| jwuphysics wrote:
| This is definitely an interesting object, but based on the recent
| literature[0] it seems most astronomers attribute the odd
| signatures to interactions with its circumstellar material. The
| Wikipedia article focuses a bit too much on the initial Nature
| paper authored by Arcavi et al...
|
| [0]
| https://ui.adsabs.harvard.edu/search/fq=%7B!type%3Daqp%20v%3...
| ncmncm wrote:
| Binary stars are so common, it surprises me to find so few
| phenomena that involve companions. It was gratifying to see
| suggested a neutron star diving through a diffuse neighbor.
|
| There are of course type Ia supernovas. ("Fhtagn!")
| denton-scratch wrote:
| The article says this is a Type II-P supernova; the wikipedia
| link says that's a core-collapse supernova, and results in a
| neutron star. It says the collapse of the core occurs in seconds.
| I suppose the production of heavy elements and radiation must
| continue for days or weeks.
|
| If a big star's core collapses to a neutron star in seconds, and
| the outer parts of the star get blown away due to reaching escape
| velocity, how does this thing keep blazing for four years? Is it
| really not a core-collapse supernova?
|
| The article also says:
|
| > Since 1954, the star has exploded six times.
|
| How does that work? The thing can't be a core-collapse supernova;
| there's only so many times your core can collapse to a neutron
| star (roughly once).
|
| It sounds from the WP article that what is being seen isn't the
| supernova explosion (which can surely only occur once), but the
| impact of a shockwave on a previous shell of exploding stuff.
| Which makes me suppose it's some kind of type I supernova?
| vikingerik wrote:
| The most likely hypothesis seems to be that there is a lot of
| interstellar material around the star, such that the ejecta is
| colliding with that and keeping it hot to keep glowing. It was
| a core-collapse supernova initially; the energy released from
| that is being absorbed and more slowly re-emitted by the thick
| surrounding material. (Thick in astronomical terms is still
| something like two hydrogen atoms per cubic meter.)
| denton-scratch wrote:
| Yeah, that's roughly what I figured (IANAA). But it still
| seems hard to explain six flashes bright enough to appear
| like a supernova. I'd expect the flash of any kind of
| supernova to be brighter than the flash of a shockwave
| hitting a shell of gas. But I know nothing.
|
| And anyway, for the shockwave from a supernova explosion to
| hit the shell of expanding gas from a previous explosion,
| that still seems to imply two supernova explosions from the
| same star. The only way I know that can happen is in a binary
| system.
| lazide wrote:
| Perhaps it's a hybrid? Original core collapse, then
| accretion of in falling material after the shock from the
| last explosion dissipates, causing spontaneous
| fusion/degeneracy again and re-explosion?
| belter wrote:
| "A Star That Would Not Die" - https://spaceref.com/science-and-
| exploration/a-star-that-wou...
| rtanks wrote:
| Interesting
| willmadden wrote:
| If you want to go down the rabbit hole watch this video from
| suspicious0bservers.org.
|
| Start at 7:24 to skip the intro.
|
| https://www.youtube.com/watch?v=B_zfMyzXqfI
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(page generated 2022-10-12 23:01 UTC)