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'Fingerprints' inside the Sun could reveal if it once swallowed a planet

ras.ac.uk

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Re: 'Fingerprints' inside the Sun could reveal if it once swallowed a planet

#21

Post by tracerbulletx »

hydrogen7800 wrote: post #11
A_D_E_P_T wrote: post #2

> Their results favour a scenario in which the young Sun engulfed a super-Earth around 5–10 times the mass of Earth Given the state of the early solar system, it would be surprising if the Sun didn't swallow a lot of metallic and carbonaceous rocks and pebbles. But it seems unclear to me how the researchers would distinguish between one super-Earth and >10^10 smaller rocks? Chemically I feel the two would be largely…

>But it seems unclear to me how the researchers would distinguish between one super-Earth and >10^10 smaller rocks? I have a similar feeling when life on earth is suggested to be "alien", arriving via debris in the solar system as the earth formed. Isn't everything in the solar system coalesced from the same debris?

That always felt like a deus ex machina answer to me too. We don't know exactly how abiogenesis happened on earth so some people just like to cut off the chain of causation with the idea of, "it was seeded"... but then how did abiogenesis happen elsewhere?

I don't think that's a very popular theory among anyone who knows what they're talking about though.

Re: 'Fingerprints' inside the Sun could reveal if it once swallowed a planet

#27

Post by accrual »

regularfry wrote: post #22

Has someone got a quick explainer for why adding a planet would result in less lithium? Is it just that a super-earth would be big enough and have so little lithium that it would measurably water down the other elements?

Not an astrophysicist, but since they mentioned the lithium is depleted, I wonder if that implies the collision of a planetary body with a sun would consume or react with the solar lithium.

Re: 'Fingerprints' inside the Sun could reveal if it once swallowed a planet

#28

Post by spectraldrift »

This might just be me, but I find metaphors like ''Fingerprints' inside the Sun' harder to read than the title of the original paper, which is probably what should be linked here per HN submission guidelines:

> Planetary engulfment as a solution to solar-model discrepancies and its implications for planetary systems https://doi.org/10.1093/mnras/stag1527

For the press release, something like The Real Sun and Its Simulations Disagree. A Planet That Fell In Early Might Explain It. might be easier to follow.

Re: 'Fingerprints' inside the Sun could reveal if it once swallowed a planet

#29

Post by andrewflnr »

A_D_E_P_T wrote: post #2

> Their results favour a scenario in which the young Sun engulfed a super-Earth around 5–10 times the mass of Earth Given the state of the early solar system, it would be surprising if the Sun didn't swallow a lot of metallic and carbonaceous rocks and pebbles. But it seems unclear to me how the researchers would distinguish between one super-Earth and >10^10 smaller rocks? Chemically I feel the two would be largely…

I don't fully follow (not being an astrophysicist), but it seems like the depth of the metallic material within the star matters a lot for their model. A planet can "bury" it (their word) a lot deeper than small rocks by physically sinking in before it gets destroyed. Sections 4.2 and 4.5 (among others I assume) in the actual paper linked above talk about this stuff.

Re: 'Fingerprints' inside the Sun could reveal if it once swallowed a planet

#30

Post by andrewflnr »

monster_truck wrote: post #15
omnicognate wrote: post #5

Earlier quoted context omitted.

> Researchers also found that such a world could survive its passage through the Sun's outer layers while losing very little mass, which suggests that planets may leave detectable fingerprints inside their host stars long after they have disappeared. So I guess the large size would have permitted it to smuggle stuff into the core that would have just vaporised in the corona if carried by many smaller objects?

Sounds reasonable to me. But also what the fuck happens to the core of such a planet when that happens? We aren't actually sure what gave our core the spin it has, right? I'm not fully awake yet but I think it's plain where I'm going with this.

It's not plain to me where you're going. But the answer about the core of a planet engulfed by the sun is that it vaporizes eventually, just not right away.
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