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A_D_E_P_Tyesterday at 12:21 PM5 repliesview on HN

> 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 the same.


Replies

cfiggersyesterday at 12:23 PM

That's easy, they'll check whether there's one big fingerprint vs >10^10 little tiny fingerprints and conclude accordingly \j

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hydrogen7800yesterday at 1:44 PM

>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?

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andrewflnryesterday at 5:27 PM

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.

bell-cotyesterday at 1:29 PM

This, but how do they rule out the extra stuff landing in the sun much earlier - when the solar system was still a pre-solar nebula, and which bits would end up where (sun vs. planets vs. whatever) was far from settled?

omnicognateyesterday at 12:26 PM

> 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?

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