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

blincoln 119 points 40 comments September 13, 2026
ras.ac.uk · View on Hacker News

Discussion Highlights (17 comments)

A_D_E_P_T

> 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.

N_Lens

That’s it Apollo! Spit it out, what’s in your mouth, spit it out now!

hnd9q09qk4

Did stellar abundance fits in grad school, getting the Teff systematics out took months.

run-good-code

When I saw the word 'Fingerprints', I thought it was a brilliant expression.

Martin_Silenus

I once ate a peanut too.

mturk

MESA, a piece of software referenced in this article, is a pretty incredible system. (Even referring to it as software underplays the extent of its community and impact.) Many people are involved in MESA and Bill Paxton was always quick to point out the many new folks that worked on it, but this article does a great job of celebrating his impact: https://www.kitp.ucsb.edu/news/an-accidental-astrophysicist It's amazing to me that he went from being the voice on the other end of the Mother Of All Demos to having such a major impact on stellar astrophysics during his "retirement." He passed away in 2025.

jcims

You have to get nearly halfway from the surface of the sun (photospere) to its core before the density of the sun’s material is equivalent to that of the earth.

regularfry

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?

kleton

Nominative determinism- first author's name "Mutlu Yıldız" means "happy star"

Razengan

That sentence is kind of scary. Imagine being a civilization on a planet that knows it's going to be swallowed by their sun.. (during the lifetime of the living members)

roshanabdullah1

and how exactly are we going to put our fingers into the sun?

huurtehoog

I find it endlessly fascinating that information cannot be destroyed and we keep finding more and more ways to read the universe at every scale!

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.

odyssey7

Clearly wasn’t a “planet” — failed catastrophically at clearing its neighborhood. The Royal Astronomical Society should be ashamed for publishing something so un-scientific. /s

fainpul

About that artist's impression with the blue spiral: wouldn't any planet or other object do one of these things: - approach and hit directly, without spiraling - approach, make a close fly-by and fly off into deep space again - be in a steady, eliptical orbit My knowledge is basically that of a Kerbal.

coolThingsFirst

how hysterical would it be if the Sun decided to pull the earth into it. Discussions on X, Reddit and HN titled "Is this it" or "Heat death is medically comfortable". Crazy stuff.

GolfPopper

On a similar note, the Large low-shear-velocity provinces (LLSVPs) are structures in Earth's lower mantle that are hyothized to be remnants of Theia (the planetary-scale body that collied with, resulting in the formation of the Moon): https://www.nature.com/articles/s41586-023-06589-1

Semantic search powered by Rivestack pgvector
6,460 stories · 59,045 chunks indexed