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

133 points by blincoln 4d ago

odyssey7 3d ago
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
huurtehoog 3d ago
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!
roshanabdullah1 3d ago
and how exactly are we going to put our fingers into the sun?
Razengan 3d ago
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)
spectraldrift 3d ago
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 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.
- birdsongs 3d ago
  There's been a lot of changed titles recently, and it is quite annoying. I feel like that used to get corrected.
kleton 3d ago
Nominative determinism- first author's name "Mutlu Yıldız" means "happy star"
- deleted 3d ago
  [deleted]
regularfry 3d ago
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?
- accrual 3d ago
  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.
- gus_massa 3d ago
  Neither an astrophysics. I skimmed the paper. IIUC the collision with the planet mixed internal layers of the Sun and a lot of the Lithium went to the core and got fussed with Hydrogen. PS: The paper says that that actual A(Li)=1.1 instead of the expected A(Li)=3.3. I needed a lot of search to understand it until Gemini kindly liked this page. https://astronomy.stackexchange.com/questions/61814/what-do-lithium-abundance-numbers-mean-in-catalogs-like-hypatia https://astronomy.stackexchange.com/questions/61814/what-do-... A(Li)=1.1 means the Li/H ratio is 10^(-10.9) = 10^(-8.9)% A(Li)=3.3 means the Li/H ratio is 10^(-9.7) = 10^(-7.7)%
Martin_Silenus 4d ago
I once ate a peanut too.
A_D_E_P_T 4d ago
> 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.
- andrewflnr 3d ago
  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.
- cfiggers 4d ago
  That's easy, they'll check whether there's one big fingerprint vs >10^10 little tiny fingerprints and conclude accordingly \j
  - amelius 4d ago
    Not if the EU has a say about it. Those rocks and pebbles have a right to privacy and fingerprinting is off the table.
    - snovv_crash 3d ago
      You sound bitter about this.
    - rotringlvr 3d ago
      [dead]
- omnicognate 4d ago
  > 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?
N_Lens 4d ago
That’s it Apollo! Spit it out, what’s in your mouth, spit it out now!
hnd9q09qk4 4d ago
Did stellar abundance fits in grad school, getting the Teff systematics out took months.
run-good-code 4d ago
When I saw the word 'Fingerprints', I thought it was a brilliant expression.
mturk 4d ago
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 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 4d ago
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.
fainpul 3d ago
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.
- wongarsu 3d ago
  There are obviously many things KSP's patched conics approximation can't account for, like lagrange points or how orbits often get twisted around over time, or how the small effects from all the other solar bodies add up to be significant over time. The simplest thing that comes to mind here is that KSP simulates a mature solar system, where space is mostly empty. This event happens in an early solar system, where there's lots of stuff everywhere. Running into stuff can steal some of the planet's momentum, causing it to fall deeper, causing it to run into more stuff But planetary migration can be a lot more complicated than that. [1] has an overview. You might also enjoy the Grand Tack hypothesis [2] which involves early Jupiter spiraling into the inner solar system until around the orbit of current-day Mars, before eventually reversing course and getting to its current orbit further out 1: https://en.wikipedia.org/wiki/Planetary_migration https://en.wikipedia.org/wiki/Planetary_migration 2: https://en.wikipedia.org/wiki/Grand_tack_hypothesis https://en.wikipedia.org/wiki/Grand_tack_hypothesis

133 points by blincoln 4d ago

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

huurtehoog 3d ago

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!

roshanabdullah1 3d ago

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

Razengan 3d ago

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)

spectraldrift 3d ago

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 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.

birdsongs 3d ago
There's been a lot of changed titles recently, and it is quite annoying. I feel like that used to get corrected.

kleton 3d ago

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

deleted 3d ago
[deleted]

regularfry 3d ago

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?

accrual 3d ago
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.
gus_massa 3d ago
Neither an astrophysics. I skimmed the paper. IIUC the collision with the planet mixed internal layers of the Sun and a lot of the Lithium went to the core and got fussed with Hydrogen. PS: The paper says that that actual A(Li)=1.1 instead of the expected A(Li)=3.3. I needed a lot of search to understand it until Gemini kindly liked this page. https://astronomy.stackexchange.com/questions/61814/what-do-lithium-abundance-numbers-mean-in-catalogs-like-hypatia https://astronomy.stackexchange.com/questions/61814/what-do-... A(Li)=1.1 means the Li/H ratio is 10^(-10.9) = 10^(-8.9)% A(Li)=3.3 means the Li/H ratio is 10^(-9.7) = 10^(-7.7)%

Martin_Silenus 4d ago

I once ate a peanut too.

A_D_E_P_T 4d ago

> 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.

andrewflnr 3d ago
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.
cfiggers 4d ago
That's easy, they'll check whether there's one big fingerprint vs >10^10 little tiny fingerprints and conclude accordingly \j
- amelius 4d ago
  Not if the EU has a say about it. Those rocks and pebbles have a right to privacy and fingerprinting is off the table.
  - snovv_crash 3d ago
    You sound bitter about this.
  - rotringlvr 3d ago
    [dead]
omnicognate 4d ago
> 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?

N_Lens 4d ago

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

hnd9q09qk4 4d ago

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

run-good-code 4d ago

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

mturk 4d ago

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 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 4d ago

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.

fainpul 3d ago

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.

wongarsu 3d ago
There are obviously many things KSP's patched conics approximation can't account for, like lagrange points or how orbits often get twisted around over time, or how the small effects from all the other solar bodies add up to be significant over time. The simplest thing that comes to mind here is that KSP simulates a mature solar system, where space is mostly empty. This event happens in an early solar system, where there's lots of stuff everywhere. Running into stuff can steal some of the planet's momentum, causing it to fall deeper, causing it to run into more stuff But planetary migration can be a lot more complicated than that. [1] has an overview. You might also enjoy the Grand Tack hypothesis [2] which involves early Jupiter spiraling into the inner solar system until around the orbit of current-day Mars, before eventually reversing course and getting to its current orbit further out 1: https://en.wikipedia.org/wiki/Planetary_migration https://en.wikipedia.org/wiki/Planetary_migration 2: https://en.wikipedia.org/wiki/Grand_tack_hypothesis https://en.wikipedia.org/wiki/Grand_tack_hypothesis