What-If 0151: "Sun Bug"

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What-If 0151: "Sun Bug"

Postby leapoffaith28 » Tue Jul 19, 2016 7:17 pm UTC

Sun Bug

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xkcd wrote: Since mass is proportional to length cubed, our firefly would weigh (3×10^31)^(3/2)=1.6×10^47 times as much as a normal firefly, which works out to about half as much as the entire Milky Way galaxy.


This is half the mass of the Milky Way? Doing some rudimentary calculations, the galaxy is 1 trillion times the mass of the sun, which means a cube of 10,000 suns on each side.

The density of a human works out to a little more than 1000 kg/m^3 (water), and sun density is 1410 kg/m^3. Assuming human flesh is comparable to insect flesh, it's not a density issue.

I don't know; intuitively it doesn't seem like all the galaxy's mass equals a firefly that big. Corrections are welcome.

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Re: What-If 0151: "Sun Bug"

Postby Zohar » Tue Jul 19, 2016 7:53 pm UTC

Wolfram Alpha puts the Milky Way's mass at 6*10^42kg. Google suggests a firefly weighs about 11mg, so 11*1.6*10^47mg=1.76*10^42kg, which is around half (OK, quarter according to Wolfram's estimate) as much as the Milky Way.
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Re: What-If 0151: "Sun Bug"

Postby Soupspoon » Tue Jul 19, 2016 8:26 pm UTC

Hmm, how about arranging the fireflies into a Dyson Sphere, illuminating the centre. Each member scaled up for periodicity of 24 hours (around a centrally static Earth), although that would create a sky-segment of brightness, not a circular spot. Unless you accumulate a Sol's-worth of Apparent Magnitude only in a narrow swathe of the ecliptic area (use other insects or Space Spiders for as much of the rest of the structural sphere as necessary) and with other, more mobile, insects shining less brightly out we might be able to create a decent analogue of either geocentric or even heliocentric universe, depending upon swarming behaviour, that stands up well to scrutiny, at least before the invention of the telescope and spectrometer... (Not that they'd know that they were supposed to see Helium lines in the spectra, and given theologies regarding Sun-rolling giant dung-beetle gods in a significant subset of our own ancestral histories, it's no stranger a truth than an actual belief.)

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Re: What-If 0151: "Sun Bug"

Postby Flumble » Tue Jul 19, 2016 9:07 pm UTC

The Real WTF: there's no mention of Firefly at all. Has Randall lost his mind?

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Re: What-If 0151: "Sun Bug"

Postby rpgamer » Wed Jul 20, 2016 4:23 am UTC

Sun Bug looks like a good challenge for Sun Spider

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Re: What-If 0151: "Sun Bug"

Postby Echo244 » Wed Jul 20, 2016 8:50 am UTC

Flumble wrote:The Real WTF: there's no mention of Firefly at all. Has Randall lost his mind?


Possibly, it's certainly highly open to a comparison with the illumination provided by Serenity's main engine, but... I dunno, I think he's just... let it go.

My coat is still kind of brown. But it's quite a few years old, now.

I'm also slightly disappointed that he's not compared the Sun to other types of bioluminescence. There's a beautiful recent David Attenborough documentary that's been on TV recently - "Life that glows"? - that features all sorts of other sources of light. Including some stunning footage of dolphins swimming through a bioluminescent sea...
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Re: What-If 0151: "Sun Bug"

Postby Glib » Wed Jul 20, 2016 9:18 am UTC

Why would you want to match Sun's Luminocity, instead of asked visual brightness?

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Re: What-If 0151: "Sun Bug"

Postby Eternal Density » Wed Jul 20, 2016 10:05 am UTC

This one was pretty amusing, as well as interesting.
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Re: What-If 0151: "Sun Bug"

Postby teelo » Wed Jul 20, 2016 11:26 am UTC

Flumble wrote:The Real WTF: there's no mention of Firefly at all. Has Randall lost his mind?

I, too, was disappointed by the lack of this reference.

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Re: What-If 0151: "Sun Bug"

Postby cellocgw » Wed Jul 20, 2016 12:48 pm UTC

The part about needing 3E31 fireflies certainly brings back memories of a mole of moles. We've got approximately fifty million moles of fireflies.

Now, quoting same reference,

An eastern mole (Scalopus aquaticus) weighs about 75 grams, which means a mole of moles weighs
(6.022×10^23)×75g≈4.52×10^22kg


If one believes answers.com, a firefly runs 20 grams. Clearly the total firefly mass makes the mole of moles look like a dust spec by comparison.
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Re: What-If 0151: "Sun Bug"

Postby bhwrice » Wed Jul 20, 2016 2:24 pm UTC

What was that "8 ball, corner pocket." reference all about?

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Re: What-If 0151: "Sun Bug"

Postby Stardust0 » Wed Jul 20, 2016 3:03 pm UTC

How did firefly come to have the ability to emit light? Also why are there species that can do that? It seems to me that it would make them more visible to predators.

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Re: What-If 0151: "Sun Bug"

Postby cellocgw » Wed Jul 20, 2016 3:50 pm UTC

bhwrice wrote:What was that "8 ball, corner pocket." reference all about?


Well, an 8-ball is black.

Or maybe it's a sneaky quote from one of my favorite pins .
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Re: What-If 0151: "Sun Bug"

Postby tsarna » Wed Jul 20, 2016 4:00 pm UTC

I was disappointed that this one seemed to miss the next step. Having determined that a single big firefly of that size is too massive, collapsing into a black hole, the next question is can a smaller large firefly (or mass of fireflies) be made to collapse into a star of equivalent brighness to the sun? (A sort of bug-based version of what happens to Jupiter in 2010: Odyssey Two)

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Re: What-If 0151: "Sun Bug"

Postby SDK » Wed Jul 20, 2016 4:01 pm UTC

Stardust0 wrote:How did firefly come to have the ability to emit light? Also why are there species that can do that? It seems to me that it would make them more visible to predators.

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Re: What-If 0151: "Sun Bug"

Postby Jorpho » Wed Jul 20, 2016 4:56 pm UTC

I can't seem to find any good linkage about these "headlight bugs", which I guess explains why Randall didn't include any.

EDIT: Ohh, headlight beetle.
https://naturecloseups.com/posts/headlight-beetle
https://en.wikipedia.org/wiki/Pyrophorus_nyctophanus

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Re: What-If 0151: "Sun Bug"

Postby rmsgrey » Wed Jul 20, 2016 6:35 pm UTC

SDK wrote:
Stardust0 wrote:How did firefly come to have the ability to emit light? Also why are there species that can do that? It seems to me that it would make them more visible to predators.

The only thing more important than not being eaten is sex.


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Re: What-If 0151: "Sun Bug"

Postby gmalivuk » Wed Jul 20, 2016 9:06 pm UTC

Glib wrote:Why would you want to match Sun's Luminocity, instead of asked visual brightness?
Lumens are a measure of visual brightness.
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Re: What-If 0151: "Sun Bug"

Postby niauropsaka » Wed Jul 20, 2016 9:43 pm UTC

I kept thinking there had to be a whopper of a math error somewhere in this one.

If a bunch of normal sized fireflies as bright as Sol at a mass close to that of Jupiter, then surely one huge firefly of equivalent brightness is not going to be half the mass of the galaxy.

Wait. Randall is defining brightness of output according to two-dimensional surface area. And many fireflies have far more surface area than one big firefly.

But the bioluminescent layer still exists in three dimensions. If you scale up a firefly, with its mass increasing proportionally to its volume, its bioluminescent layer presumably does not default to remaining the same thickness.

I'm imagining the curve of increased output to run closer to the increase in mass of bioluminescent organs than to the increase in surface area. Am I wrong?

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Re: What-If 0151: "Sun Bug"

Postby DaveMcW » Thu Jul 21, 2016 1:13 am UTC

niauropsaka wrote:I'm imagining the curve of increased output to run closer to the increase in mass of bioluminescent organs than to the increase in surface area. Am I wrong?


As Randall metioned, there are 2 options.

1. "Arranging the fireflies in a hollow sphere, with their lanterns pointing outward." This would would scale linearly with bioluminescent mass. Also, you would want to point them inward, since the sphere is the size of the solar system.

2. "To make thing simpler, we could imagine a single giant firefly." The irony is that this is not simpler at all. Applying the square-cube law to living organisms always leads to unhealthy outcomes.

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Re: What-If 0151: "Sun Bug"

Postby Soupspoon » Thu Jul 21, 2016 2:24 am UTC

DaveMcW wrote:Applying the square-cube law to living organisms always leads to unhealthy outcomes.

And usually that's to the residents of Tokyo...

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Re: What-If 0151: "Sun Bug"

Postby 5th Earth » Thu Jul 21, 2016 2:04 pm UTC

For some reason when I first loaded this article, all the numbers in scientific notation were rendered as "[Math Execution Error]" or something like that. I can't remember exactly because it fixed itself on reloading.

I actually like the bugged version better; the juxtaposition of claiming that the numbers weren't that bad, and then having all of them replaced with errors, was hilarious and I almost thought deliberate.
It seemed like a good idea at the time.

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Re: What-If 0151: "Sun Bug"

Postby The_Alchemist » Thu Jul 21, 2016 6:21 pm UTC

DaveMcW wrote:
niauropsaka wrote:I'm imagining the curve of increased output to run closer to the increase in mass of bioluminescent organs than to the increase in surface area. Am I wrong?


As Randall mentioned, there are 2 options.

1. "Arranging the fireflies in a hollow sphere, with their lanterns pointing outward." This would would scale linearly with bioluminescent mass. Also, you would want to point them inward, since the sphere is the size of the solar system.

2. "To make thing simpler, we could imagine a single giant firefly." The irony is that this is not simpler at all. Applying the square-cube law to living organisms always leads to unhealthy outcomes.


I was disappointed that he didn't run through option 1. I wanted to see how big the sphere would be.

That said, I did chuckle quite a bit in this one.

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Re: What-If 0151: "Sun Bug"

Postby Mikeski » Thu Jul 21, 2016 6:34 pm UTC

5th Earth wrote:For some reason when I first loaded this article, all the numbers in scientific notation were rendered as "[Math Execution Error]" or something like that. I can't remember exactly because it fixed itself on reloading.

I actually like the bugged version better; the juxtaposition of claiming that the numbers weren't that bad, and then having all of them replaced with errors, was hilarious and I almost thought deliberate.

Especially with the mouseover text to the first picture: There are two numbers: "zero" and "anything that overflows your data type."

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Re: What-If 0151: "Sun Bug"

Postby mathmannix » Thu Jul 21, 2016 7:54 pm UTC

wouldn't "simple division" indicate it would take 6.3 x 1031 fireflies?
3.8E31 / 0.0006 = ?
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Re: What-If 0151: "Sun Bug"

Postby gmalivuk » Thu Jul 21, 2016 9:33 pm UTC

The_Alchemist wrote:
DaveMcW wrote:
niauropsaka wrote:I'm imagining the curve of increased output to run closer to the increase in mass of bioluminescent organs than to the increase in surface area. Am I wrong?


As Randall mentioned, there are 2 options.

1. "Arranging the fireflies in a hollow sphere, with their lanterns pointing outward." This would would scale linearly with bioluminescent mass. Also, you would want to point them inward, since the sphere is the size of the solar system.

2. "To make thing simpler, we could imagine a single giant firefly." The irony is that this is not simpler at all. Applying the square-cube law to living organisms always leads to unhealthy outcomes.


I was disappointed that he didn't run through option 1. I wanted to see how big the sphere would be.
If a firefly's cross-sectional area is about 10mm2, 3e31 of them would enclose a sphere with a radius of 32.7AU.
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Re: What-If 0151: "Sun Bug"

Postby ps.02 » Fri Jul 22, 2016 3:50 am UTC

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Re: What-If 0151: "Sun Bug"

Postby pogrmman » Fri Jul 22, 2016 4:36 pm UTC

cellocgw wrote:If one believes answers.com, a firefly runs 20 grams. Clearly the total firefly mass makes the mole of moles look like a dust spec by comparison.



20 grams? No way is any firefly that heavy! 20mg is much closer. I think Atta queens, which are one of the largest insects around here are around 25g (scratch that, it's actually closer to 40g {according to a paper by Mintzer and Vinson in the Journal of the New York Etyomological Society - I never weighed the queens I caught, so this is the best I could find} -- even so, they are still so much larger than fireflies that my point still stands). Most of the fireflies here are smaller than the head of an A. texana queen!

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Re: What-If 0151: "Sun Bug"

Postby keithl » Tue Jul 26, 2016 12:01 am UTC

Suggested AltWhatIf:

Randall mentions an enormous firefly immediately collapsing into a black hole, but how about making a black hole as luminous as the Sun? How many fireflies would that take?

Hawking radiation power is inversely proportional to the square of the mass: 3.562e32 W-kg2. To make a measly 3.84E26 W like our Sun, the hole would weigh 968 kilograms. We could make that with 88 billion 11 milligram fireflies. Piece of cake.

Although the question posed does not say how long our firefly light source should remain in operation, this black hole would emit gamma rays and evaporate in 75 nanoseconds, getting ever brighter before the final emission of Planck scale photons. That is not as long as one Standard Firefly Flash, and it is very difficult to read by gamma ray light. One Planck scale photon can ruin your whole day.

If we fed the Cosmic Firefly Trap with 3.84e26/(3e82) kg/s or 4.2 million tonnes of fireflies per second, straight towards the hole so they do not form an accretion disk, we can maintain luminosity. If the outermost opaque shell of infalling incandescent firefly plasma is 700,000 km radius, like the Sun, it will emit nice 5800K black body radiation, just like Mother Nature makes.

The Earth produces about 1e11 tonnes of biomass per year. At 10% feed-to-firefly conversion rates, that might produce 300 tonnes of finished fireflies per second, so we would need 14,000 extra Earths devoted to firefly farming. Firefly farms in trillions of O'Neill habitats might be a better use of the solar system's limited mass.

We could feed "Scott(tm) Firefly Farm Fertilizer" (processed ammonia and methane from Neptune, perhaps) straight into the Cosmic Firefly Trap, bypassing the inefficient firefly farming process, but that might void the warranty. Voiding the warranty of a mechanism incorporating a black hole is Not A Good Idea.

The infalling material will be much less dense than our Sun until it nears the event horizon, so the gravity will be much less. Since the Cosmic Firefly Trap weighs far less than the Sun, the planets would orbit it far more slowly. Endless summer (and winter) on Earth. Annual north-south migrations, where "annual" is thousands of generations. "Yes, I had a nice summer house in South America, but it was crushed under an ice sheet."

The rest, as my late friend Bob Forward would say, are "mere engineering details".

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Re: What-If 0151: "Sun Bug"

Postby DaveMcW » Wed Jul 27, 2016 12:56 am UTC

keithl wrote:To make a measly 3.84E26 W like our Sun, the hole would weigh 968 kilograms.


The Schwarzschild radius of a 968 kg black hole is 10-24 meters, which is millions of times smaller than a proton.

In Niagara Straw, we saw what happens when you try to squeeze 3000 tonnes of water through a 3.8 x 10-5 m2 straw.

Squeezing 4.2 million tonnes of plasma into a 10-48 m2 beam would be completely impractical. The beam itself would turn into a black hole that destroys the universe.

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Re: What-If 0151: "Sun Bug"

Postby keithl » Wed Jul 27, 2016 9:41 pm UTC

DaveMcW wrote:
keithl wrote:To make a measly 3.84E26 W like our Sun, the hole would weigh 968 kilograms.
The Schwarzschild radius of a 968 kg black hole is 10-24 meters, which is millions of times smaller than a proton.
In Niagara Straw, we saw what happens when you try to squeeze 3000 tonnes of water through a 3.8 x 10-5 m2 straw.

Indeed, it creates the power of a small star. Clearly inadequate power levels, we're aiming for largish G2-star power levels here.

DaveMcW wrote:Squeezing 4.2 million tonnes of plasma into a 10-48 m2 beam would be completely impractical. The beam itself would turn into a black hole that destroys the universe.

Has there ever been a "practical" WhatIf? I left out the "mere engineering details". If you want to get picky, use multiple beams, or feed multiple successive black holes. You might need a calculator with 3 digit exponents to compute the number of "multiple". Me, I don't look inside Cosmic Firefly Traps; opening one and voiding the warranty could disturb the finely tuned mechanism and destroy the universe, as your correct response suggests. Then where would we go for a refund?

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Re: What-If 0151: "Sun Bug"

Postby donbock » Mon Aug 15, 2016 8:07 pm UTC

The blink duty cycle of our solar lightning bugs will confound extrasolar astronomers in their search for exo-planets.

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Re: What-If 0151: "Sun Bug"

Postby SimonMoon5 » Thu Aug 18, 2016 4:14 pm UTC

But how many fireflies are there on the planet Earth? And how many planet Earths worth of fireflies would we need, in order to achieve the brightness of the Sun?

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Re: What-If 0151: "Sun Bug"

Postby Neil_Boekend » Thu Aug 18, 2016 5:43 pm UTC

I'd like to return this sun. It's buggy.
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Re: What-If 0151: "Sun Bug"

Postby edo » Thu Aug 25, 2016 7:08 pm UTC

tsarna wrote:I was disappointed that this one seemed to miss the next step. Having determined that a single big firefly of that size is too massive, collapsing into a black hole, the next question is can a smaller large firefly (or mass of fireflies) be made to collapse into a star of equivalent brighness to the sun? (A sort of bug-based version of what happens to Jupiter in 2010: Odyssey Two)


I went there as well. Seems Randall always wants to destroy the universe for some reason.

To answer your question, a Solar-Mass Firefly would release just about enough energy returning to hydrostatic equilibrium to ignite fusion. Because of the metalicity of the firefly, the fusion would "only" last about 1 billion years or so. (you also have the nasty problem of the energy released when fusion begins sterilizing the solar system until the outer layer cools)

EDIT:
A smaller still (~1/10 solar mass) would release 3 orders of magnitude less energy (funny how that works out), wouldn't ignite fusion, might even be survivable, and would glow for a long time. You may ask how long it will glow... well depends on what you mean by glow... there is always be some non-zero probability of a visible light photon emission. The object would technically be a Brown dwarf, and, as such, would take billions of years to cool (since it would be about the same size as Jupiter, so would cool at the same rate, but store 100x the initial energy)
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Re: What-If 0151: "Sun Bug"

Postby Mental Mouse » Sat Aug 27, 2016 1:35 pm UTC

Aside from destroying the universe, Randall seems to be getting into a slight rut with cosmic-scale masses of organic matter.

In that vein, it might work best to simply let a largish mass of fireflies collapse into an actual star -- it would be carbon- and oxygen-rich, so effectively further along in its "life-cycle" than our current star, but it still ought to last a while before it went nova.

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Re: What-If 0151: "Sun Bug"

Postby Neil_Boekend » Mon Aug 29, 2016 9:32 am UTC

edo wrote:A smaller still (~1/10 solar mass) would release 3 orders of magnitude less energy (funny how that works out), wouldn't ignite fusion, might even be survivable, and would glow for a long time. You may ask how long it will glow... well depends on what you mean by glow... there is always be some non-zero probability of a visible light photon emission. The object would technically be a Brown dwarf, and, as such, would take billions of years to cool (since it would be about the same size as Jupiter, so would cool at the same rate, but store 100x the initial energy)

It kinda weirds me out that objects don't really get bigger than Jupiter unless they have radiation pressure from fusion or become black holes. Add 1 Jupiter mass to Jupiter and the density almost doubles instead of the object getting significantly bigger. Add another Jupiter to the mix and the dang thing stays about the same size. Keep adding to get a total 13 Jupiter masses and you have an object with less than 2 times the volume of Jupiter. But freaking 13 times the mass!
And then you get to Brown Dwarfs. There the mass-volume graph is even flatter. Over 6 times the mass gets 1.10 to 1.15 times the volume. Eeek! That's 80 times the mass of Jupiter and less than 2.5 times the volume!
Rationally I know it's just how non-Coulombic-pressure matter behaves but it still weirds me out.
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Re: What-If 0151: "Sun Bug"

Postby ijuin » Tue Aug 30, 2016 4:36 am UTC

Interestingly, once you get above a certain mass (somewhere around the proton fusion threshold that divides brown dwarfs from red dwarfs), a non-fusing body starts getting SMALLER as you add more mass, because the gravitational pressure pulling inward rises faster than the electron degeneracy pressure pushing outward. Go far enough, and you get a white dwarf. Even farther, and it collapses into a neutron star or black hole.

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Re: What-If 0151: "Sun Bug"

Postby Neil_Boekend » Tue Aug 30, 2016 6:57 am UTC

But for that you'd need an object with an extremely high metalicity, right? Because too much hydrogen or helium would simply start fusing, generating the radiation pressure that blows up stars like air does with balloons, right?
Mikeski wrote:A "What If" update is never late. Nor is it early. It is posted precisely when it should be.

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Re: What-If 0151: "Sun Bug"

Postby ijuin » Tue Aug 30, 2016 2:39 pm UTC

Hydrogen fusion happens at around 80 Jupiters' mass, but helium fusion happens at just under 0.5 Solar masses, so you can get some compaction if you had low hydrogen but high helium.


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