I was just reading the comic book adaptation of Rogue One: A Star Wars Story, and this line by Chirrut Îmwe caught my attention:

Comic book frame from "Rogue One" with Jyn and Cassian walking through a crowded street towards the viewer.  In the background Chirrut Imwe faces them and say "The strongest stars have hearts of Kyber." Without looking back, Cassian says to Jyn "Ignore them.  This way."

The strongest stars have hearts of kyber.

This line is exactly the same as in the original film.

What does Chirrut mean? He can't be speaking about the Death Star, which used them as fuel, because there is no way for him to know about that (unless the Force told him and he forgot to mention it to others).

He could be speaking about the lighsabers, or maybe Jyn herself - this appears to be what countless speculations on the Internet say. Is there a more canon explanation, or maybe something that was said behind the scenes?

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    Are you sure he doesn't mean "stars" literally? Perhaps kyber crystals are created inside certain stars like heavier chemical elements are.
    – jwodder
    Commented Jun 4, 2017 at 14:05
  • Could be - but then what does "strongest" mean? And even Star Wars can't bend physics enough to make stars have a crystalline core. Commented Jun 4, 2017 at 14:08
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    I agree with jwodder. I always took the line as kyber crystals were created in cores of stars, too. And not just any stars, but the strongest in terms of size, mass or luminosity.
    – Essen
    Commented Jun 4, 2017 at 16:20
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    @Gallifreyan Why can't Star Wars, a completely fictional and fantastic universe, bend or completely break physics? Your name comes from a show that made the core of Earth out of spiders, that made the moon an egg for a dragon that somehow gained mass and then immediately upon hatching laid an egg of the exact same mass. Science Fantasy stories can do whatever they want with physics, be it crystal-cored stars, giant vacuum breathing asteroid-bound slugs, or mystical space magic.
    – Kevin Fee
    Commented Jun 6, 2017 at 23:56
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    also remember that Star Wars != Star Trek and Chirrut comes from a religious order. It is possible that 1) the composition of stars is not well studied in this galaxy long ago and far way and 2) Chirrut is repeating a legend / understanding he believes, not necessarily a scientific fact. His order reveres the Force and the kyber. It makes sense there would be psuedo-scientific legendarium built around those things, similar to flat-earth or geocentric teachings in the dark ages
    – NKCampbell
    Commented Jul 7, 2017 at 20:35

4 Answers 4


It can also mean something less literal. He says this after meeting Jyn who has the Kyber crystal around her neck. And both because of age and his post as a guardian of the whills it makes sense he knew Jedis, who used Kyber crystals in their sabers. Saying the strongest stars have hearts of Kyber can be more a connection to these strong people he has met in his life.

And look at Jyn when he first meets her here, still on the defensive, still on the road of her character development to become one of the heroes of Scarif. Telling her this was his way of telling her he can sense the strength in her.

That being said this is a galaxy far far away and we don't know how physics work in it so it might also be literal.


The suggestion appears to be that Kyber crystals are an exotic form of solid degenerate matter.

Astrophysical theory holds that White Dwarf stars, which begin as fluid masses of ordinary degenerate matter, eventually cool and crystallize into solid degenerate matter, in the process becoming Black Dwarves (theory also tells us that the earliest White Dwarves in the universe have not had time to cool to Black Dwarf stage.)

Degenerate matter is organized so that all electrons occupy densely-spaced, minimal, non-overlapping energy states normally caging an alarming amount of ordinary nucleonic matter. A teaspoonful of White Dwarf matter, you may have heard, weighs 5.5 tons. 99.995% of that mass though, is the ordinary-matter nucleons trapped in a degenerate-electron matrix. The electrons in that teaspoon weigh a mere 8 ounces.

In theory a degenerate substance could exist that's all electron matrix and no nucleons. That's because the electrons don't need the nucleons in order to form a degenerate gas, so long as half the electrons are positively charged antimatter positrons. A 50/50 mix of the two would tend to remain stable because the electrons and positrons are reluctant to approach one another any more closely than they already do.

It could even exist under ordinary conditions; For although created through terrific pressure, the degenerate matrix actually needs more energy to expand once formed than it can absorb from its environment. Its density, about 46 grams/cc, would be low enough you could handle it like an ordinary object merely twice as massive as platinum.

Such an all-electron degenerate matter crystal would have useful properties. You could channel enormous amounts of energy into it and out of it and use it as a perfectly efficient photon emitter. If you pushed it hard enough, it would implode into an instant antimatter explosion yielding 551-keV gamma rays, which could be used to pump an x-ray laser.

Where would you find Kyber? Most likely on a planet formed from a ruptured degenerate star. A crystallized star would tend to rupture if ordinary matter accumulated on its surface until the overburden pressure (the weight of the piled-up matter) triggered thermonuclear fusion in its core. This is called a Type 1a Supernova. Matter flees the scene at about 3% light-speed, so it takes some doing to slow it down and incorporate solid fragments in a planet!

In the universe of Star Wars, Kyber Crystals are more normally employed as force conduits than weapons fuel. That's how lightsabers work -- they guide power from what's basically a multi-megawatt-hour battery into a blade field. It's also a truism that only a living thing can wield a lightsaber, because Kyber crystals only respond to living users.

  • How does this explain that "The strongest stars have hearts of kyber" Kyber crystals don't exist in our universe? Why would Kyber crystals for from a ruptured degenerate star? Seems like a pretty big assumption to me
    – Edlothiad
    Commented Jul 30, 2017 at 22:18
  • Is there any evidence for this in canon sources?
    – Obsidia
    Commented Jul 30, 2017 at 22:35
  • Query for a quick check - I do not have my disks to hand to check - but in "Star Wars: The Clone Wars", doesn't the Droid who teaches the Younglings how to build a lightsaber activate one? (obviously Proxy and HK-47 use them, but are now presumed non-canon until Disney reintroduce them :¬( ) Commented Jan 22, 2019 at 12:27
  • Wait so do you need the force or at least a living creature to fire the Death Star? Darth Vader was all high and mighty about how it was just a technological marvel
    – Andrey
    Commented Jan 22, 2019 at 15:28

The line can be taken either literally or metaphorically, but I believe it was meant to be this way.

  1. The line is a literal reference to the Death "Star." "The strongest stars have hearts of kyber" - i.e., the Death Star is a powerful force that they must beware, and it is powered by kyber crystals.

  2. The line is a metaphorical reference to Jyn. Her father used to call her Stardust and she wears a kyber crystal from her parents around her neck; her "heart," as it were.

Chirrut is Force-sensitive, so it can be implied that he would know any of these facts through the Force - which is a bit of a cop-out, but it's the Force works. Even if he didn't explicitly know the details of the origin of Jyn's life, as an observer we can see that this line ties in to Chirrut sensing Jyn as being strong.


I would suggest what he meant was that the "Brightest" stars have hearts of Kyber meaning that they give off the most light, so to have a heart of Kyber means that you are a shining star. Stars float in the blackness of space, the Empire could be compared to the darkness, we can only find our way as long as we have the light.

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    Can you offer any evidence to back this up?
    – Valorum
    Commented Aug 10, 2019 at 16:44
  • Of course I can't it is all speculative as is with symbols things are often open to interpretation. Commented Aug 10, 2019 at 17:07
  • With a brand as popular as Star Wars, it's pretty common for elements of the films and scripts to be discussed by the crew, writers, in factbooks and making-of books, etc. I don't think it's true to say that symbolic things in Star Wars are 'all speculative'
    – Valorum
    Commented Aug 10, 2019 at 17:25

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