As far as I know stars are going supernova as a natural process. Can aliens trigger it artificially?

If this is possible then:

  1. How can I do this (what minimum technology and civilization development is needed; what tools or devices are needed)?
  2. How long this process will take (from "pushing button" till star exploding)?

My planet must be destroyed as an effect of that (destroying it is the only reason for triggering of this event) so, if it is "reasonable long period" how can I prevent planet's inhabitants from:

  • stopping this process (if this is possible) or
  • protecting themselves from these effects (this may be possible).
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    $\begingroup$ Of course. Anything that can happen naturally can be done artificially. Basically it's the same as saying magic doesn't exist. I think the question is somewhat equivalent with "how does a supernova happen". Have you done research? However, asking about minimum technology is nonsense/computer game logic/redundant. The minimal tech is whatever is required and then asking how long it takes, well, it just doesn't make sense. Perhaps try to reformulate that point $\endgroup$
    – Raditz_35
    Jul 5, 2018 at 15:31
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    $\begingroup$ @Raditz_35 - I think his question 1 is pretty clear. Asking how something would be done - details, tech involved - is neither nonsense nor redundant. The same goes for question 2. Given answers to question 1, asking how long it would take to make the star go nova artificially, makes perfect sense to me. $\endgroup$
    – user11864
    Jul 5, 2018 at 15:32
  • $\begingroup$ @Agapwlesu I would agree in a computer game. However we do not have a linear tech tree everybody has to follow in reality. My comment about q2 is specifically with the tech question in mind. If you allow any time, the minimum technology is whatever $\endgroup$
    – Raditz_35
    Jul 5, 2018 at 15:38
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    $\begingroup$ As for protecting themselves, There's a brilliant XKCD What If that actually answers that question $\endgroup$
    – Cort Ammon
    Jul 5, 2018 at 16:06
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    $\begingroup$ All of the answers come out to the same basic strategy: Move mass around to make a nearby star bigger. -- My question is, if you can move that much mass around (several hundreds of solar masses worth of matter), and are patient enough to wait the centuries it would take, why not take the shortcut of just continuously bombarding the target planet with asteroids? (Could be an interesting plot point as to why you can't just throw small rocks at the target itself, and must throw billions of large rocks at a nearby supergiant instead.) $\endgroup$
    – Ghedipunk
    Jul 5, 2018 at 17:59

4 Answers 4


According to the current models, the possible reasons for a supernova are thermal runaway or core collapse.

Thermal runaway is probably your best bet, and happens when the core of the star gets hot enough to start fusing carbon. This usually happens when a white dwarf steals enough mass from a companion.

Core collapse happens when nuclear fusion becomes unable to sustain the core against its own gravity. This usually happens in very large stars when the core gets enough iron to stop fusion. Stars cannot fuse anything heavier than iron, and so once you get to that phase fusion stops. This allows the core to collapse and either become a neutron star or a black hole, depending on the starting mass and composition. The process of collapsing also causes runaway fusion resulting in a supernova.

So how can the aliens do either of these things artificially?

The easy way is to get a large amount of energy into the center of the star which would trigger runaway fusion.

Peter F Hamilton used a Nova Bomb which used some kind of quantum fission effects to turn a jovian sized chunk of the star into energy.

Another way would be to deposit a quantity of anti-matter into the star's heart which would have the same effect.

Delivery would be difficult, but not impossible.

Both of these would require a level of technology way above what we have, but are not out of the realm of possibility.

As to Core collapse, this is a little harder, having to introduce a lot of iron into the star. The amount needed is called the Chandrasekhar mass, and is a lot of iron. If you could find an iron star and wormhole it into the core of an existing star that could do it, but the universe is far to young to have any iron stars yet.

You could transmute some of the stars mass into iron, but the energy needed would probably cause runaway fusion long before you could get the core to collapse.

The Charles Stross book Iron Sunrise used a temporal bomb/effect on a star to cause the core to age thousands of times faster than the rest of the star, causing it to fuse into iron very quickly, which collapsed the core and set off a nova.


This is the kind of problem for which the solution is exceedingly simply and straightfoward in theory, but too costly and impractical in practice.

For a supernova to happen, you need a dying star to have at around 60 to 130 solar masses. The simple, straightfoward solution is then bringing a dying star that is around 60-130 solar masses closer to your solar system.

The expensive part is bringing it into the system. It is possible - see this excellent answer from Thucydides on how to change the Moon's orbit, and scale it up to a very massive star instead of our Moon. You will probably need to juggle stars around - instead of moving a moon around, you will be moving stars across systems, maybe across galaxies. Your star system won't be the only one that will never be the same.

A safe distance from a supernova is around 50 to 100 light years. So you can park it, say, 40 light years away from your target.

Now, speed things up! Remember the process for bringing the star closer yout target? Bring a black hole too - one that is more massive than the star. Have the dying star orbit the black hole - the star will be in a timeframe where time passes faster than what a planet in a solar system like ours would experience. This will make it go boom faster.

Wait a few millenia, and enjoy as your enemies are fried to death :D

As for how the marks can survive or protect themselves from this... Supernovae are just too energetic. They wouldn't survive by hiding on the other side of the planet. Their best protection is stopping you from doing what you are doing.

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    $\begingroup$ You can also get a supernova with a white dwarf that gets over 1.4 solar masses. This might be a lot easier to move than a 60-130 solar mass star. $\endgroup$
    – AndyD273
    Jul 5, 2018 at 19:58
  • $\begingroup$ @AndyD273 But still a time-expense experience. Somehow, deeply in my physics and astronomy ignorance, I thought that the entire process can last like a... few hours or days, not a few millennia. $\endgroup$
    – trejder
    Jul 9, 2018 at 7:49

Remember When You Blew Up a Sun? https://tvtropes.org/pmwiki/pmwiki.php/Main/RememberWhenYouBlewUpASun

Jacob: Come on, Sam. It can't be any harder than blowing up a sun.

Sam: You know, you blow up one sun and suddenly everyone expects you to walk on water. (alien control panel lights up)

Sam: Next step, parting the Red Sea!

— Stargate SG-1, "Reckoning, Part 2"

In this episode of the TV show Stargate SG1, they refer to a prior episode where Carter (Samantha Carter) destroyed an alien armada threatening earth by causing a supernova. The Stargates in the show are devices which produce a wormhole through space to a different such device at some other place in the universe, allowing persons, matter and energy to move through.

In an earlier episode they determined (the hard way) that one stargate was on a planet in the process of falling into a black hole. Opening a channel to that stargate proved very dangerous.

In the "blew up a sun" episode, Sam Carter (aboard an alien vessel) dials the coordinates of the black hole stargate and then launches their own stargate into the sun. Then they clear the area. Stargates can evidently withstand the temperatures of a star. The black hole on the other side of the opened wormhole pulls away enough matter from the star to disrupt its fusion. This causes gravitational collapse and consequent supernova.

This is a fine SF way to cause a supernova: use your space transiting SF tech to suck away mass. How long it takes will depend on how much mass a given star must lose before its fusion cannot oppose its gravitational pull, and how quickly your SF space transiting tech can move stellar mass to some distant gravitationally avid object. In the show it took a couple of minutes, but they had to wrap things up fast.

  • $\begingroup$ Your answer is an contrary to what is said above (in both: answers, my comments and others comments) that the process of igniting a star to supernova can be very fast, given circumstances you described. I'm still very reluctant from the idea of technology being able to withstand both star energy and wormhole, but this is probably because I'm still thinking from "our" technology and development perspective. Certainly a valuable answer as for me and certainly an idea good enough to develop (or at least try). Thank you. $\endgroup$
    – trejder
    Jul 9, 2018 at 8:52
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    $\begingroup$ Relevant to the prospect of opening a portal inside a star and draining off matter: worldbuilding.stackexchange.com/questions/71310/…. The portal proposed on the linked question is from star to Earth. $\endgroup$
    – Willk
    Jul 9, 2018 at 11:53

One way a supernova happens is running out of nuclear fuel, I see no way how this could be done artificially.

The other way is if it is a binary system and one is a white dwarf you could force the other star to eject mass into the white dwarf.

Or if you are orbiting a white dwarf you could ship in huge amounts of matter and eject that into the star.


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