Does that make the assumption that the nova's energy is distributed evenly? Because I believe there are gamma ray bursts that are quite directional, and can if pointed at us cause harm far further than that. (IANA astronomer...)
No, a gamma ray burst pointed at us within several thousand light years could cause a mass extinction event. There are a couple of candidates for mass extinctions which might have been GRBs. They are very rare though.
Still, it would be safer to get out of the thick part of the galaxy as soon as possible. Life in a galaxy risks many different hazards. I don't think we have ruled out magnetars nearby enough that a minor starquake would sterilize the whole solar system. Aggressive neighbors might want to use up our valuable Kuiper Belt objects on their own projects.
Maybe start by shifting the orbit of the whole solar system out-of-plane. (I guess that would be done by electromagnetically stimulating the sun to produce a polar jet for a few million years.) That provides our distant descendants another 100M years to alter the orbit further so as not to just plunge back in on the other side. But even without, the risk would grow back to our present level for only (say) 10M out of each 100M years, strictly an improvement.
Orbital plane maneuvers are infamously expensive in delta-V.
Spending the following 100M years increasing our galactic orbital radius might put us in the outskirts before crossing again, if we did not actually escape entirely.
We might also be able to put off by a few billion years the sun itself sterilizing the planet, using the same apparatus. We could only hope it would not be abused to destroy us itself.
Andromeda isn't due for another 4.5 Gy. Presumably its central black hole and ours will merge shortly thereafter, maybe sterilizing the whole galaxy? I am content to leave worrying about that to others.
I don’t know where they got that number from. It’s depending on a multitude of factors like, type of supernova and orientation of the supernova (like if we’re in line for a gamma ray burst)
*edit
For anyone interested in this topic I suggest Phil Plait’s book in the subject
I think 5 ly is the range for a supernova sterilizing the solar system if we are not so unlucky to be in a jet.
500 ly is supposed to be equivalent range for a magnetar quake. I think the nearest known magnetar is around 10x that. But even 1% of the radiation needed to sterilize the solar system would be pretty uncomfortable.
> Astronomers' current models of the evolution of binary systems cannot fully explain how the peculiar configuration of the Gaia BH1 system came about, because the original star that later became this black hole should have been at least 20 times more massive than our Sun. This means that it would have lived only a few million years. If both stars formed at the same time, this massive star would have rapidly become a supergiant, inflating and engulfing the other star before it had time to become a proper main-sequence star, burning hydrogen just like our own Sun.
> It's not entirely clear how the solar-mass star survived that episode, ending up an apparently normal star, as observations indicate. All theoretical models that allow for this survival predict that the solar-mass star should be in a much tighter orbit than is actually observed.
Should this last sentence actually read: "All theoretical models that allow for this survival predict that the solar-mass star should be in a much wider orbit than is actually observed."?
No, from the abstract of the paper "The orbital period, 185.6 days, is longer than that of any known stellar mass black hole binary. [...] How the system formed is uncertain. Common envelope evolution can only produce the system's wide orbit under extreme and likely unphysical assumptions"
See section 8.4 for details: https://arxiv.org/abs/2209.06833
But basically the idea is that they are assumed to have interacted in the past (based on the distance), and given that, all current models of such interactions would predict a very tight final orbit for the solar mass star.
The issue here is that I don't read spanish. I used a translator - google, actually. And I know painfully well that sometimes translations are clunky even when they are generally good. I don't have a lot of experience between Spanish and English, but I do with Norwegian-English, and those are both germanic languages and often translate decently.
But not always. Some things are just messed up. Some things don't translate word-for-word simply because folks express things differently.
So yeah, it might be weird in English. Might not be in Spanish, though.
They calculate that it is 1600 light years away. So, unless you were lighting your childhood campfires 1600 years ago, that light still has a little way to go.
For comparison, a star going supernova to harm earth has be to within 70 LY.