4 ms·

The numbers : Size : 10 x sun's mass. Distance : 1600 LY. Previous closest had been : ~5000 LY. Discovered by calculating the velocity of a rotati

The numbers : Size : 10 x sun's mass. Distance : 1600 LY. Previous closest had been : ~5000 LY. Discovered by calculating the velocity of a rotating run around it. For comparison, a star going supernova to harm earth has be to within 70 LY.

867-5309 4y ago
>For distance comparison, a star going supernova to harm earth has be to within 70 LY. what is that based on?
- Smashure 4y ago
  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
- pencilguin 4y ago
  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.
bilsbie 4y ago
Any risks of that within 70ly?
- ceejayoz 4y ago
  Not at the moment. IK Pegasi is the closest candidate, at about 2x that distance. Would be a hell of a show, though. https://en.wikipedia.org/wiki/Near-Earth_supernova https://en.wikipedia.org/wiki/Near-Earth_supernova
dtgriscom 4y ago
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...)
- colechristensen 4y ago
  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.
  - pencilguin 4y ago
    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.
dustingetz 4y ago
how wide is the event horizon and how close can a current gen spaceship get before being gravitationally bound?
- Hobert 4y ago
  About 1600LY...
derjames 4y ago
Schwarzschild radius ~28 km https://en.wikipedia.org/wiki/Gaia_BH1 https://en.wikipedia.org/wiki/Gaia_BH1
- sabujp 4y ago
  tx this is what i was looking for, also this agrees https://www.omnicalculator.com/physics/schwarzschild-radius https://www.omnicalculator.com/physics/schwarzschild-radius

867-5309 4y ago

>For distance comparison, a star going supernova to harm earth has be to within 70 LY. what is that based on?

Smashure 4y ago
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
pencilguin 4y ago
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.

bilsbie 4y ago

Any risks of that within 70ly?

ceejayoz 4y ago
Not at the moment. IK Pegasi is the closest candidate, at about 2x that distance. Would be a hell of a show, though. https://en.wikipedia.org/wiki/Near-Earth_supernova https://en.wikipedia.org/wiki/Near-Earth_supernova

dtgriscom 4y ago

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...)

colechristensen 4y ago
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.
- pencilguin 4y ago
  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.

dustingetz 4y ago

how wide is the event horizon and how close can a current gen spaceship get before being gravitationally bound?

Hobert 4y ago
About 1600LY...

derjames 4y ago

Schwarzschild radius ~28 km https://en.wikipedia.org/wiki/Gaia_BH1 https://en.wikipedia.org/wiki/Gaia_BH1

sabujp 4y ago
tx this is what i was looking for, also this agrees https://www.omnicalculator.com/physics/schwarzschild-radius https://www.omnicalculator.com/physics/schwarzschild-radius