How near can we be to a black hole?

[Airbrush]

Does anyone know if a stellar-sized black hole could be located very near us? Is it possible one could be closer than 4 light years, but since they are hard to detect, we simply don't know? Or are we fairly certain there are none nearby?

[EWyatt]

Does anyone know if a stellar-sized black hole could be located very near us? Is it possible one could be closer than 4 light years, but since they are hard to detect, we simply don't know? Or are we fairly certain there are none nearby?

 

I would think that if there were a black hole within 4 light years, astronomers would have noticed the effects a black hole produces - the diffraction of light from other stars, gravity effects on nearby objects that are unseen, and the like.

[Schrödinger's hat]

Does anyone know if a stellar-sized black hole could be located very near us? Is it possible one could be closer than 4 light years, but since they are hard to detect, we simply don't know? Or are we fairly certain there are none nearby?

 

 

I would think that if there were a black hole within 4 light years, astronomers would have noticed the effects a black hole produces - the diffraction of light from other stars, gravity effects on nearby objects that are unseen, and the like.

 

There's always the chance that there's one that never passed in front of another star while anyone was looking, and that it has nothing left to accrete (and thus emit x-rays).

I can't seem to find any info after a brief search, but a very poorly informed guess would be that the chances that there's one closer than 10ly are extremely slim.

[CaptainPanic]

I think it's safe to assume that by now we've looked in every direction possible through our telescopes... and there are stars everywhere.

 

If there were a black hole very near us, we would have noticed a Gravitational Lens. And since we haven't found this, I guess it is safe to assume that there is no black hole within 4 light years... or at least not one of stellar size.