How to look at a black hole

[Jojo204]

Hi all,

just something to think about here. Let’s say Betelgeuse explodes within the next week. Woah pretty cool ok. Now it’s been a while and all the hyped died down. Let’s say it turns into a black hole. If we use our autoguiding scopes and align them then tell them to point to Betelgeuse, would we be ‘seeing’ a black hole? Pretty cool.

 

[Davey-T]

Supposing you had a powerful enough scope I don't think you can actually see them as all the stuff whizzing around them glows brightly in all sorts of wavelengths.

Dave

[Paul73]

I’m guessing that once the debris have settled there really wouldn’t be much to see. Gobbling nearby stars  is unlikely as the ex Betelgeuse doesn’t have any more mas than it started with, so no increase in overal gravity?...

There could be some interesting gravitational lensing effects on targets behind the black hole.

Paul

[vlaiv]

Small sized telescope - like we have now - same space picture just a star missing.

Much larger sized telescope - again the same.

Very very very large scope, one that can potentially resolve event horizon region, something like this:

Absolutely nothing in region defined by diameter of event horizon - with distinct gravitational lensing very near to "surface" of event horizon and just normal star field further away.

It would be the same image if somehow one managed to squeeze out all stars that were "behind" event horizon in region just outside of it. Here is diagram:

[Demonperformer]

Individual black holes would be fairly unimpressive. Black holes as part of a binary system are quite interesting, but mainly in the high energy wavelengths. If you want to check out a black hole, have a look at Cygnus X-1 (HD 226868 - that is actually the visual component mag @8.8) ... pretty unimpressive visually, huh?

[Jojo204]

Ah yes what I mean is that it would be cool cause you know you are looking at a black hole definitely, not probably,from your garden. 

[vlaiv]

Just now, Jojo204 said:

Ah yes what I mean is that it would be cool cause you know you are looking at a black hole definitely, not probably,from your garden. 

Got even cooler one

Point your scope to M87 and "observe" super massive black hole in action! Relativistic jet included!

[Jojo204]

Just now, vlaiv said:

Got even cooler one

Point your scope to M87 and "observe" super massive black hole in action! Relativistic jet included!

Sounds like this’ll keep me busy next few hours!