Mass of Black Holes: Measuring the Unmeasurable?

[zero12104]

Sorry if this is in the wrong topic area but I'm really wondering this. Would there be any way to measure the mass of a black hole? This is a really interesting thing that I would like to know about. Thanks to anyone that helps!

 

[chroot]

Welcome to PF!

There are many ways to measure the mass, and some are deceptively simple.

A black hole of a given mass behaves gravitationally just like any other kind of object with the same mass.

All you need is to do is put a test mass -- say, 1 kg lump of metal -- into orbit around the hole. By observing the lump's orbit, you can calculate the black hole's mass.

You can also use what Nature gives you: stars. By watching the speeds at which stars orbit a suspected black hole, we can estimate the mass of that black hole.

- Warren

 

[zero12104]

Thank you vey much for that. I've been looking everywhere and now I finally know and I can ace my report! Thanks!