Calculating Weight and mass of entire black hole

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hyunxu
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Its pretty tough to calculate the entire mass and weight of entire black hole.But how we will give a approximate value? How we will calculate its mass and weight?

Could you list some stuffs that caught into the black hole?

Has any scientist ever visited a black hole and collected data on it?

Do each black hole have their own name?
 
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hyunxu said:
Could you list sone stuffs that caught into the black hole.

how about you do some reading and YOU list some things that might get drawn into a black hole

hyunxu said:
ANY SCIENTIST HAVE VISITED BLACK HOLE AND CREATED A RECORD?

what do you think would be the answer to that and why ?
hyunxu said:
Do each black hole have their own name?
some have namesDave
 
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hyunxu said:
But how we will give a approximate value? How we will calculate its mass and weight?

The easiest way is to measure the orbital period of objects that are in orbit of the black hole, a relatively straightforward calculation depending on what method you are using to measure the object with. Alternatively you could use General Relativity if you observe a gravitational lensing effect, but that is much, much harder to calculate.

hyunxu said:
ANY SCIENTIST HAVE VISITED BLACK HOLE AND CREATED A RECORD?

No. The nearest black hole is hundreds of light years from Earth if my memory serves. No one has even been outside of the solar system yet. Heck, we haven't even been to another planet yet.
 
The easiest way is to measure the orbital period of objects that are in orbit of the black hole, ---> do black holes have orbits?
 
hyunxu said:
The easiest way is to measure the orbital period of objects that are in orbit of the black hole, ---> do black holes have orbits?

Certainly. We could replace the Sun with a 1-solar mass black hole and the planets would continue on their merry way in their present orbits.
 
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hyunxu said:
The easiest way is to measure the orbital period of objects that are in orbit of the black hole, ---> do black holes have orbits?
Pretty much everything in space is orbiting something or has something orbiting it. Watching stars orbit something invisible is one of the only ways to know a black hole is there!
 
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hyunxu said:
The easiest way is to measure the orbital period of objects that are in orbit of the black hole, ---> do black holes have orbits?

You might find this web page of interest-
http://www.galacticcenter.astro.ucla.edu/animations.html
 
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stevebd1 said:
You might find this web page of interest-
http://www.galacticcenter.astro.ucla.edu/animations.html
Thank you so much
 
Drakkith said:
on their merry way

No so merry for us!

hyunxu said:
weight of entire black hole

Weight doesn't really have meaning in this context.

BoB
 
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rbelli1 said:
No so merry for us!
Weight doesn't really have meaning in this context.

BoB
Quite true, but (Keplerian) mass certainly does and is the usual meaning of "weight" when discussing astronomical objects.
 
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JMz said:
Quite true, but (Keplerian) mass certainly does and is the usual meaning of "weight" when discussing astronomical objects.

The OP specifically called out both mass and weight:

hyunxu said:
How we will calculate its mass and weight?

BoB
 
rbelli1 said:
The OP specifically called out both mass and weight:
BoB
Good point!