What does determine the size of star?

Answer 1

Your question is unclear. Are you asking how does one calculate the size of a star, or what property of a star determines its size? I'm guessing the latter. In that case, the size of a star is directly related to its mass. The mass a star has collected when it formed, the larger the star will be.

Answer 2

It all depends on the mass of the black hole.

Edit: Maybe some more information about this relation can help. The relationship between the mass of a black hole and the radius of the event horizon (Think of the event horizon as a sphere around the singularity) is the following:

Rs = 2GM/c^2

With Rs the radius of the black hole, G the gravitational constant and c the speed of light in vaccuuum.

Answer 3

The Schwarzschild radius for a black hole - i.e., the radius of the event horizon - is directly proportional to the black hole's mass. It is approximately 2.95 km for every solar mass; so for example, for Sag. A*, which has about 4 million times the mass of our Sun, you can multiply 2.95 by 4 million. If you want the diameter, multiply the radius by 2.

Answer 4

I assume you mean the event horizon of a black hole. The diameter or radius of this event horizon is directly proportional to the black hole's mass. For example, for twice the mass, the diameter of the event horizon would also be twice as much.

Answer 5

3 parameters of the black hole: mass, spin, charge.

Answer 6

what determines the size of a magnetic field