Horizonte Eventos Kerr
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Kerr Event Horizon Calculator is an online tool that calculates the event horizon radius of a rotating black hole, also known as a Kerr black hole. The event horizon is the boundary beyond which nothing, not even light, can escape the gravitational pull of the black hole. The formula used is r = GM/c² + √((GM/c²)²−a²), where G is the gravitational constant, M is the mass of the black hole, c is the speed of light, and a is the spin parameter of the black hole.
The formula works by combining the mass of the black hole and its spin rate to determine the event horizon radius. The spin parameter 'a' directly influences the calculation of the event horizon, making it different for rotating black holes compared to non-rotating ones. This reflects the complexity of the physics involved in Einstein's general theory of relativity.
This calculator is useful in contexts where one is studying or simulating astronomical phenomena related to rotating black holes. Real cases include the study of quasars, accretion disks around black holes, and the analysis of gravitational waves emitted during black hole mergers. Common precautions include ensuring that the input units are correct and understanding the limitations of the precision of the obtained values.
When using the Kerr Event Horizon Calculator, it is crucial to keep in mind that the results directly depend on the accuracy of the input data. Additionally, it is recommended to consult updated scientific sources to better understand the physical implications of the results and how they apply to different astronomical scenarios.
Frequently asked questions
What is the spin parameter 'a' in the formula?
The spin parameter 'a' is a measure of the black hole's rotation speed. It directly influences the calculation of the event horizon radius.
What units are used in the calculator?
The units used are standard for physical constants, such as the gravitational constant (G), the mass of the black hole (M) in kilograms, the speed of light (c) in meters per second, and the spin parameter (a) in meters.
Can I use this calculator for non-rotating black holes?
Yes, for non-rotating black holes, the spin parameter 'a' is zero. The calculator will provide the Schwarzschild radius as a result.
How does the accuracy of input data affect the results?
The accuracy of input data directly affects the accuracy of the results. Errors in input data will lead to errors in the calculated results.
Does the calculator consider quantum effects?
No, the calculator is based on Einstein's general theory of relativity and does not consider quantum effects. It is appropriate for macroscopic and gravitational scales.