approximately what core temperature is required before hydrogen fusion can begin in a star?
In order for hydrogen fusion to begin in a star, a specific core temperature, known as the ignition temperature, needs to be reached. This temperature is quite high due to the immense pressure and density in the stellar core.
The core temperature required for hydrogen fusion to start in a star depends on various factors, such as the mass and composition of the star. However, as a general rule of thumb, the core temperature needs to exceed about 10 million Kelvin (K) for hydrogen fusion to initiate.
At these incredibly high temperatures, hydrogen atoms in the star’s core collide with each other with enough energy to overcome their mutual electrostatic repulsion. This collision process, known as nuclear fusion, converts hydrogen atoms into helium atoms, releasing an enormous amount of energy in the form of light and heat.
Once hydrogen fusion begins, it generates a substantial amount of energy, providing the necessary pressure to balance the inward gravitational force acting on the star. This balance between gravity and pressure is what keeps a star stable and allows it to shine for billions of years.
It’s important to note that the core temperature needed for hydrogen fusion can vary depending on the star’s mass. Higher-mass stars have higher core temperatures, while lower-mass stars have lower core temperatures. Nevertheless, the rough estimate of around 10 million Kelvin serves as a reference for the minimum temperature required for hydrogen fusion to occur in most stars.