How Might Sirius A Die?
Sirius A is a huge star (in the main sequence) right now. This is the longest, most stable period of a star's life. The star converts hydrogen to helium in its core, generating heat and light. The next phase Sirius will go through is the red super-giant phase. As nuclear fuel becomes depleted, the core contracts and the outer layers expand. Next the star will become a supernova. The core collapses in an instant. The repulsive electrical forces between in the core overcome the gravitational forces, causing a massive, short-lived explosion which blows away the star's outer layers. The next phase that Sirius will go through is the Neutron phase. It contracts tremendously into a small, dense about ten miles in diameter, 1.4 times the mass of the sun, with an extraordinarily strong magnetic field, and a rapid spin. These are the phases Sirius has to go through, leading to its death.
Main Sequence Star (Where it is right now)
Red Super-giant Star (Beginning of Sirius´s death)
When low and medium mass stars deplete their hydrogen fuel their core begins to collapse, significantly raising the temperature - by nearly an order of magnitude. The energy escaping from the core during this process pushes the outer part of the star outward, forming a red giant.
The star will remain a red giant until the core reaches a high enough temperature to begin fusion helium into carbon and oxygen. At this time the star shrinks down slightly into a yellow giant. |