News- Scientists using the James Webb Space Telescope identified the earliest known supernova, observed just 730 million years after the universe’s birth.
About Supernova
A supernova is a massive and extremely bright explosion of a star, marking its violent end after it runs out of fuel or gains excessive mass.
Types of Supernova
Type 1: Supernova from single massive stars (Core-Collapse Supernova):
- It happens when a star at least five times the mass of the Sun runs out of nuclear fuel.
- While fuel burns in the core, it produces huge energy that makes the core very hot. This heat creates pressure that pushes outward and prevents collapse.
- A star is in balance between two opposite forces.
- The star’s gravity tries to squeeze the star into the smallest, tightest ball possible. But the nuclear fuel burning in the star’s core creates strong outward pressure. This outward push resists the inward squeeze of gravity.
- When the fuel ends, the pressure drops, gravity wins, and the star collapses, triggering the explosion.
Type 2: Supernova from white dwarfs in binary systems (Thermonuclear Runaway):
- It happen in systems where two stars orbit one another and at least one of those stars is an Earth-sized white dwarf. A white dwarf is what’s left after a star the size of our sun has run out of fuel.
- If a white dwarf collides with another white dwarf or pulls too much matter from a nearby star, it can exceed a critical mass limit called the Chandrasekhar limit, about 1.4 times the Sun’s mass.
- When this limit is crossed, runaway nuclear fusion ignites and completely destroys the star in a massive explosion, leaving no remnant behind.
Significance:
Supernovae distribute heavy elements across the galaxy, which are essential for the formation of new stars, planets, and complex matter.
They heat the interstellar medium and create powerful shock waves that shape the structure and evolution of galaxies.
These explosions leave behind neutron stars or black holes and produce high-energy radiation, helping scientists study extreme cosmic conditions.
