Black Hole - Understanding the Phenomenon & Its Significance | UPSC Notes

What exactly is a black hole?

• Black holes are essentially regions in space that possess such extreme density that they generate profound gravity wells. Beyond a certain threshold, even light cannot escape the intense gravitational pull of a black hole.
• Simply put, black holes are areas in space where a colossal amount of mass is compacted into an exceedingly small volume.

A star devours a planet in a single gulp:

• An intriguing event was reported where a dying star was consumed by a black hole. Initially, it was believed to be a gamma-ray burst from a collapsing star, but it proved to be different.
• Traditional gamma-ray bursts consist of a flood of high-energy photons rushing through space. They generally occur when a star explodes or when two objects collide.
• It's believed that most galaxies have black holes at their core. The burst originated from the center of a galaxy located four billion light-years away.
• Observations revealed that “The black hole was dormant until a star ventured too close, its gas got torn apart, and in the process, some of it got ejected.”
• Scientists have also discovered numerous planets with tight orbits that are destined to fall within the radius of red giants in the future.

Life cycle of stars:

• The life cycles of stars are closely tied to their masses. Small stars, like red dwarfs, can shine for trillions of years, while the largest stars explode a few million years after their formation.
• When stars similar to the sun begin to die after billions of years, they evolve into a category known as red giants. These stars expand hundreds of times in size, engulfing anything within their expanding boundaries.

Importance of this discovery:

• This discovery “offers a crucial piece of the puzzle in our understanding of the evolution and ultimate destiny of planetary systems,” including our own.
• It allows us to gain insights into astronomical events and the patterns governing the workings of galaxies and solar systems.