How Do Stars Become So Huge?

TLDRStars are massive spheres of hydrogen and helium undergoing nuclear fusion. They grow in size when they start fusing heavier elements and reach a fragile balance between gravity and radiation pressure. The largest known stars, red supergiants and hypergiants, can expand to billions of kilometers in diameter. Determining a star's size requires measuring its angular diameter and distance, which can be challenging due to their immense distances and interstellar radiation. Parallax and other indirect methods are used to estimate distances, but they are limited to nearby stars. The largest star in the universe is still unknown.

Key insights

🌟Stars are massive spheres of hydrogen and helium in a plasma state undergoing nuclear fusion.

⭐️Stars grow in size when they start fusing heavier elements and reach a fragile balance between gravity and radiation pressure.

🔆The largest known stars, red supergiants and hypergiants, can expand to billions of kilometers in diameter.

🌌Measuring a star's size requires determining its angular diameter and distance, which can be challenging due to their immense distances and interstellar radiation.

❓The largest star in the universe is still unknown due to limited measurements and the vastness of space.

Q&A

How do stars grow in size?

—Stars grow in size when they start fusing heavier elements and reach a delicate balance between gravity and radiation pressure.

What are the largest known stars?

—The largest known stars are red supergiants and hypergiants, which can expand to billions of kilometers in diameter.

How do we measure the size of stars?

—Measuring the size of stars involves determining their angular diameter and distance, which can be challenging due to their immense distances and interstellar radiation.

What is the largest star in the universe?

—The largest star in the universe is still unknown due to limited measurements and the vastness of space.

Why is it difficult to measure the size of stars?

—It is difficult to measure the size of stars due to their immense distances, interstellar radiation, and the limitations of current observational techniques.

Timestamped Summary

00:03Stars are massive spheres of hydrogen and helium undergoing nuclear fusion.

03:00Stars grow in size when they start fusing heavier elements and reach a delicate balance between gravity and radiation pressure.

07:34The largest known stars, red supergiants and hypergiants, can expand to billions of kilometers in diameter.

12:28Measuring a star's size requires determining its angular diameter and distance, which can be challenging due to their immense distances and interstellar radiation.

12:56The largest star in the universe is still unknown due to limited measurements and the vastness of space.