Although it shines almost perfectly constantly, the Sun imperceptibly changes over time.
Each second, its core converts over 4 million tons of mass into energy.
Over time, the core grows, driving increases in energy output, luminosity, and — very slowly — size as well.
Today, the still-growing Sun is about 14% bigger than at birth.
After another ~5 billion years, it becomes a subgiant, expanding to double its current size.
About 2.5 billion years later, it swells into a red giant, fusing helium internally.
It will reach ~300 million km in diameter, engulfing Mercury, Venus, and possibly Earth, too.
But the Sun achieves true enormity upon completing its red giant phase.
After reaching the asymptotic giant branch, winds expel nearly all the remaining hydrogen.
Outflows, companions, and winds shape, shock, and collimate this stellar ejecta.
The matter reaches into the Oort cloud, illuminated as a preplanetary nebula.
The core contracts and heats up further, eventually ionizing the expelled material.
This shining planetary nebula phase lasts approximately 10,000 to 20,000 years.
Planetary nebulae grow over time, typically reaching ~5 light-years across.
Finally, the material cools, becoming neutral, invisible, and fading away.
Rejoining the interstellar medium, that expelled material contributes to future stellar and planetary generations.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.