The Life and Death of Stars: A Journey Through the Night Sky

As winter descends in the northern hemisphere, the night sky unveils the Orion constellation near the eastern horizon after sunset. Orion, known in Greek mythology as a legendary hunter, was cast into the stars as a result of his arrogance. He is said to eternally pursue Taurus the bull and the Pleiades sisters, always chasing but never catching.

One myth recounts that Artemis, the goddess of the hunt, was deceived into slaying Orion with her arrow, leading to his immortalization among the stars. Spotting Orion is easy by identifying the three stars that form his belt.

The Star Betelgeuse

Astrophysicist Sarafina El-Badry Nance has a particular interest in Betelgeuse, a significant star within Orion. This red supergiant, positioned on Orion’s left shoulder, is nearing the end of its life cycle, poised to become a supernova.

Birth of a Star

Stars are born in dusty clouds scattered across galaxies. “These regions attract gas and dust through gravity,” El-Badry Nance explains. “As these materials accumulate, pressure increases, leading to the formation of a protostar, which is essentially a developing star.”

As time passes, these protostars begin fusing hydrogen into helium at their cores, emitting energy as light, and thereby preventing collapse. This phase comprises the majority of a star’s lifespan, during which it remains stable. Our sun is currently in this middle-aged stage, with an expected hydrogen fusion life of about five billion more years.

The Death of a Star

Once a star’s hydrogen is exhausted, its core collapses, initiating its final life stage. The outer layers expand and cool, transforming it into a massive, bloated star. Betelgeuse serves as an example of this phase. Due to its size, its death will be dramatic, culminating in a supernova explosion.

The timing of Betelgeuse’s explosion remains uncertain, but when it occurs, its brilliance will be visible from Earth for a significant duration.

Lessons from the Stars

The lifecycle of stars imparts important lessons. “Change is constant,” El-Badry Nance reflects. “The universe is never static, though it may seem so to us due to the vast timescales involved. We all encounter periods of upheaval, yet these can yield new beauty.”

Have questions about the stars? Reach out to [email protected]. Listen to Short Wave on Spotify, Apple Podcasts, and Google Podcasts. Today’s episode was produced by Rachel Carlson, edited by Rebecca Ramirez, with fact-checking by Brit Hanson, and audio engineering by Ko Takasugi-Czernowin.