After sunset on winter nights, those in the northern hemisphere can observe the Orion constellation near the eastern horizon. According to Greek mythology, Orion was a renowned hunter who, as one myth suggests, was banished to the sky for his boasts about his hunting prowess. With his two hunting dogs, he eternally chases Taurus the bull and the Pleiades sisters as a form of punishment.
In another myth, the goddess Artemis is said to have mistakenly killed Orion and placed his image among the stars. Orion is easily recognizable by the three aligned stars that form his belt.
Astrophysicist Sarafina El-Badry Nance finds particular interest in a star within Orion, known as Betelgeuse. This red supergiant, located on Orion’s left shoulder, is nearing the end of its life and will eventually explode as a supernova.
The Lifecycle of a Star
Birth of Stars: Stars originate within dust clouds scattered across galaxies. These regions, composed of gas and dust, eventually clump together due to gravity. Over time, they collapse under their own weight and form what is called a protostar, the early stage of a star. As these protostars develop, they begin to fuse hydrogen into helium, releasing energy that we perceive as starlight.
Main Sequence: Stars spend most of their lifespan in a stable phase, often referred to as middle age. During this period, they continue to burn hydrogen in their cores. The sun, for instance, is a middle-aged star and scientists predict it will burn hydrogen for about another five billion years.
End of Life: Once a star exhausts its hydrogen fuel for fusion, its core collapses. The outer layers expand and cool, transforming the star into a swollen form. Betelgeuse exemplifies a star nearing the end of its life, with an inevitable dramatic supernova explosion expected.
El-Badry Nance notes that while scientists cannot predict the exact timing of Betelgeuse’s explosion, it will be a spectacle visible from Earth.
“First and foremost: Everything changes. There’s nothing static in the universe, even if the timescales are longer than our own,” says El-Badry Nance. “Periods of turbulence and chaos can lead to something beautiful.”
If you’re curious about the night sky, you can reach out through email at [email protected]. Additionally, you can listen to more insights on Spotify, Apple Podcasts, and Google Podcasts. The episode was produced by Rachel Carlson, edited by Rebecca Ramirez, fact-checked by Brit Hanson, and audio-engineered by Ko Takasugi-Czernowin.