Soon after the sun sets on winter nights, if you live in the northern hemisphere you can look into the sky and find the Orion constellation near the eastern horizon. Astrophysicist Sarafina El-Badry Nance has always been drawn to a particular star in Orion: Betelgeuse, a red supergiant nearing the end of it's life on the hunter's left shoulder. But what stages of life did Betelgeuse — or any star — go through before it reached this moment? Regina G. Barber talks to Sarafina about three winter constellations, and journey through the life cycle of a star. Curious about the night sky? Email us at shortwave@npr.org — we'd love to hear from you!