Tag: Cepheid variables

• How We Know the Distance to a Star: Climbing the Cosmic Distance Ladder One Rung at a TimeParallax, Cepheids and Type Ia supernovae form a three-rung ruler. We build each rung from the inverse-square law, find the distance to δ Cephei, and track how errors accumulate.PhysicsCosmologyHigh school / generalcosmologydistance measurementparallaxCepheid variablessupernovae~30 min