An #OTD thread from last year about Henrietta Swan Leavitt, and an important tool for measuring cosmic distances. 🧪 🔭 👩🔬
@mcnees.bsky.socialAstronomer Henrietta Swan Leavitt was born #OTD in 1868. She established the period-luminosity relation for Cepheid variable stars, an essential tool for understanding the scale of our Universe. 🧪 👩🔬 🔭
Image: Harvard-Smithsonian Center for Astrophysics
