Tag: Alex Lobel

  • Science & Tech

    Raging storms of hot and cold gas

    New observations with the Space Telescope Imaging Spectrograph (STIS), Hubble’s high-precision and ultra-sensitive spectrometer, show that the warm chromosphere of Betelgeuse extends out to more than 50 times its radius in visible light, a size five times larger than the orbit of Neptune. (The chromosphere is an inner layer of a star’s atmosphere, between the…

    1–2 minutes
  • Science & Tech

    Betelgeuse’s chromosphere beats like a human heart

    For many years astronomers have known that the atmospheres of pulsating stars either expand or contract over time, but they have long puzzled over the question: “What physical mechanism drives these amazing dynamics?” Alex Lobel and Andrea Dupree of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge and Ronald Gilliland of the Space Telescope Institute…

    1–2 minutes