Scientists Make Breakthrough in Understanding of the North Star, Polaris

Strategic Insights -

Scientists at Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array have made a significant discovery in their understanding of the North Star, also known as Polaris. The team, led by Nancy Remage Evans, used the CHARA Array to capture close-up images of Polaris, revealing large bright and dark spots on its surface that change over time. The goal of the investigation was to map the orbit of a close, faint companion that orbits Polaris every 30 years. The team successfully tracked the orbits of the two close companions and measured changes in the size of the bigger variable star as it pulsated.

Key Takeaways:

  • The CHARA Array revealed large bright and dark spots on the surface of Polaris that change over time.
  • The team successfully tracked the orbits of the two close companions and measured changes in the size of the bigger variable star as it pulsated.
  • The big variable star of the Polaris system has five times the mass of our own sun, with a diameter that is 46 times bigger.
  • The North Star is a multi-star system that appears as a single star to Earthbound visitors using the unaided eye.
  • The main star is a variable star, also known as a cepheid, which can be used to reliably measure distances throughout the universe.
  • The North Star "sits more or less directly above Earth's North Pole along our planet's rotational axis" and is a reliable way to find the direction of north.
  • The Earth's axis of rotation wobbles over the course of about 26,000 years, causing the celestial pole to change over time.

Statistics:

  • The big variable star of the Polaris system has a diameter that is 46 times bigger than our own sun.
  • The North Star is about 600,000 times smaller than the full moon in the sky.
  • The Earth's axis of rotation wobbles over the course of about 26,000 years.
  • The North Star "sits more or less directly above Earth's North Pole along our planet's rotational axis" at a distance that is negligible to astronomers.

Sources:

  • Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array news release (Aug. 20)
  • NASA primer on the North Star
  • [1] Insidehaltoncom The North Star has guided travellers in the Northern Hemisphere for so long now, it's become part of our lexicon - a metaphor for reliability.