UNI-MB - logo
UMNIK - logo
 
E-viri
Celotno besedilo
Recenzirano Odprti dostop
  • Hubble Detects the Start of...
    Simon, Amy A.; Nicholson, Philip D.; Tiscareno, Matthew S.; Showalter, Mark R.; McDonald, Troy

    Geophysical research letters, 16 February 2023, Letnik: 50, Številka: 3
    Journal Article

    Saturn’s ring spokes typically appear over an 8-year duration centered on equinox. Hubble Space Telescope observations in 2021 indicate the beginning of a new spoke season as Saturn approaches equinox in 2025. The spokes show increased contrast and longevity in 2022, persisting for up to eleven hours. The spokes are visible from UV to near-IR and are slightly bluer (i.e., less red) than the rings, but we find no significant wavelength dependence in the spectral contrast, which approximates their optical depth). Spoke rotation rates are between 606 and 626 minutes, consistent with either Keplerian rotation or possibly the variable rotation rate of Saturn’s kilometric radiation (SKR). Spoke activity is expected to increase over the next several years.