Solar control on Jupiter's equatorial X‐ray emissions: 26–29 November 2003 XMM‐Newton observation

During Nov. 26–29, 2003 XMM‐Newton observed soft (0.2–2 keV) X‐ray emission from Jupiter for 69 hours. The low‐latitude X‐ray disk emission of Jupiter is observed to be almost uniform in intensity with brightness that is consistent with a solar‐photon driven process. The simultaneous light curves of Jovian equatorial X rays and solar X rays (measured by the TIMED/SEE and GOES satellites) show similar day‐to‐day variability. A large solar X‐ray flare occurring on the Jupiter‐facing side of the Sun is found to have a corresponding feature in the Jovian X rays. These results support the hypothesis that X‐ray emission from Jovian low‐latitudes are solar X rays scattered from the planet's upper atmosphere, and suggest that the Sun directly controls the non‐auroral X rays from Jupiter's disk. Our study also suggests that Jovian equatorial X rays can be used to monitor the solar X‐ray flare activity on the hemisphere of the Sun that is invisible to space weather satellites.