17214

The asymetric magnetosphere of Uranus is now approaching southern solstice comma gradually shifting from its equinox-to-solstice intermediate geometry. We propose to image the UV (H and H2) aurorae of Uranus with STIS and ACS instruments near next opposition with a two-fold objective. We first aim at investigating the current comma poorly known comma magnetospheric configuration in which a diversity of UV aurorae comma probing various acceleration mechanisms comma is expected to co-exist. The observations will be carefully scheduled to sample variable solar wind conditions and all planetary longitudes to asses the solar wind-magnetosphere interaction. The aurorae will then be accurately fitted by model auroral ovals to retrieve the position of the magnetic poles. This reference will then be used comma on the one hand to further constrain the inner rotation rate and the associated SIII longitude system and comma on the other hand to analyze planned coordinated observations of the planet by JWST in the NIR and by XMM-Newton at X-ray wavelengths.