The scintillating tail of comet C/2020 F3 (Neowise)

Vol. 667
10. Planets and planetary systems

The scintillating tail of comet C/2020 F3 (Neowise)

Scintillation is a standard tool for studying the intervening ionized medium in the direction of radio sources, but it is usually associated with multi-parsec pathlengths. This study brings the tool home. The authors used LOFAR observations at 120-180 MHz to probe the ionized component of a comet. Over a four-hour interval, 3C 196, a serendipitously obscured radio galaxy, was passed by comet C/2020 F within about a half degree of the coma. The authors obtained high-cadence time series for dynamical spectra and scintillation power spectra throughout the transit. The scintillation indices are consistent with strong boundary turbulence where the tail meets the solar wind. Comet observations with LOFAR, and eventually SKA, should yield fundamental data for comparisons with models of plasma and hydrodynamic turbulence in strongly driven environments.