Microwave emission of solar flares can be excited by energetic electrons through the gyrosynchrotron (GS) radiation. Thus, the microwave spectra contain valuable/unique information not only about energetic electrons accelerated during solar flares, but also about the underlying magnetic field and energy release process. The typical microwave spectra peak below or around, say, ~10 GHz, at which the spectral slope turns over from positive  — the optically thick regime — to […]

Comet 2I/Borisov was only the second interstellar object known to have entered the solar system. The highly eccentric, hyperbolic orbit of 2I/Borisov and its high inclination to the ecliptic plane demonstrated that the comet had an extrasolar system origin (e.g., Manzini et al. 2020). Polarimetric observations of this comet suggested a remarkably smooth, pristine coma with a high concentration of carbon monoxide, that had likely never interacted with the solar […]