Solar wind interaction with comet 67P around perihelion - the formation of a cometosheath

Near perihelion, when comet 67P was most active, the Rosetta spacecraft resided inside the comet induced magnetosphere. The solar wind magnetic field was still present, but the solar wind ions were mostly gone, Rosetta was in the solar wind ion cavity. The solar wind was not completely gone though, there were sporadic occurrences of solar wind ions. Observations from this period shed light on the solar wind - comet interaction for a medium activity comet. Such a medium activity comet is the likely target of the Comet Interceptor mission so a better understanding of the environment will help planning plasma observations for that mission. Solar wind ions flowing consistently anti-sunward were seen,  indicating a fully developed cometosheath pushed closer to the nucleus. The speed of the solar wind in the cometosheath was typically around 200 km/s with a broad angular distribution. One-dimensional temperature estimates from direction integrated energy spectra indicate mostly little if any heating of the solar wind protons in the cometosheath. There are sporadic exceptions and we discuss whether these high proton temperature observations could be due to the interaction of the solar wind with the comet environment or is due to a coronal mass ejection or coronating interaction region. We compare the observations with hybrid model results.