Thursday

Both Solar Orbiter and Parker Solar Probe (PSP) will take extensive measurements of the solar wind inside 1 AU, but they will not be the first: in the 1970s and 80s the Helios spacecraft made comprehensive in situ measurements of the solar wind. I will present recent work using a re-analysis of the Helios data showing three distinct categories of solar wind can be identified inside 0.8 AU. Using physical arguments each of these three categories can be associated with distinct solar sources (ie. coronal holes, active regions, and small transient structures). Although speculative, this provides a new tool that can be used in association with other methods to link the Sun to the heliosphere. I will finish by briefly discussing how in situ measurements from PSP and Solar Orbiter will be used to further understand sources of the solar wind.