On the Stability of the Interstellar Wind through the Solar System

Abstract

As a follow-up of a recent study, we challenge the claim that the flow of interstellar helium through the solar system has changed substantially over the last decades. We argue that only the IBEX-Lo 2009-2010 measurements are discrepant with older consensus values. Then we show that the probability of the claimed variations of longitude and velocity are highly unlikely (about 1 per cent), in view of the absence of change in latitude and absence of change in the (flow velocity, flow longitude) relation, while random values would be expected. Finally, we report other independent studies showing the stability of Helium flow and the Hydrogen flow over the years 1996-2012, consistent with the seventies earlier determinations of the interstellar flow.