Triangle for the entropic index q of non-extensive statistical mechanics observed by Voyager 1 in the distant heliosphere

Tsallis [Physica A 340 (2004) 1] identified a set of numbers, the “q-triplet” ≡{qstat, qsen, qrel}, for a system described by nonextensive statistical mechanics. The deviation of the q's from unity is a measure of the departure from thermodynamic equilibrium. We present observations of the q-triplets derived from two sets of daily averages of the magnetic field strength B observed by Voyager 1 in the solar wind near 40 AU during 1989 and near 85 AU during 2002, respectively. The results for 1989 do not differ significantly from those for 2002. We find qstat=1.75±0.06, qsen=-0.6±0.2, and qrel=3.8±0.3.