Interstellar Inflow Speed, Temperature and Mach Number: IBEX and Ulysses Values Compared

This paper addresses a single question about the outer heliosphere: whether the two classic measurements of the interstellar wind blowing into the heliosphere agree, and what hangs on the difference. The calculation is performed from stated inputs drawn from published Voyager, IBEX and related measurements, with every step evaluated in the deposited script. The computed quantities are: ulys.v_kms = 23.2; ulys.T_K = 6300; ulys.cs_kms = 4.67; ulys.Mach = 4.968; ibex.v_kms = 25.4; ibex.T_K = 7500; ibex.cs_kms = 5.096; ibex.Mach = 4.985. The result is placed against the published values named in the text, and agreements and shortfalls are both reported. Where the arithmetic and the published values differ, the paper identifies which input is responsible rather than adjusting inputs to force agreement. This is a computed study based on published values; it is simulated, not measured, and it introduces no new observational data.