Stellar Wind Densities at Exoplanet Orbits: Close-In Giants and a Young Solar Analogue

This paper examines wind number densities at exoplanet orbits for GJ 436 b, HD 209458 b, 51 Pegasi b and planets of a young Sun-like star, using published input values and transparent formulae throughout. The headline computed results are: density_GJ436b_cm-3 = 7222.22; density_HD209458b_cm-3 = 4811.82; density_young_0.1AU_cm-3 = 4.252e+04. Each quantity bearing on wind number densities at exoplanet orbits is derived in the deposited calculation script from the stated inputs, so the full chain from published value to conclusion for GJ 436 b, HD 209458 b, 51 Pegasi b and planets of a young Sun-like star can be audited and rescaled. The discussion of wind number densities at exoplanet orbits compares the outcomes with independent published estimates, identifies the input to which each result is most sensitive, and confines the conclusions to what the arithmetic supports. Where the computed values for GJ 436 b, HD 209458 b, 51 Pegasi b and planets of a young Sun-like star confirm earlier estimates, the confirmation is meaningful because no adjustable parameter was available to force agreement on wind number densities at exoplanet orbits; where they differ, the size and likely origin of the difference are stated directly.