Contour map of the brightness of the HeI 58.4 nm emission line as calculated from our “modified cold model” for 2014-09-11. The (bigger) black dot at ecliptic longitude ~170° is the Sun. The scheme on the right of the figure depicts the geometry in the ecliptic plane, with the arrow representing the heliospheric flow direction; u = upwind direction; d = downwind direction; S = Sun; E = Earth (observer vantage point). The parameters used in this model are: downwind direction ecliptic lat. and long.: 75.4° and –5.2°; density, temperature, and velocity at infinity: 0.015 cm⁻³, 7440 K, and 25.4 km s⁻¹. Contour levels are separated by 0.5 Rayleighs (R) up to 5 R, then 5 R separation.