🌀 Parker Spiral: Solar-Wind Field Line, Winding Angle and Magnetic Connection (2D)

Top view of the solar equator in which the Sun turns while the solar wind flows straight out, so the magnetic field lines are wound into spirals. Set the wind speed, the distance of a spacecraft, the rotation period, the field strength and a fast stream, and see the winding angle, the field strength, the longitude on the Sun that the spacecraft is magnetically connected to, the travel time and where a fast stream catches a slow one. The winding angle, the field line length, the connection longitude and the stream collision distance are checked numerically, with four in-page numerical checks.