Deflection of Instellar Neutral Hydrogen
Using an absorption cell, we measured the Doppler shifts of the interstellar
hydrogen resonance glow to show the direction of the neutral hydrogen flow
as it enters the inner heliosphere. The neutral hydrogen flow is found to be
deflected relative to the helium flow by about 4 degrees. The most likely explanation
of this deflection is a distortion of the heliosphere under the action of an
ambient interstellar magnetic field. In this case, the helium flow vector and
the hydrogen flow vector constrain the direction of the magnetic field and act
as an interstellar magnetic compass.
Last Update: 1 September 2019
