ESA Science & Technology - Deflection of the Interstellar Medium

Publication date: 04 March 2005

Authors: Lallement, R., et al.

Journal: Science
Volume: 307
Page: 1449
Year: 2005

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.