Voyager 1 and 2 Observations of a Change in the Nature of Magnetic Fluctuations in the VLISM with Increasing Distance from the Heliopause

Voyager 2 (V2) crossed the heliopause at 119.0 au on 2018 day 309, after which it observed compressive (longitudinal) magnetic field fluctuations along the average magnetic field direction in the very local interstellar medium (VLISM) at distances from 119.00 to 121.48 au and latitudes 322 to 324 S in heliographic inertial coordinates from 2018 day 309 to 2019 day 230. This result confirms the observations of longitudinal magnetic field fluctuations by Voyager 1 (V1) between 124.14 and 128.71 au at 346N (similar to 2-7 au upwind of the heliopause) from 2013 day 133 to 2014 day 235. V1 crossed the heliopause at 121.58 au and 345N on 2012 day 238. It came as a surprise to find it seemed that V1 observed transverse (Alfvenic) fluctuations of Bbetween 131.40 and 135.98 au at latitude 346-347N (similar to 10-14 au upwind of the heliopause) from 2015 day 145 to 2016 day 248. The most recent V1 observations show the possible presence of transverse fluctuations of Bin the VLISM from 141.44 to 146.01 au at 347-348N (similar to 20-24 au from the heliopause) between 2018 day 75 and 2019 day 178. Together, these observations show that longitudinal (compressive) magnetic field fluctuations are transmitted through the heliopause from the heliosheath into the VLISM, and are then converted into transverse (Alfvenic) fluctuations at similar to 130 au (similar to 8 au from the heliopause) that are observed out at 146 au (similar to 24 au from the heliopause).