skip to main content

SciTech ConnectSciTech Connect

Title: Voyager 1 observations of the interstellar magnetic field and the transition from the heliosheath

Voyager 1 (V1) has been observing interstellar magnetic fields for more than one year beginning ≈2012/209, when V1 crossed a current sheet, a 'CS0' having the structure of a tangential discontinuity. The inclination of this current sheet is consistent with an interstellar magnetic field B draped on a blunt heliopause. Two other current sheets (sector boundaries) were observed at ≈2012/167 and ≈2011/276 with high inclinations (99° ± 10° and 89° ± 10°, respectively). From 2013.0 to ≈2013.6, the difference between the azimuthal angle λ of B from the Parker spiral angle at the latitude 34.°6 of V1 was λ – λ{sub P} = 22° ± 3° and the corresponding difference of the elevation angle δ was δ – δ{sub P} = 23° ± 8°. During 2012, the deviation from the Parker spiral angle was somewhat smaller. The interstellar magnetic field has a 'west to east polarity,' opposite to the direction of planetary motions. The magnitude of B varied smoothly in the range 0.38-0.59 nT with an average B = 0.486 ± 0.045 after 2012/237.7. The transition from heliosheath to interstellar magnetic fields is related to a 'two-step' increase in the cosmic ray intensity observed by V1 from ≈2012.30 to ≈2012.65.more » The first step increase began near the end of an unusual 'away-polarity' sector, and it reached a plateau when V1 moved into a 'toward-polarity' sector that ended at CS0. The second step increase began slowly after V1 crossed CS0, and it ended abruptly at 2012/237.728.« less
Authors:
 [1] ;  [2]
  1. NASA Goddard Space Flight Center, Code 673, Greenbelt, MD 20771 (United States)
  2. Institute for Astrophysics and Computational Sciences, Catholic University of America, Washington, DC 20064 (United States)
Publication Date:
OSTI Identifier:
22357214
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC RADIATION; HELIOSPHERE; INCLINATION; INTERSTELLAR MAGNETIC FIELDS; SOLAR WIND; SUN; VOYAGER SPACE PROBES