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Title: VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH

Abstract

Voyager 2 (V2) entered the heliosheath in 2007 August at roughly the same time solar minimum conditions were reaching the outer heliosphere. Soon after crossing the termination shock the solar wind density at Voyager decreased by a factor of two and the temperature decreased by a factor of three. At the beginning of 2011 the plasma density in the heliosheath began to increase and in mid-2012 it was up by more than a factor of two. The temperature rose by about 50% and the speed remained constant, although the flow direction continues to turn tailward. These changes may signal the end of solar minimum conditions at V2 in the heliosheath, although we do not understand why the speed did not decrease. The increased dynamic pressure has lead to an outward movement of the termination shock from its very compressed state at solar minimum.

Authors:
 [1];  [2]
  1. Kavli Center for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
  2. State Key Laboratory for Space Weather, Chinese Academy of Sciences, Beijing (China)
Publication Date:
OSTI Identifier:
22078459
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 759; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; HELIOSPHERE; PLASMA DENSITY; SIGNALS; SOLAR WIND; VOYAGER SPACE PROBES

Citation Formats

Richardson, J. D., and Wang, C., E-mail: jdr@space.mit.edu, E-mail: cw@spaceweather.ac.cn. VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH. United States: N. p., 2012. Web. doi:10.1088/2041-8205/759/1/L19.
Richardson, J. D., & Wang, C., E-mail: jdr@space.mit.edu, E-mail: cw@spaceweather.ac.cn. VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH. United States. doi:10.1088/2041-8205/759/1/L19.
Richardson, J. D., and Wang, C., E-mail: jdr@space.mit.edu, E-mail: cw@spaceweather.ac.cn. Thu . "VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH". United States. doi:10.1088/2041-8205/759/1/L19.
@article{osti_22078459,
title = {VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH},
author = {Richardson, J. D. and Wang, C., E-mail: jdr@space.mit.edu, E-mail: cw@spaceweather.ac.cn},
abstractNote = {Voyager 2 (V2) entered the heliosheath in 2007 August at roughly the same time solar minimum conditions were reaching the outer heliosphere. Soon after crossing the termination shock the solar wind density at Voyager decreased by a factor of two and the temperature decreased by a factor of three. At the beginning of 2011 the plasma density in the heliosheath began to increase and in mid-2012 it was up by more than a factor of two. The temperature rose by about 50% and the speed remained constant, although the flow direction continues to turn tailward. These changes may signal the end of solar minimum conditions at V2 in the heliosheath, although we do not understand why the speed did not decrease. The increased dynamic pressure has lead to an outward movement of the termination shock from its very compressed state at solar minimum.},
doi = {10.1088/2041-8205/759/1/L19},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}