Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium
Voyager 1 and 2 data from the vicinity of the heliopause and very local interstellar medium are reexamined to better understand the confounding lack of rotation in the magnetic field ( B -field) across the heliopause observed by both Voyagers, despite their very large spatial separations (>100 au...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad05d3 |
| _version_ | 1797360431291957248 |
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| author | Drew L. Turner Adam Michael Elena Provornikova Marc Kornbleuth Merav Opher Stefan Eriksson Benoit Lavraud Parisa Mostafavi Matthew E. Hill Pontus Brandt Ian J. Cohen Joseph Westlake John D. Richardson Nathan A. Schwadron David J. McComas |
| author_facet | Drew L. Turner Adam Michael Elena Provornikova Marc Kornbleuth Merav Opher Stefan Eriksson Benoit Lavraud Parisa Mostafavi Matthew E. Hill Pontus Brandt Ian J. Cohen Joseph Westlake John D. Richardson Nathan A. Schwadron David J. McComas |
| author_sort | Drew L. Turner |
| collection | DOAJ |
| description | Voyager 1 and 2 data from the vicinity of the heliopause and very local interstellar medium are reexamined to better understand the confounding lack of rotation in the magnetic field ( B -field) across the heliopause observed by both Voyagers, despite their very large spatial separations (>100 au). Using three estimates for the orientation of the B -field in the pristine interstellar medium and four models of the heliosphere, we calculate draped interstellar B -field orientations along the model heliopauses and compare those estimates to the Voyager observations. At both Voyagers, expected draped B -fields are inconsistent with the observed B -field orientations after the boundary crossings. Furthermore, we show how the longer-term trends of the observed B -fields at both Voyagers after the crossings actually rotated away from both the expected draped B -field and the pristine interstellar B -field directions. We develop evidence, including an illustrative and analogous set of observations from Magnetospheric Multiscale spacecraft along Earth’s magnetopause, in support of a hypothesis that both Voyagers transited a thick boundary layer of reconnected magnetic flux along the heliopause surface. We estimate that Voyager 1 has not yet fully transited this boundary layer, the radial thickness of which at the Voyager 1 crossing location may be >18 au and likely much thicker. Meanwhile, at Voyager 2's crossing location, the boundary layer is likely much thinner, and for Voyager 2, we present evidence that Voyager 2 might already have transited the boundary layer and entered a region of fields and plasma that were never connected to the Sun—the very local interstellar medium. |
| first_indexed | 2024-03-08T15:38:28Z |
| format | Article |
| id | doaj.art-229cd18c7b424fadacc6eb5fb5f5970b |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T15:38:28Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-229cd18c7b424fadacc6eb5fb5f5970b2024-01-09T15:52:22ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01960213010.3847/1538-4357/ad05d3Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar MediumDrew L. Turner0https://orcid.org/0000-0002-2425-7818Adam Michael1https://orcid.org/0000-0003-2227-1242Elena Provornikova2Marc Kornbleuth3https://orcid.org/0000-0002-3479-1766Merav Opher4https://orcid.org/0000-0002-8767-8273Stefan Eriksson5https://orcid.org/0000-0002-5619-1577Benoit Lavraud6https://orcid.org/0000-0001-6807-8494Parisa Mostafavi7https://orcid.org/0000-0002-3808-3580Matthew E. Hill8https://orcid.org/0000-0002-5674-4936Pontus Brandt9Ian J. Cohen10https://orcid.org/0000-0002-9163-6009Joseph Westlake11https://orcid.org/0000-0003-0472-8640John D. Richardson12https://orcid.org/0000-0003-4041-7540Nathan A. Schwadron13https://orcid.org/0000-0002-3737-9283David J. McComas14https://orcid.org/0000-0001-6160-1158Johns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USABoston University , Boston, MA 02215, USABoston University , Boston, MA 02215, USALaboratory for Atmospheric and Space Physics, University of Colorado , Boulder, CO 80309, USALaboratoire d’Astrophysique de Bordeaux, Université de Bordeaux , CNRS, Pessac, FranceJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Rd., Laurel, MD 20723, USAMassachusetts Institute of Technology , 37-655, Cambridge, MA 02139, USAUniversity of New Hampshire , Durham, NH 03824, USADept. of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USAVoyager 1 and 2 data from the vicinity of the heliopause and very local interstellar medium are reexamined to better understand the confounding lack of rotation in the magnetic field ( B -field) across the heliopause observed by both Voyagers, despite their very large spatial separations (>100 au). Using three estimates for the orientation of the B -field in the pristine interstellar medium and four models of the heliosphere, we calculate draped interstellar B -field orientations along the model heliopauses and compare those estimates to the Voyager observations. At both Voyagers, expected draped B -fields are inconsistent with the observed B -field orientations after the boundary crossings. Furthermore, we show how the longer-term trends of the observed B -fields at both Voyagers after the crossings actually rotated away from both the expected draped B -field and the pristine interstellar B -field directions. We develop evidence, including an illustrative and analogous set of observations from Magnetospheric Multiscale spacecraft along Earth’s magnetopause, in support of a hypothesis that both Voyagers transited a thick boundary layer of reconnected magnetic flux along the heliopause surface. We estimate that Voyager 1 has not yet fully transited this boundary layer, the radial thickness of which at the Voyager 1 crossing location may be >18 au and likely much thicker. Meanwhile, at Voyager 2's crossing location, the boundary layer is likely much thinner, and for Voyager 2, we present evidence that Voyager 2 might already have transited the boundary layer and entered a region of fields and plasma that were never connected to the Sun—the very local interstellar medium.https://doi.org/10.3847/1538-4357/ad05d3HeliopauseStellar-interstellar interactionsHeliosheathHeliosphereAstrospheresInterstellar medium |
| spellingShingle | Drew L. Turner Adam Michael Elena Provornikova Marc Kornbleuth Merav Opher Stefan Eriksson Benoit Lavraud Parisa Mostafavi Matthew E. Hill Pontus Brandt Ian J. Cohen Joseph Westlake John D. Richardson Nathan A. Schwadron David J. McComas Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium The Astrophysical Journal Heliopause Stellar-interstellar interactions Heliosheath Heliosphere Astrospheres Interstellar medium |
| title | Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium |
| title_full | Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium |
| title_fullStr | Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium |
| title_full_unstemmed | Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium |
| title_short | Evidence of a Thick Heliopause Boundary Layer Resulting from Active Magnetic Reconnection with the Interstellar Medium |
| title_sort | evidence of a thick heliopause boundary layer resulting from active magnetic reconnection with the interstellar medium |
| topic | Heliopause Stellar-interstellar interactions Heliosheath Heliosphere Astrospheres Interstellar medium |
| url | https://doi.org/10.3847/1538-4357/ad05d3 |
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