A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022
Voyager 1 has been moving through the very local interstellar medium (VLISM) for approximately one solar cycle, from 122.58 au on 2012/DOY 238 (August 25) to 158.5 au on 2023.0. Previously, an abrupt increase (“jump”) in the magnetic field strength B and proton density N by a factor of 1.35 and 1.36...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acd6eb |
| _version_ | 1797694059094999040 |
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| author | L. F. Burlaga N. Pogorelov L. K. Jian J. Park A. Szabo N. F. Ness |
| author_facet | L. F. Burlaga N. Pogorelov L. K. Jian J. Park A. Szabo N. F. Ness |
| author_sort | L. F. Burlaga |
| collection | DOAJ |
| description | Voyager 1 has been moving through the very local interstellar medium (VLISM) for approximately one solar cycle, from 122.58 au on 2012/DOY 238 (August 25) to 158.5 au on 2023.0. Previously, an abrupt increase (“jump”) in the magnetic field strength B and proton density N by a factor of 1.35 and 1.36, respectively, was observed during an interval of ∼8 days in 2020.40. After the jump, B continued to increase to a maximum value ∼0.56 nT at ∼2021.4 and then declined until B returned to the postjump value of 0.5 nT on 2021.85, 1.45 yr after the jump. The magnetic field strength declined briefly from 0.5 nT on 2021.85 to 0.47 nT on 2021.95 and then increased sporadically to 0.52 nT at 2023.0. Thus, the magnetic field strength remained strong for at least 2.6 yr. The magnetic hump and the density hump were a compression wave propagating through the VLISM. The compression wave was generated by a region with large dynamic pressure in the solar wind that propagated through the inner heliosheath and collided with the heliopause. The magnetic field strength continued to remain strong, with slow variations, until the end of our observations at 2023.0. It is suggested that the magnetic hump evolved from the large dynamic pressure, high speeds, and density observed at 1 au between ∼2015 and ∼2017. |
| first_indexed | 2024-03-12T02:52:30Z |
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| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T02:52:30Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-b44d68d456014c9c97907e640d455cb12023-09-03T15:30:02ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01953213510.3847/1538-4357/acd6ebA Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022L. F. Burlaga0https://orcid.org/0000-0002-5569-1553N. Pogorelov1https://orcid.org/0000-0002-6409-2392L. K. Jian2https://orcid.org/0000-0002-6849-5527J. Park3https://orcid.org/0000-0002-8989-4631A. Szabo4https://orcid.org/0000-0003-3255-9071N. F. Ness5Leonard F. Burlaga, Inc. , Davidsonville, MD 21035, USA ; lburlagahsp@verizon.netUniversity of Alabama in Huntsville , Huntsville, AL 35899, USAHeliophysics Science Division , NASA/GSFC, Greenbelt, MD 20771, USAUniversity of Maryland , Baltimore County, Baltimore, MD 21250, USAHeliophysics Science Division , NASA/GSFC, Greenbelt, MD 20771, USAIndependent scholar , Landenberg, PA 19350-9350, USAVoyager 1 has been moving through the very local interstellar medium (VLISM) for approximately one solar cycle, from 122.58 au on 2012/DOY 238 (August 25) to 158.5 au on 2023.0. Previously, an abrupt increase (“jump”) in the magnetic field strength B and proton density N by a factor of 1.35 and 1.36, respectively, was observed during an interval of ∼8 days in 2020.40. After the jump, B continued to increase to a maximum value ∼0.56 nT at ∼2021.4 and then declined until B returned to the postjump value of 0.5 nT on 2021.85, 1.45 yr after the jump. The magnetic field strength declined briefly from 0.5 nT on 2021.85 to 0.47 nT on 2021.95 and then increased sporadically to 0.52 nT at 2023.0. Thus, the magnetic field strength remained strong for at least 2.6 yr. The magnetic hump and the density hump were a compression wave propagating through the VLISM. The compression wave was generated by a region with large dynamic pressure in the solar wind that propagated through the inner heliosheath and collided with the heliopause. The magnetic field strength continued to remain strong, with slow variations, until the end of our observations at 2023.0. It is suggested that the magnetic hump evolved from the large dynamic pressure, high speeds, and density observed at 1 au between ∼2015 and ∼2017.https://doi.org/10.3847/1538-4357/acd6ebInterstellar magnetic fields |
| spellingShingle | L. F. Burlaga N. Pogorelov L. K. Jian J. Park A. Szabo N. F. Ness A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 The Astrophysical Journal Interstellar magnetic fields |
| title | A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 |
| title_full | A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 |
| title_fullStr | A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 |
| title_full_unstemmed | A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 |
| title_short | A Large Magnetic Hump in the VLISM Observed by Voyager 1 in 2020–2022 |
| title_sort | large magnetic hump in the vlism observed by voyager 1 in 2020 2022 |
| topic | Interstellar magnetic fields |
| url | https://doi.org/10.3847/1538-4357/acd6eb |
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