Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array

Abstract We have conducted a blind search in 49 consecutive days of interplanetary scintillation observations made by the Murchison Widefield Array from mid‐2019, with overlapping daily observations approximately East and South‐East of the Sun at an elongation of ∼30° and a field of view of 30°. The...

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Main Authors: A. Waszewski, J. S. Morgan, R. Chhetri, R. Ekers, M. C. M. Cheung, N. D. R. Bhat, M. Johnston‐Hollitt
Format: Article
Language:English
Published: Wiley 2023-10-01
Series:Space Weather
Online Access:https://doi.org/10.1029/2023SW003570
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author A. Waszewski
J. S. Morgan
R. Chhetri
R. Ekers
M. C. M. Cheung
N. D. R. Bhat
M. Johnston‐Hollitt
author_facet A. Waszewski
J. S. Morgan
R. Chhetri
R. Ekers
M. C. M. Cheung
N. D. R. Bhat
M. Johnston‐Hollitt
author_sort A. Waszewski
collection DOAJ
description Abstract We have conducted a blind search in 49 consecutive days of interplanetary scintillation observations made by the Murchison Widefield Array from mid‐2019, with overlapping daily observations approximately East and South‐East of the Sun at an elongation of ∼30° and a field of view of 30°. These observations detect an unprecedented density of sources. In spite of these observations being taken at sunspot minimum, this search has revealed several interesting transitory features characterized by elevated scintillation levels. One solar wind enhancement is captured in two observations several hours apart, allowing its radial movement away from the Sun to be measured. We present here a methodology for measuring the plane‐of‐sky velocity for the moving heliospheric structure. The plane‐of‐sky velocity was inferred as 0.66 ± 0.147 hr−1, or 480 ± 106 kms−1 assuming a distance of 1AU. After cross‐referencing our observed structure with multiple catalogs of heliospheric events, we propose that the likely source of our observed structure is a stream‐interaction region originating from a low‐latitude coronal hole. This work demonstrates the power of widefield interplanetary scintillation observations to capture detailed features in the heliosphere which are otherwise unresolvable and go undetected.
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institution Kabale University
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spelling doaj-art-e662766acb58498e9e12ef44cd152dea2025-01-14T16:31:16ZengWileySpace Weather1542-73902023-10-012110n/an/a10.1029/2023SW003570Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield ArrayA. Waszewski0J. S. Morgan1R. Chhetri2R. Ekers3M. C. M. Cheung4N. D. R. Bhat5M. Johnston‐Hollitt6International Centre for Radio Astronomy Research Curtin University Bentley AustraliaInternational Centre for Radio Astronomy Research Curtin University Bentley AustraliaCSIRO Space and Astronomy Bentley WA AustraliaInternational Centre for Radio Astronomy Research Curtin University Bentley AustraliaCSIRO Space and Astronomy Epping NSW AustraliaInternational Centre for Radio Astronomy Research Curtin University Bentley AustraliaCurtin Institute for Data Science Curtin University Bentley WA AustraliaAbstract We have conducted a blind search in 49 consecutive days of interplanetary scintillation observations made by the Murchison Widefield Array from mid‐2019, with overlapping daily observations approximately East and South‐East of the Sun at an elongation of ∼30° and a field of view of 30°. These observations detect an unprecedented density of sources. In spite of these observations being taken at sunspot minimum, this search has revealed several interesting transitory features characterized by elevated scintillation levels. One solar wind enhancement is captured in two observations several hours apart, allowing its radial movement away from the Sun to be measured. We present here a methodology for measuring the plane‐of‐sky velocity for the moving heliospheric structure. The plane‐of‐sky velocity was inferred as 0.66 ± 0.147 hr−1, or 480 ± 106 kms−1 assuming a distance of 1AU. After cross‐referencing our observed structure with multiple catalogs of heliospheric events, we propose that the likely source of our observed structure is a stream‐interaction region originating from a low‐latitude coronal hole. This work demonstrates the power of widefield interplanetary scintillation observations to capture detailed features in the heliosphere which are otherwise unresolvable and go undetected.https://doi.org/10.1029/2023SW003570
spellingShingle A. Waszewski
J. S. Morgan
R. Chhetri
R. Ekers
M. C. M. Cheung
N. D. R. Bhat
M. Johnston‐Hollitt
Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
Space Weather
title Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
title_full Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
title_fullStr Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
title_full_unstemmed Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
title_short Resolving Moving Heliospheric Structures Using Interplanetary Scintillation Observations With the Murchison Widefield Array
title_sort resolving moving heliospheric structures using interplanetary scintillation observations with the murchison widefield array
url https://doi.org/10.1029/2023SW003570
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