Detection and Characterization of a Coronal Mass Ejection Using Interplanetary Scintillation Measurements From the Murchison Widefield Array

• Published in: Space Weather 2023-05, Vol.21 (5), p.n/a
• Main Authors: Morgan, J., McCauley, P. I., Waszewski, A., Ekers, R., Chhetri, R.
• Format: Article
• Language: English
• Subjects: Arrays; Coronal mass ejection; Earth; Elongation; Geomagnetic storms; Heliosphere; Interplanetary scintillation; Interplanetary space; Kinematics; Magnetic storms; Radio telescopes; Scintillation; Solar surface; Storms; Tracking
• ISSN: 1542-7390; 1539-4964; 1542-7390
• DOI: 10.1029/2022SW003396

We have shown previously that the Murchison Widefield Array (MWA), can detect 100s of Interplanetary Scintillation (IPS) sources simultaneously across a field of view (FoV) ∼30° in extent. To test if we can use this capability to track heliospheric structures, we undertook a search of 88 hr of MWA IPS data, and identified an observation likely to have a significant Coronal Mass Ejection (CME) in the FoV. We demonstrate that in a single 5‐min MWA observation we are able to localize and image a CME ∼33 hr after launch at an elongation of ∼37° from the Sun. We use IPS observables to constrain the kinematics of the CME, and describe how MWA IPS observations can be used in the future to make a unique contribution to heliospheric modeling efforts. Plain Language Summary Coronal Mass Ejections (CMEs) are the link between events on the surface of the Sun, and Geomagnetic Storms on Earth. Tracking them through space is therefore critical to forecasting these important events. However, while there are many ways of detecting the launch of a CME and watching it leave the Sun, and ways we can detect them in orbit shortly before they arrive at the Earth, tracking them on their way through interplanetary space is much more tricky. In this paper we report on a detection of a CME in interplanetary space using a technique called Interplanetary Scintillation. This technique is certainly not new, however, we use a Radio telescope in Australia called the Murchison Widefield Array (MWA) which allows us to map the detected CME in unprecedented detail. We show how we can use MWA observations to track the CME as it heads on a trajectory away from the Earth. We hope that in the future we can use the same instrument and technique to track an Earthbound CME. Key Points We are able to recover a Coronal Mass Ejection (CME) detected in coronagraph images in Interplanetary Scintillation (IPS) observations taken 33 hr later The unprecedented number of lines of sight in our IPS observations allow us to image the CME and localize it to degree‐level accuracy The CME's location in the IPS observation is consistent with fast CME‐propagation, and confirms a “broad‐side” (plane of sky) trajectory