A Flare-Type IV Burst Event from Proxima Centauri and Implications for Space Weather

TL;DR

This study reports the first detection of a solar-like type IV radio burst from Proxima Centauri, linking stellar radio bursts to space weather phenomena and implications for exoplanet habitability.

Contribution

It provides the first interferometric observation of a coherent stellar radio burst coincident with a flare, identifying it as a type IV burst and suggesting a new method to trace stellar coronal mass ejections.

Findings

Detected a long-duration optical flare with associated radio bursts from Proxima Centauri.

Identified the radio burst as a type IV, similar to solar bursts.

Implications for using type IV bursts as indicators of stellar coronal mass ejections.

Abstract

Studies of solar radio bursts play an important role in understanding the dynamics and acceleration processes behind solar space weather events, and the influence of solar magnetic activity on solar system planets. Similar low-frequency bursts detected from active M-dwarfs are expected to probe their space weather environments and therefore the habitability of their planetary companions. Active M-dwarfs produce frequent, powerful flares which, along with radio emission, reveal conditions within their atmospheres. However, to date, only one candidate solar-like coherent radio burst has been identified from these stars, preventing robust observational constraints on their space weather environment. During simultaneous optical and radio monitoring of the nearby dM5.5e star Proxima Centauri, we detected a bright, long-duration optical flare, accompanied by a series of intense, coherent radio bursts. These detections include the first example of an interferometrically detected coherent stellar radio burst temporally coincident with a flare, strongly indicating a causal relationship between these transient events. The polarization and temporal structure of the trailing long-duration burst enable us to identify it as a type IV burst. This represents the most compelling detection of a solar-like radio burst from another star to date. Solar type IV bursts are strongly associated with space weather events such as coronal mass ejections and solar energetic particle events, suggesting that stellar type IV bursts may be used as a tracer of stellar coronal mass ejections. We discuss the implications of this event for the occurrence of coronal mass ejections from Proxima Cen and other active M-dwarfs.