Speaker
Description
Detection of auroral radio emission from exoplanets presents a unique opportunity to directly probe their magnetic fields. By studying the magnetic characteristics of exoplanets, we can better-understand their atmospheric retention, long-term evolution, and ultimately their habitability. However, an unambiguous detection remains elusive, largely due to limited sensitivity at low radio frequencies. Ultracool dwarfs (UCDs), with masses between those of low-mass stars and giant planets, provide an important bridge between stellar and planetary magnetism. As fully convective, rapidly rotating objects, they sustain strong, large-scale magnetic fields that power auroral radio emission. Such emission has been detected from UCDs for over two decades, establishing them as key analogues of Jupiter-like planets and offering a valuable comparison to exoplanets, where detections have yet to be confirmed.
To date, auroral radio emission from UCDs has been observed at both high and low radio frequencies, corresponding to strong and weak magnetic field strengths, respectively. However, UCD aurorae have yet to be detected in the 400-800 MHz range, leaving open the question of whether objects at the star–planet boundary possess intermediate-strength magnetic fields. In this talk, I will present the first survey of 115 UCDs in this frequency range using the CHIME radio telescope. I will demonstrate how monitoring the rotational variability of auroral emission from each of our targets will enable us to characterise their magnetic fields. Finally, I will show how this developed framework will facilitate long term monitoring of magnetic activity of objects at the star-planet boundary, providing new constraints on how magnetism manifests from stars to planets.
| Talk category | NOVA Network 2 |
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