Distant Stars That Go Snap, Crackle, and Pop!

Mandelbaum residents had the honor of welcoming Kovi Rose for our first formal dinner of the semester. Kovi is an astrophysics PhD candidate at the University of Sydney, and he completed his undergraduate studies at the Hebrew University of Jerusalem.

The evening started with an Acknowledgement of Country, followed by a presentation on the wonders of radio astronomy. We learned about how these telescopes can operate in almost any weather condition and how radio arrays enhance resolution to detect celestial objects with incredible precision.

Kovi discussed the Australian Square Kilometre Array Pathfinder (ASKAP), a telescope with 36 antennas providing an expansive 30-square-degree field of view. He explained how the Rapid ASKAP Continuum Survey (RACS) has mapped 88% of the sky, making crucial data publicly available. Kovi also shared fascinating insights into transient radio signals and the discovery of unexpected sources in space.

Kovi took us on a journey through his research on transient objects, such as Active Galactic Nuclei (AGN), pulsars, and even mysterious unidentified sources. He shared the story of WISE J062309.94-045624.6, a T8 brown dwarf with an astonishing 66% circular polarization, challenging our understanding of stellar magnetic fields.

Kovi introduced us to the world of ultracool dwarfs—stars with temperatures below 3000 K. He explained how their radio bursts could provide insights into exoplanet habitability and how their strong magnetic fields drive these emissions. This led to a deeper discussion on auroral mechanisms, such as the Electron Cyclotron Maser Instability, which generates polarized radio waves.
One of the most engaging parts of the evening was Kovi’s discussion of follow-up observations using the Australia Telescope Compact Array (ATCA) and MeerKAT. We explored the periodicity of radio emissions, resembling auroras seen in Jupiter’s magnetic field, and speculated about potential star-planet interactions.

Kovi concluded his talk with an optimistic outlook on the future of radio astronomy. He highlighted upcoming surveys, including LOFAR and the Square Kilometre Array, which will further enhance our ability to detect and study faint radio sources.

I am extremely glad I had the opportunity to learn from Kovi, and I know that I, along with other residents, left the event with a newfound appreciation for radio astronomy and the hidden wonders of the universe.

Article by: Orelle Magnani (Mandelbaum House resident)

Photography: Andrew Montoni-Tiller and Yotam Kiper and (Mandelbaum House residents)