The Evolving Shapes of Giants

Radio Stars in the Era of New Observatories

In April 2024, MIT Haystack Observatory hosted an international conference titled "Radio Stars in the Era of New Observatories" that was attended by more than 60 professional astronomers and other researchers from around the world. The meeting focused on how radio wavelength observations are being used to provide unique insights into the physics and evolution of the stars. Additionally, it showcased the latest advances in radio telescopes and other technologies that are enabling (or will soon enable) some of the most exciting discoveries in stellar astrophysics. In this episode, Radio Stars Producer Alex Griswold interviews several conference attendees to capture some of the scientific highlights from the meeting, as well as personal perspectives from those who participated.

What's Up with Betelgeuse? (Part 1)

Betelgeuse is a red supergiant star visible to sky watchers in the "shoulder" of the constellation of Orion, the Hunter. In late 2019 Betelgeuse began to undergo a surprising "dimming" event before recovering its typical brightness several months later. In this two-part podcast, hear how astronomers have been using observations at radio wavelengths, combined with data from other telescopes, to uncover the cause of this historic dimming event, and what it means for the future evolution of this star.

What's Up with Betelgeuse? (Part 2)

Betelgeuse is a red supergiant star visible to sky watchers in the "shoulder" of the constellation of Orion, the Hunter. In late 2019 Betelgeuse began to undergo a surprising "dimming" event before recovering its typical brightness several months later. In this two-part podcast, hear how astronomers have been using observations at radio wavelengths, combined with data from other telescopes, to uncover the cause of this historic dimming event, and what it means for the future evolution of this star.

Astronomy's First Radio Stars

Today we know that virtually all stars within our Galaxy emit radio waves. Using modern radio telescopes, astronomers routinely study these stellar radio waves to better understand how stars form, how they evolve, and how they die. However, for early radio astronomers, it was an enormous challenge to detect even the nearest radio star---the Sun. In this episode, we hear from astronomer and historian Dr. Ken Kellermann of the National Radio Astronomy Observatory about some of the pioneers of early radio astronomy, including Karl Jansky and Grote Reber, the challenges they faced, and how their work paved the way for current-day astronomers to use radio waves as a vital tool for understanding the astrophysics of Sun and other stars.

The Evolving Shapes of Giants

Even with the most powerful optical telescopes, the closest stars beyond the Sun generally appear as mere pinpoints of light, leaving us to only imagine what their light-emitting surfaces or "photospheres" might look like. However, using a technique known as radio interferometry, astronomers are now able to glimpse the faces of certain types of stars known as asymptotic giant branch stars (or "AGB stars" for short). What's more, the appearances of these AGB stars are seen to change over time. In this podcast, hear how astronomers are using radio interferometry to gain fascinating insights into what the future has in store for stars like the Sun as they reach old age.