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.
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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.
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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.
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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.
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10:53
Stellar Shape-Shifters
Planetary nebulae form when a wind from a dying star blows away its outer layers, enveloping the star in a cloud of debris that can span many light years across. Often planetary nebulae have spectacularly complex shapes, leading to whimsical nicknames such as "Eskimo" or "Cat's Eye". However, the origin of these diverse shapes has been a long-standing puzzle; if the progenitor stars are spherical and lose mass uniformly in all directions, what sculpts their ejecta into these varied forms? Using observations of circumstellar radio waves, scientists are discovering that part of the answer is that the outflows from some dying stars are far more complex than once believed.
This podcast explores how two types of radio wavelength observations of dying stars are being combined to offer new insights into the origin of the intricately-shaped stellar ejecta known as planetary nebulae.
When we think of starlight, we typically think of the visible light stars emit against the backdrop of the night sky. But did you know that virtually all stars also emit radio waves?
"Radio Stars" is a podcast series that explores how observations at radio wavelengths reveal surprising new insights into the lives and deaths of stars in our Galaxy.
In this series, you will have a chance to discover more about how radio observations are revealing previously hidden secrets in the lives of some of the most familiar stars in the sky.
The Radio Stars podcasts have been funded by a series of grants from the National Science Foundation to Dr. Lynn D. Matthews, Principal Research Scientist at MIT Haystack Observatory.
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