StarTalk Radio: Cosmic Queries – Starquakes with Conny Aerts
Date: May 8, 2026
Host: Neil deGrasse Tyson
Co-host: Matt Kirshen
Guest: Prof. Conny Aerts (Astroseismology, KU Leuven & Radboud University)
Episode Overview
This engaging episode of StarTalk’s "Cosmic Queries" dives into the fascinating field of astroseismology—specifically, “starquakes.” Host Neil deGrasse Tyson and comic co-host Matt Kirshen are joined by Professor Conny Aerts, one of the world’s leading experts on the vibrations and “quakes” that ripple within stars across the universe. Through audience questions, the trio explores what starquakes are, why they matter, how they're detected, and what they reveal about the lives and inner secrets of stars. The conversation also covers the differences and similarities between planetary and stellar quakes, the technology used in their detection, real-life stellar mysteries (like Betelgeuse’s “Great Dimming”), and how the subtle music of the spheres can unlock cosmic evolution. The mood is lively, witty, and deeply curious, making complex astrophysics accessible—and fun.
Key Discussion Points & Insights
What is Astroseismology? (04:12 – 06:48)
- Conny Aerts explains: Astroseismology is “the study of the seismology of stars.”
- Unlike solid planets (with quakes arising from rigid crust shifts), stars are gaseous spheres and always moving. Starquakes are ongoing pressure and sound waves within stars, akin to vibrations in a concert hall.
- Quote: “Stars are three-dimensional musical halls—concert halls.” — Conny Aerts [06:48]
- These quakes let astronomers ‘see’ inside stars, much like geologists use earthquakes to probe Earth’s interior.
How Are Starquakes Detected? (06:48 – 09:17)
- Quakes in stars change their surface temperature and brightness in detectable patterns.
- Scientists observe tiny, periodic brightness variations—starquakes show up as subtle changes in light curves.
- “Each star has its own symphony…we [can] shift that global symphony into the audible range of humans. That’s called sonification.” — Conny Aerts [11:01]
- This enables, for instance, blind people to “hear the stars.”
The Music of the Spheres (09:17 – 11:07)
- Starquakes can be converted into sounds by shifting their natural frequencies into the audible range.
- Neil: “We have finally achieved the goals of the ancients by celebrating the music of the spheres.” [11:01]
- Conny: “Exactly. That’s true.” [11:07]
- This sonification is also important for accessibility and inclusion in astronomy.
Planetary vs. Stellar Quakes (12:13 – 15:51)
- Every object in nature “quakes”—planets (solid or gaseous), moons, even ice giants.
- The frequency and nature of these quakes depend on properties, especially density.
- For stars, brightness measurements from space-based telescopes (like Kepler/TESS) are used to study quakes, since we can’t physically place seismographs “there.”
What Can We Learn from Starquakes? (25:41 – 32:18)
- Unique insight: Starquakes reveal internal properties, especially stellar core rotation.
- “Thanks to the frequency shifts of these waves, we can now measure how stars rotate around. And what we have come to realize is that the theory of how stars evolve … is quite off.” — Conny Aerts [26:26]
- Internal rotation affects stellar mixing, longevity, and evolution in ways previously underestimated.
- “Stars have many more surprises than us astrophysicists have imagination.” — Conny Aerts [27:57]
- With about 2,000 stars measured, results show massive stars live somewhat longer than previously thought due to extra internal mixing.
Starquakes, Fusion, and Energy (32:30 – 34:55)
- Quakes can be caused by nuclear fusion turbulence, tidal effects from companions, or internal processes like convection.
- Starquakes themselves do not directly cause a star to explode or “lose mass” catastrophically, but they can impact mixing and evolution.
The Betelgeuse Dimming Mystery (36:24 – 40:40)
- The red supergiant star Betelgeuse dimmed dramatically in 2019/2020, spurring global curiosity.
- Conny explains: The dimming resulted from expelled stellar material temporarily blocking its light—common late in life for supergiant stars.
- “Astrophysicists have to be very patient, because the timescales for stars to do this stuff … are like hundreds of thousands of years.” — Conny Aerts [40:33]
- Despite speculation, Betelgeuse isn’t expected to go supernova imminently.
Observing Starquakes: Tools & Timescales (44:00 – 49:56)
- Space telescopes like Kepler and TESS are ideal for astroseismology due to their uninterrupted, long-duration observations.
- Resolution depends on length of observation: longer baseline = better frequency precision.
- Upcoming ESA’s PLATO mission will combine long-term and wide-sky coverage, with 24 telescopes in one instrument platform.
- “Astroseismologists are very patient people.” — Conny Aerts [47:08]
Starquakes and Solar Activity: Hazards to Earth? (50:02 – 53:09)
- Coronal mass ejections (CMEs) and sunspots can disrupt stellar oscillations, but not in a way dangerous to Earth.
- The Earth’s magnetic field largely protects us from high-energy particles; periodic solar oscillations (starquakes) are largely unaffected by transient flare events.
The Big Picture: Are All Stars Variable? (54:04 – 55:38)
- Every star oscillates—some more than others.
- Even “non-variable” stars, with sensitive enough instruments, can be shown to have subtle, continuous quakes.
- “[We're] measuring the action up to parts per million.” — Conny Aerts [55:36]
Notable Quotes & Memorable Moments
“Stars are three-dimensional concert halls. And the nice thing is, starquakes are always there.”
— Conny Aerts [06:48]
“We finally achieved the goals of the ancients by celebrating the music of the spheres.”
— Neil deGrasse Tyson [11:01]
“Stars have many more surprises than us astrophysicists have imagination.”
— Conny Aerts [27:57]
“Thanks to the frequency shifts of these waves, we can now measure how stars rotate around. And … the theory … is quite off.”
— Conny Aerts [26:26]
“If you were in the center of a star, you’d be dense too.”
— Neil deGrasse Tyson jokes to Matt [32:18]
“I nearly freaked out ... my whole life Betelgeuse was a certain brightness ... I cannot communicate my loss of breath.”
— Neil deGrasse Tyson on Betelgeuse [36:24]
“Astroseismologists are very patient people.”
— Conny Aerts [47:08]
Timestamps for Key Segments
- 04:12 – 06:48: What is astroseismology?
- 06:48 – 09:17: How are starquakes detected?
- 09:17 – 11:07: The music of the spheres; sonification for outreach/inclusion
- 12:27 – 15:51: Quakes on planets, moons, and differences between materials
- 25:41 – 32:18: What can starquakes reveal? Rotation, mixing, “stellar surprises”
- 36:24 – 40:40: The Betelgeuse dimming mystery
- 44:00 – 49:56: The role of Kepler, TESS, and PLATO in studying stellar oscillations
- 50:02 – 53:09: Starquakes, solar activity, and potential threats to Earth
- 54:04 – 55:38: All stars are variable; degrees of measurability
Episode Tone & Final Thoughts
The episode is playful, accessible, and packed with deep astrophysics—balancing humor (“How do you hide from a starquake?”), curiosity, and technical rigor. Conny Aerts brings clarity and passion to the cutting-edge study of starquakes, illuminating how stellar “music” has fundamentally revised our understanding of star life cycles, core physics, and cosmic history. For those new to astrophysics, it’s a rich crash-course in how starlight—and the faintest cosmic tremors—can resonate with human curiosity across light-years.
Summary prepared for listeners who want the insights and spirit of the episode—without the ads or filler.
