Toggle between the rippling surface view and the interior cutaway, then drag the amplitude slider to see why the Sun's five-minute pulse is invisible to the eye but unmistakable to a helioseismic instrument.
The Sun's whole visible surface rises and falls in a five-minute rhythm, produced by sound waves (called p-modes) trapped inside the Sun. Instruments on SOHO, GONG, and SDO/HMI track millions of these modes at once; inverting that data tells astronomers where the Sun's outer convecting layer meets its calmer interior - a boundary pinned down at 0.713 solar radii - without ever sending a probe inside.
Drag to orbit and scroll or pinch to zoom. For the Sun's overall layered structure, see the Sun Structure 3D Explorer; for the surface convection cells this technique probes from below, see the Solar Granulation 3D Explorer.
Helioseismology Sun Oscillation 3D Explorer
This browser explorer visualizes the Sun's five-minute surface oscillation - the sound-wave pattern astronomers read like a sonogram to measure the boundary between the Sun's convecting outer layer and its calmer interior, a boundary independently measured at 0.713 solar radii.
The oscillation is real and constant: the Sun's whole visible disk rises and falls by a few hundred meters per second in a rhythm centered near five minutes (about 3 millihertz), produced by sound waves (p-modes) trapped inside the Sun. Instruments on SOHO, GONG, and SDO/HMI track millions of these resonant modes simultaneously. Helioseismic inversion of that data places the base of the Sun's convection zone at 0.713 +/- 0.001 solar radii, and locates the tachocline - the thin shear layer where the differentially-rotating convection zone meets the uniformly-rotating radiative interior - at roughly 0.69-0.72 solar radii depending on the inversion method and latitude, with a thickness of about 0.006-0.05 solar radii. The tachocline is the leading candidate site for the process that generates the Sun's 11-year magnetic cycle.
- Toggle "Show interior cutaway" to switch between the rippling surface view and a cross-section showing the measured 0.713-solar-radii boundary
- Drag the wave amplitude slider to make the ripple pattern easier or harder to see
- Click "Next wave pattern" to cycle through simplified example oscillation patterns
- Drag to orbit, scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
| Figure | Value |
|---|---|
| Characteristic oscillation period | about 5 minutes (about 3 millihertz), the "five-minute oscillation" |
| Resonant modes tracked | millions, observed by SOHO, GONG, and SDO/HMI |
| Measured base of convection zone | 0.713 +/- 0.001 solar radii |
| Tachocline location | about 0.69-0.72 solar radii (method/latitude dependent); thickness about 0.006-0.05 solar radii |
| Why it matters | leading candidate site for the Sun's 11-year magnetic dynamo |
For the Sun's overall layered structure, open the Sun Structure 3D Explorer; for a close-up of the surface convection cells this technique probes from underneath, open the Solar Granulation 3D Explorer.
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached.
This is an educational approximation, not a physical simulation. The real five-minute oscillation is far too slow and far too subtle - surface motions of only a few hundred meters per second - to see directly at this speed and scale, so the ripple pattern, its speed, and its red/blue coloring (mimicking the Doppler maps real observatories publish) are exaggerated for visibility. The period, mode count, and boundary figures above are the real measured ones.
Frequently Asked Questions
What is the Sun's five-minute oscillation?
It is a real, constantly-present rhythm in which the Sun's whole visible surface rises and falls by a few hundred meters per second, centered near a five-minute period (about 3 millihertz). It is produced by sound waves, called p-modes, trapped inside the Sun.
How do astronomers use this oscillation to see inside the Sun?
Instruments on SOHO, GONG, and SDO/HMI track millions of resonant modes at once. Inverting that data - a technique called helioseismology - reveals the Sun's internal structure and rotation the way a sonogram reveals a body's interior, without ever sending a probe inside.
What is the tachocline?
The tachocline is the thin shear layer where the Sun's differentially-rotating outer convection zone meets its uniformly-rotating radiative interior, located at roughly 0.69-0.72 solar radii with a thickness of about 0.006-0.05 solar radii. It is the leading candidate site for the dynamo that generates the Sun's 11-year magnetic cycle.
How precisely is the convection-zone boundary known?
Helioseismic inversion independently measures the base of the convection zone at 0.713 +/- 0.001 solar radii - one of the most precisely known boundaries inside any star.
Is the ripple animation showing the real oscillation speed?
No. The real five-minute oscillation involves surface motions of only a few hundred meters per second and would be far too slow and subtle to notice at real speed and scale, so this page speeds up and exaggerates the ripple pattern for visibility. The period, mode count, and boundary figures in the facts panel are the real measured ones.
Why are the colors red and blue?
The coloring mimics the red/blue Doppler maps real solar observatories publish, marking whether a point on the simplified wave pattern is moving outward or inward - it is not a temperature map.
How is this different from the Sun Structure page?
The Sun Structure 3D Explorer shows a static cutaway diagram of the Sun's layers. This page is about the diagnostic method itself - how surface sound waves reveal the boundary between layers - and is not a duplicate of that static diagram.