Exoplanet Transit Light Curve
A close orbiting gas giant sweeps across its star while the chart beneath tracks the fractional drop in brightness caused by the transit.
About this simulation
This scene recreates the most common way astronomers discover exoplanets: watching for the slight dimming of a star as a planet crosses in front of it. You can pause, resume, or simply let the transit repeat to see how the depth and duration of the brightness dip relate to the planet’s size and orbital speed.
The star uses a shader with rolling granulation to hint at convection cells, while the planet combines day and night textures plus a faint atmosphere rim. A chart underneath continuously plots stellar flux so you can correlate what the eye sees with the data that telescopes collect.
What to look for
The light curve dips most sharply when the planet is fully in front of the star. Notice how ingress and egress round off the curve edges, mirroring the gradual covering and uncovering of the stellar disk. Between transits the curve returns to unity, representing the baseline brightness.
- Transit depth reveals the ratio of planet radius to star radius.
- Transit duration hints at orbital speed and path length across the stellar face.
- Phase readout keeps time within the orbit so you can predict the next transit event.
Tech notes
The animation is powered by Three.js with an adaptive render loop that respects pause state, intersection observers, and reduced-motion preferences. A seeded history buffer drives the chart in Canvas 2D, rebuilding gradients only when the container is resized for consistent performance across devices.