The light curve shows the star's brightness over time. When the planet transits in front of the star, it blocks a small portion of the star's light, creating a characteristic dip in the light curve.
Transit Depth: 5.00%(Proportional to (Rplanet/Rstar)2)
The transit method detects exoplanets by measuring the periodic dimming of a star's light as a planet passes in front of it. This technique has been used by NASA's Kepler and TESS missions to discover thousands of exoplanets.
The amount of dimming (transit depth) tells us about the planet's size relative to its star. The time between transits reveals the planet's orbital period, while the transit duration provides information about the orbit's shape.
Transits can only be detected when the planet's orbit is aligned with our line of sight to the star, which means we miss many planetary systems.
The dimming effect is very small—typically less than 1% for a Jupiter-sized planet orbiting a Sun-like star, and only 0.01% for an Earth-sized planet.
Stars naturally vary in brightness due to starspots and flares, which can mask or mimic transit signals.