Answer:
Compare spectra obtained before and during an eclipse
Step-by-step explanation:
- The passage of a planet between the star and the earth id called as a transit.
- The compassion between the spectral variation obtained from the light emitted by the planet can be used to find the presence of the exoplanet.
- The transiting planet has an atmosphere as some of the light passes from the sun and reaches the earth from the atmosphere of the planet.
- The brightness goes on decreasing as the planet passes out in an eclipse phase.