While doing a transit study, you find an exoplanet around a nearby Sun-like star. The time between transits in P = 45 days. During a transit, the time from first to second contact is t₂ - t1 = 20 minutes and the time from first to third contact is t3 - t₁ = 5 hours. The depth of the transit is F = 0.05 (and we don't know the distance to the star so we can only measure the flux variation and not the luminosity variation; if we knew the distance this would then translate in ). 8.1 Draw a lightcurve of the transit labeling t₁, t2 and t3 and indicating the % in flux variation recorded. 8.2 What is the radius of the planet (in meters)? 8.3 What is the semi-major axis of the planet's orbit (in AU)? NOTE: to answer the last items you need to recall what we have seen in Module 2 about orbits. You can assume the planet is orbiting in an elliptical orbit.

While doing a transit study, you find an exoplanet around a nearby Sun-like star. The time between transits in \( \mathrm{P}=45 \) days. During a transit, the time from first to second contact is \( t_{2}-t_{1}=20 \) minutes and the time from first to third contact is \( t_{3}-t_{1}=5 \) hours. The depth of the transit is \( \frac{\delta F}{F}=0.05 \) (and we don't know the distance to the star so we can only measure the flux variation and not the luminosity variation; if we knew the distance this would then translate in \( \frac{\delta L}{L} \) ).
8.1 Draw a lightcurve of the transit labeling \( t_{1}, t_{2} \) and \( t_{3} \) and indicating the \( \% \) in flux variation recorded.
8.2 What is the radius of the planet (in meters)?
8.3 What is the semi-major axis of the planet's orbit (in \( \mathrm{AU} \) )?