Exploiting the transit timing capabilities of Ariel

Abstract The Transit Timing Variation (TTV) technique is a powerful dynamical tool to measure exoplanetary masses by analysing transit light curves. We assessed the timing performances of Ariel Fine Guidance Sensors (FGS1/2) based on simulated curve bright, 55 Cnc, and faint, K2-24, planet-hosting star. estimated through Markov-Chain Monte-Carlo analysis time uncertainty at nominal cadence 1 second and, as comparison, 30 60-s cadence. found that will be able with precision about 12s 34s, for star bright Cnc respectively. then ran simulations, also including errors, we an improvement measurement planetary 20-30% in K2-24-like system TTVs. conditions allow us detect TTV signal induced hypothetical external perturber within mass range between Earth Neptune using 10 curves .