One of the next big steps forward for exoplanet science would be the detection of moons around extrasolar planets. In this thesis I investigate the exomoon candidate around the exoplanet Kepler-1625 b. I estimate the parameters of the exomoon by fitting the Kepler transit light curve. The presence of an exomoon is marginally statistically significant. Tests of the exomoon detection algorithm using synthetic light curves show that about 40% of the injected moons are correctly identified. However, there is a 10-20% false-positive exomoon recovery rate.
Combining Kepler observations with additional follow-up observations by the Hubble Space Telescope leads to higher statistical significance of the presence of the exomoon. There are still many open questions, such as the possibility of another planet in the system and the effect of non-white noise on the false-positive detection rate of moon candidates.
I also study other indicators that can help identify exomoon signatures. The variations of the transit timing and transit duration are not as good indicators as previously thought. However, the transit depth variations induced by the exomoon follow a periodic pattern that may be detectable.
Keywords: astrophysics; exoplanets; exomoons; data analysis; transit light curve; data analysis
