Perpustakaan Digital ITB

Rossiter-McLaughlin (RM) effect is a distortion of stellar radial velocity which is caused due to transit phenomenon of an exoplanet. Based on the light curve of a star during the transit phenomenon of planet companion, both radii of host star and planet can be determined. Degree of distortion depends on the value of the angle between projected stellar spin axis and planet orbital axis (?), and Stellar rotational velocity (????sin????). Moreover, by analyzing radial velocity variation in radial velocity curve of a star, we are able to measure the orbital parameters of star and planet especially the degree of misalignment between projected stellar spin axis and planet orbit axis, hence key information for the study of formation and evolution of exoplanetary system can be provided. This work conducts study and analysis of Rossiter-McLaughlin effect of stellar radial velocity curve for transiting exoplanets by employing a model developed by Gimenez (2005, 2006). Moreover, we applied this model to obtain the final value of orbital parameters as the result of best-fit model of RM effect for HAT-P-17b, TrES-4b and HAT-P-1b transit. We found that the angle between stellar spin axis and planet orbit of HAT-P-17 is misaligned with ? =19?, meanwhile TrES-4 with ? = 7.3? and HAT-P-1 with ? = 3.4? are assumed to have well-aligned orbit with their exoplanet companions. In addition, this work found that the rotational velocity of TrES-4 is ????sin????= 9.5 km s-1 instead of ????sin????= 8.3 km s-1 as reported by Narita et al. (2010), we also reported higher value of rotational velocity for HAT-P-17 which is ????sin????= 0.80 km s-1 than the value which was reported by Fulton et al. (2018) which is 0.56 km s-1. While, for the rotational velocity of HAT-P-1 found in this work is identic as Johnson et al. (2008) obtained which is ????sin????= 3.75 km s-1.