Browsing by Author "Fedorets, Grigori"

The investigation of rotation of asteroids is an important means to deriving information about their physical properties and processes using ground-based instrumentation. The rotation rate distribution imply the significance of non-gravitational forces depending on the size of the asteroid. The absence of certain rotation rates in the asteroid population poses constraints on the inner structure of asteroids of different sizes. The majority of rotation periods of asteroids solved from photometric lightcurves belong to fast rotators. The observation time required for obtaining an accurate period estimate is substantially longer for a slowly rotating asteroid than for a rapidly rotating asteroid. Therefore, lightcurve surveys with limited observation time which allocate the same amount of time for all asteroids, are expected to only produce accurate periods for asteroids with short rotation periods. This thesis concentrates on various aspects of asteroid rotation. Methods used to obtain asteroid rotation periods and shape models are discussed. Also, physical mechanisms affecting the rotation of asteroids are considered. The focus is on the main-belt objects and slowly rotating bodies. The Thousand Asteroid Lightcurve Survey (Masiero et al. 2009) carried out with the Canada-France-Hawaii Telescope was one of the first systematic asteroid lightcurve surveys. One of the objects selected for follow-up was Hungaria asteroid (39420) 2084 T-2. Masiero et al. (2009) quoted a rotation period of 105 ± 21 h which is a relatively inaccurate solution, especially compared to the solutions for the fast rotators. In this work we present an updated period fit as well as a possible convex shape solution (Kaasalainen \& Torppa 2001, Kaasalainen et al. 2001) for the asteroid. The possibility that the investigated asteroid is a close binary or a non-principal-axis rotator is also discussed.