Ph.D. thesis:   "Study of rotation periods of single and binary asteroids using photometric observations"

adviser: Prof. T.Michalowski

The main goal of this work is to study the rotation periods of single and binary asteroids by means of photometric observations. Analysis of the rotation periods of small bodies from different groups brings valuable knowledge about the nature of these bodies. Since it was discovered that asteroids belonging to Koronis family show non-random orientations of their rotation axes and spin rates, studing asteroid rotations became an important way to understand their evolution and nature. Non-random distribution of asteroid spins can be explained by the long - term dynamical evolution, called the Yarkovsky effect.
  Present work relates to three different groups of small bodies of the Solar System and the scientific projects connected to them carried out at the Astronomical Observatory of Adam Mickiewicz University of Poznan: studying the physical properties of the Flora Family asteroids, a survey of very small Near Earth Asteroids, and a study of synchronous binary objects.
  The first three chapters of this work describe the theory of Solar System formation, asteroids and their groups. They also present the current state of knowledge about the rotation periods of asteroids and some processes which can affect them. These chapters also include the description of various observational techniques of asteroids, with the stress on photometric observations, used in this work.
  Chapter number four concentrates on Flora family asteroids. It contains the current state of knowledge about this family, example results of photometric observations of five asteroids and a summary of the physical properties with the rotation periods for 115 objects which belong to this family.
  The main topic of the fifth chapter are Near Earth Asteroids and the observing campaign with SALT telescope targeted at them. For three objects there are photometric observations presented plus the rotation periods derived from them. The observed asteroids are classified as very small objects with fast rotation, a group of asteroids still not well known.
  The last chapter contains the characteristics of binary asteroids and their physical properties. There are four synchronous binary systems presented. For two of them: 809 Lundia, and 4492 Debussy, in addition to photometric observations we present also their models. The models consist of two ellipsoidal shape models, rotation periods, ecliptic coordinates of their orbital poles, the separation between two components and their mass ratio. Observing and modeling the binary objects is one of a few possible ways to get information about the crucial parameter of small bodies densities.