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.
