Speaker: Young-Jun Choi
Place: Holcblat
Time: Wednesday, 16/Jun/2004, 14:00
Title: Kuiper Belt Objects: observation and theory (PhD thesis)
Abstract
This project consists of an observational analysis of several Kuiper belt objects (KBOs) and a theoretical study of their thermal structure and evolution. I performed photometric observations with a 1-m telescope at Wise Observatory during three years, from September 2000 to October 2003, for six KBOs. The rotational periods and their radii and axis ratios were derived from the lightcurves. In addition, color variations and phase effects were investigated. In parallel, I calculated the long-term thermal evolution of several models with characteristics typical of KBOs. The energy sources of young KBOs taken to be the external heat source from the early Sun and the internal heat source from radioactive species (in particular 26Al) are comparable at the typical distance of KBOs from the Sun (~ 40 AU). The models suggest that KBOs are likely to lose the ices of very volatile species during early evolution and the internal structure of KBOs is most probably not uniform but stratified with the outer layers being less altered by evolution. Additionally, I found that cometary activity was not rare for the orbits of Centaurs and some of scattered KBOs even without radiogenic heating.