Name of the Speaker(s):Holger Bock
Institution: Landessternwarte Heidelberg
Title of the communication: Spectral index variations of Blazars
Preliminary abstract (12 lines max.):
From our previous research we know the IDV
phenomenon to be typical of the Blazar
class. In order to study the radiation
processes in the optical thin part of the
spectrum, we investigated a sample of
northern, highly variable blazars for
variations of the spectral indices with
time scales of about 1 hour.
Our results from UBVRI-observations of
3C66A, 0716+71, OJ 287, 0954+65 and
Mkn 421 will be presented.
