Photometry of Centaurs 1997 CU<SUB>26</SUB> and 1999 UG<SUB>5</SUB>

We present some preliminary results on BVRI photometry performed on two Centaurs at the 1.52 meter National Astronomical Observatory telescope at Calar Alto, Spain, during April 1999 and February 2000. From these observations, a search for periodic variations in the light curve of Centaur 1997 CU<SUB>26</SUB> was made in both data sets. Also, the colour indices of Centaur 1999 UG<SUB>5</SUB> were measured for the first time, indicating that this object is one of the reddest bodies in the Solar System.