We thank Dr. D. Kilkenny for providing the differential photometric data used in the temperature analysis. We thank the referee, Dr. D. Kurtz, for his helpful comments. We acknowledge financial support from the former Department of Education of Northern Ireland and the UK PPARC (grant Ref PPA/G/S/1998/00019).
© European Southern Observatory (ESO) 2000
Online publication: June 20, 2000