We acknowledge a travel support to Calar Alto by the Deutsche Forschungsgemeinschaft. We thank K. Birkle for providing the Schmidt plate images as well as F.-L. Deubner, J. Isserstedt, and H.W. Yorke for helpful discussions. Additionally we appreciate encouraging comments of the referee D.J. Thomson.
© European Southern Observatory (ESO) 1998
Online publication: July 20, 1998