Key points are not available for this paper at this time.
New observations of the galactic Cepheids AQ Car (period = 9d.77), XX Cen (10d.95), XY Car (12d.44), TT Aql (13d.75), XX Car (15d.71), and XZ Car (16d.65) are presented. 365 photometric measures in the UBVRIc system and 297 radial velocities are combined with previous data to produce light, color, and velocity curves of almost total phase coverage.
Coulson et al. (1985) studied this question.