Anchors for the Cosmic Distance Scale: the Cepheid QZ Normae in the Open
  Cluster NGC 6067
  Cepheids are key to establishing the cosmic distance scale. Therefore it's
important to assess the viability of QZ Nor, V340 Nor, and GU Nor as
calibrators for Leavitt's law via their purported membership in the open
cluster NGC 6067. The following suite of evidence confirms that QZ Nor and V340
Nor are members of NGC 6067, whereas GU Nor likely lies in the foreground: (i)
existing radial velocities for QZ Nor and V340 Nor agree with that established
for the cluster (-39.4+-1.2 km/s) to within 1 km/s, whereas GU Nor exhibits a
markedly smaller value; (ii) a steep velocity-distance gradient characterizes
the sight-line toward NGC 6067, thus implying that objects sharing common
velocities are nearly equidistant; (iii) a radial profile constructed for NGC
6067 indicates that QZ Nor is within the cluster bounds, despite being 20' from
the cluster center; (iv) new BVJH photometry for NGC 6067 confirms the cluster
lies d=1.75+-0.10 kpc distant, a result that matches Wesenheit distances
computed for QZ Nor/V340 Nor using the Benedict et al. (2007, HST parallaxes)
calibration. QZ Nor is a cluster Cepheid that should be employed as a
calibrator for the cosmic distance scale.
