SIMBAD references

We present new B,V photometry for the globular clusters NGC 6496, 6624, and 6637. These clusters were believed to be members of the disk system of globular clusters. We determined reddening and distances and derive minimum inclinations of the orbital planes of the clusters. For all clusters, these inclinations are too large to justify the term "disk cluster". Metallicities estimated from CMD morphological indicators are significantly lower than those derived from integrated aperture photometry and suggest that all three clusters are halo globular clusters with large eccentric orbits. Isochrone fitting is compatible with all three clusters being very old. These results, together with the fact that published proper motions revealed "halo" clusters with orbits very closely confined to the disk, lets the usual halo - disk distinction among galactic globular clusters appear questionable. More and better metallicity determinations as well as reddening and distances are needed, before the separation of globular clusters in a disk and a halo population gains a physical significance.