NGC 6749: a metal-poor halo globular cluster in a disc field rich in Mira variables

We present V, I photometry of the loose star cluster NGC 6749, and for the first time colour-magnitude diagrams are provided. We confirm that it is a globular cluster and its blue horizontal branch indicates that it is metal-poor. We derive a reddening of E(B— V) = 1.39± 0.04 and a distance from the Sun d⊙ = 7.3 ± 0.9 kpc (assuming a total-to-selective absorption R = 3.4). The cluster is projected very close to the Galactic plane, and the derived distance implies a Galactic coordinate Z ≈ — 300 pc. It is thus a halo globular cluster located close to the disc plane. We also discuss the properties of 78 newly discovered long-period variable stars, of which 75 are Miras, projected within 1°of the cluster centre. The variables do not appear to be associated with the globular cluster. From their periods, most of them belong to the metal-rich disc or bulge stellar populations.