2009MNRAS.397.1032B

With Two-Micron All-Sky Survey (2MASS) photometry and proper motions, Bonatto et al. suggested that FSR1767 is a globular cluster (GC), while with J and K NTT/SOFI photometry Froebrich, Meusinger & Scholz concluded that it is not a star cluster. In this study, we combine previous and new evidence that are consistent with a GC. For instance, we show that the horizontal branch (HB) and red giant branch (RGB) stars, besides sharing a common proper motion, have radial density profiles that consistently follow the King's law independently. Reddening maps around FSR1767 are built using the bulge RGB as reference and also Schlegel's extinction values to study local absorptions. Both approaches provide similar maps and show that FSR1767 is not located in a dust window, which otherwise might have produced the stellar overdensity. Besides, neighbouring regions of similar reddening as FSR1767 do not present the blue HB stars that are a conspicuous feature in the colour-magnitude diagram of FSR1767. We report the presence of a compact group of stars located in the central parts of FSR1767. It appears to be a detached post-collapse core, similar to those of other nearby low-luminosity GCs projected towards the bulge. We note that while the NTT/SOFI photometry of the star cluster FSR1716 matches perfectly that from 2MASS, it shows a considerable offset for FSR1767. We discuss the possible reasons why both photometries differ. We confirm our previous structural and photometric fundamental parameters for FSR1767, which are consistent with a GC.