SIMBAD references

We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada-France-Hawaii Telescope g and i photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour-magnitude diagram shows that it is quite metal-poor, old (13.0 ±1.0 Gyr), and at a distance of 61.4 ±1.0 kpc, partly based on two RR Lyrae stars. The system is faint (M_V=_–2.8+0.2^_–0.3 mag) and compact (r_h=_11.4±_1.0 pc). From the spectroscopy, we constrain the systemic metallicity ( [Fe/H]_spectro = -1.8 ±0.1 dex) but the metallicity and velocity dispersions are both unresolved. Using Gaia DR2, we infer a mean proper motion of (µ_α^*,µ^_δ)=(0.51±_0.28,–0.83±_0.27) mas yr^–1, which, combined with the system's radial velocity (<v_r>=_–70.2±_0.5 km s^–1), translates into a halo orbit with a pericenter and apocenter of 40.7 ^+5.6_–14.7 and 85.6^+17.2_–5.9 kpc, respectively. Overall, Laevens 3 shares the typical properties of the Milky Way's outer halo globular clusters. Furthermore, we find that this system shows signs of mass segregation that strengthens our conclusion that Laevens 3 is a globular cluster.