SMASH 1: A Very Faint Globular Cluster Disrupting in the Outer Reaches of the LMC?

We present the discovery of a very faint stellar system, SMASH 1, that is potentially a satellite of the Large Magellanic Cloud. Found within the Survey of the Magellanic Stellar History (SMASH), SMASH 1 is a compact (${r}_{h}={9.1}_{-3.4}^{+5.9}\,\mathrm{pc}$) and very low luminosity (${M}_{V}=-1.0\pm 0.9$, ${L}_{V}={10}^{2.3\pm 0.4}\,{L}_{\odot }$) stellar system that is revealed by its sparsely populated main sequence and a handful of red giant branch candidate member stars. The photometric properties of these stars are compatible with a metal-poor ($[\mathrm{Fe}/{\rm{H}}]=-2.2$) and old (13 Gyr) isochrone located at a distance modulus of ~18.8, i.e., a distance of $\sim 57\,\mathrm{kpc}$. Situated at 11fdg3 from the LMC in projection, its three-dimensional distance from the Cloud is $\sim 13\,\mathrm{kpc}$, consistent with a connection to the LMC, whose tidal radius is at least $16\,\mathrm{kpc}$. Although the nature of SMASH 1 remains uncertain, its compactness favors it being a stellar cluster and hence dark-matter free. If this is the case, its dynamical tidal radius is only $\lesssim 19\,\mathrm{pc}$ at this distance from the LMC, and smaller than the system's extent on the sky. Its low luminosity and apparent high ellipticity ($\epsilon ={0.62}_{-0.21}^{+0.17}$) with its major axis pointing toward the LMC may well be the tell-tale sign of its imminent tidal demise