A Faint Halo Star Cluster Discovered in the Blanco Imaging of the Southern Sky Survey

We present the discovery of a faint, resolved stellar system, BLISS J0321+0438 (BLISS 1), found in Dark Energy Camera data from the first observing run of the Blanco Imaging of the Southern Sky (BLISS) survey. BLISS J0321+0438 (BLISS 1) is located at ({α }₂₀₀₀,{δ }₂₀₀₀)=(177\buildrel{\circ}\over{.} 511,-41\buildrel{\circ}\over{.} 772) with a heliocentric distance of {D}_⊙ ={23.7}_-1.0^+1.9 {kpc}. It is a faint, {M}_V={0.0}_-0.7^+1.7 {mag}, and compact, {r}_h={4.1}_-1⁺¹ {pc}, system consistent with previously discovered faint halo star clusters. Using data from the second data release of the Gaia satellite, we measure a proper motion of ({μ }_α \cos δ ,{μ }_δ )=(-2.37+/- 0.06,0.16+/- 0.04) mas yr^-1. Combining the available positional and velocity information with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC), we find that it is unlikely that BLISS J0321+0438 (BLISS 1) originated with the LMC.