An ultra-faint galaxy candidate discovered in early data from the magellanic satellites survey

We report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS  J0644−5953 (Pictor II or Pic II) is a low surface brightness ($\mu ={28.5}_{-1}^{+1}magarcsec{}^{-2}$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of ${45}_{-4}^{+5}kpc$. The physical size ($r_{1/2}={46}_{-11}^{+15}pc$) and low luminosity ($M_V=-{3.2}_{-0.5}^{+0.4}mag$) of this satellite are consistent with the locus of spectroscopically confirmed ultra-faint galaxies. MagLiteS  J0644−5953 (Pic II) is located ${11.3}_{-0.9}^{+3.1}kpc$ from the Large Magellanic Cloud (LMC), and comparisons with simulation results in the literature suggest that this satellite was likely accreted with the LMC. The close proximity of MagLiteS  J0644−5953 (Pic II) to the LMC also makes it the most likely ultra-faint galaxy candidate to still be gravitationally bound to the LMC.