Fr.: Antlia 2
A Milky-Way satellite in the constellation → Antlia. Antlia. It was originally detected in Gaia DR2 data using a combination of → RR Lyrae, → proper motions, → parallaxes and shallow → broad-band photometry. Antlia 2 is located behind the → Galactic disk at a latitude of b ~ 11° and spans 1.26 degrees, which corresponds to ~ 2.9 kpc at its distance of 130 kpc. While similar in extent to the → Large Magellanic Cloud, Antlia 2 is orders of magnitude fainter with MV = -8.5 mag, making it by far the lowest surface brightness system known (at 32.3 mag/arcsec2), ~ 100 times more diffuse than the so-called ultra diffuse galaxies. The dwarf's systemic velocity is 290.9 ± 0.5 km s-1, its velocity dispersion, 5.7 ± 1.1 km s-1, and mean → metallicity, [Fe/H]= -1.4 (Torrealba et al., 2018, arXiv:1811.04082).