The BOSS Great Wall is a galaxy wall, a subtype of galaxy filaments, that was discovered early 2016. It is one of the largest superstructures in the observable universe. It contains perhaps 10 000 times the mass of the Milky Way. It is 1 billion light years across, and contains 830 visible galaxies, as well as many others that are invisible (dark galaxies). It contains five times the density compared to the standard cosmological density of the universe. Its redshift is about z=0.47 (z times Hubble length ≈ 6800 million light years). Although this structure may look grand in size to us, we may not be able to call it one solid structure just yet. This part of the sky has five times as many galaxies as an average space in the sky, but we know the universe is still expanding. This brings about the question of whether they are all moving together or are slowly separating as the universe expands.
It was discovered using the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey, hence its name, by H. Lietzen, E. Tempel, L. J. Liivamägi, A. Montero-Dorta, M. Einasto, A. Streblyanska, C. Maraston, J. A. Rubiño-Martín and E. Saar.